A series of ferrocenyl substituted hydrazones (I–VII) derived from ferrocene carboxaldehyde and substituted hydrazides have been prepared and characterized by FTIR, 1H NMR spectroscopy, and crystallographic studies. The single-crystal X-ray analysis for III·0.5H2O·0.5CH3CN (CIF file CCDC no. 1968937) further authenticates the structural motif of the synthesized compounds. The C(11) of ferrocene carboxaldehyde is linked with N(1) of the hydrazide moiety with a bond length of 1.283(5) Å, confirming the binding of the two structural units present in the final product. They were preliminarily screened for their antimicrobial activity and demonstrate good results. The free radical scavenging activity for the compounds (III, IV) has been found to be more than 90% when compared with the ascorbic acid. The total antioxidant capacity and total reducing power assays for VI show significant activity whereas the data for the other compounds are also encouraging. Quantum chemical calculations at the DFT level predict that compound II is the softest while VII is the hardest within the series, resultantly II can be used as a synthon for further chemical reactions.

Mitigating the climate impact from aviation remains one of the tougher challenges in adapting society to fulfill stated climate targets. Long-range aviation cannot be electrified for the foreseeable future and the effects of combusting fuel at high altitude increase the climate impact compared to emissions of green-house gasses only, which further limits the range of sustainable fuel alternatives. We investigate seven different pathways for producing aviation biofuels coupled with either bio-energy carbon capture and storage (BECCS), or bio-energy carbon capture and utilization (BECCU). Both options allow for increased efficiency regarding utilization of feedstock carbon. Our analysis uses process-level carbon- and energy balances, with carbon efficiency, climate impact and levelized cost of production (LCOP) as primary performance indicators. The results show that CCS can achieve a negative carbon footprint for four out of the seven pathways, at a lower cost of GHG reduction than the base process option. Conversely, as a consequence of the electricity-intensive CO2 upgrading process, the CCU option shows less encouraging results with higher production costs, carbon footprints and costs of GHG reduction. Overall, pathways with large amounts of vented CO2, e.g., gasification of black liquor or bark, as well as fermentation of forest residues, reach a low GHG reduction cost for the CCS option. These are also pathways with a larger feedstock and corresponding production potential. Our results enable a differentiated comparison of the suitability of various alternatives for BECCS or BECCU in combination with aviation biofuel production. By quantifying the relative strengths and weaknesses of BECCS and BECCU and by highlighting cost, climate and carbon-efficient pathways, these results can be a source of support for both policymakers and the industry. © 2023 The Author(s)

This study examined various source-separating sanitation systems to evaluate their environmental performance, providing decision-makers with insights for selecting an appropriate system for a newly developed neighborhood in Sweden. A full consequential LCA was conducted to account for resource recovery and substitution. The local wastewater treatment plant WWTP was modeled as a reference. Secondly, a urine recycling system was introduced to treat 75 % of the collected urine, with the remainder piped to the WWTP. Thirdly, a black and greywater (BW&GW) treatment system handling all generated wastewater was examined. Finally, a hybrid source-separating system combining urine, black, and greywater was investigated. The results indicated that the four scenarios exhibited global warming potentials (GWP) of 78, 62, 32, and 24 kg CO2-eq per PE/ y. Recycling urine as fertilizer led to a 20 % reduction in the GWP of the reference. It also reduced other impact categories, with a 55 %, 65 %, and 45 % reduction in eutrophication, ozone depletion, and acidification, respectively. The BW&GW system achieved a 60 % reduction over the reference GWP, mainly due to fertilizer, biogas, and cleanwater recovery. Integrating urine, black, and greywater recycling in the final scenario achieved a 25 % reduction compared to the BW&GW scenario, primarily due to lowering of the ammonia stripping GWP and the additional fertilizer recovery. Based on sensitivity analyses, switching citric acid for sulfuric acid reduced the GWP of the urine stabilization unit process by 101 %, from 15.47 to -0.14 kg CO2-eq per PE/ y. Ultimately, the findings suggest that the fully decentralized source-separating sanitation system incorporating urine, blackwater, and greywater recycling, particularly when combined with 70 % energy recovery at the urine concentrator, is most favorable. © 

Biological methanation of syngas from pyrolysis and gasification – promising concepts for implementation The need for increased biogas production is significant, and in the EU, there are plans for a substantial expansion in the coming years through the RePowerEU initiative. Part of the increase will come from the expansion of conventional digestion technology, where organic materials such as food waste, manure, and crop residues are used for biogas production. However, to meet the future increased demand, it is also necessary to utilize more difficult-to-digest substrates, such as biomass rich in lignocellulose, for biogas production. This could be forest residues such as branches and tops, sawdust, or bark. This type of substrates cannot be used in a conventional digestion process, and other technology chains are therefore required to convert such biomass into biomethane. This can be done by first converting the biomass into syngas through a thermochemical process such as gasification or pyrolysis. This is followed by a methanation process where the syngas is converted into biogas, and finally, the gas is upgraded to reach biomethane quality. These types of technology chains are not currently available on a commercial scale, but they have been demonstrated, for example, through the Gobigas project, where gasification was followed by catalytic methanation for biomethane production. As full-scale implementation of catalytic methanation of bio-syngas has not yet been achieved, thereis a need to develop alternative conversion technologies that can more cost-effectively achieve the methanation of woody biomass. One possible opportunity for to this is to apply biological methanation instead of a catalytic process. A biological process comes with several advantages, including a greater ability to handle contaminants, higher selectivity in the conversion of syngas, and operation at relatively low temperature and pressure, which simplifies material selection and reactor design. RISE, together with its partners, are developing a concept based on biological methanation of syngas. This project has examined the biological process's ability to handle contaminants in syngas through continuous experiments in carrier-filled trickle bed reactors with an active volume of 5 liters. The process's ability to handle and break down contaminants is an important parameter that can affect and simplify the design of the gas cleaning that occurs after gasification or pyrolysis. Another aspect of the project has been to put the experimental results into context at the concept and system level. Different production techniques for syngas have been mapped out, which could be combined with biological methanation. Based on the mapping, three types of plants have been selected for more detailed analyses of techno-economics, carbon footprint, and opportunities for increased carbon efficiency. The methanation experiments lasted for 552 days, and overall, it was a stable process with high turnover of syngas and high methane production over a long time. There have been some operational disturbances, mainly related to the supply of gas to the process (i.e. delivery of gas cylinders). However, biochemical inhibition or disturbances have been rare, demonstrating a high robustness for biological methanation of syngas. The breakdown of contaminants has been excellent in the process, with levels decreasing below the detection limit. At the same time, as contaminants have been continuously added to the process, microbiology has been able to maintain high turnover of hydrogen and carbon monoxide to methane. The specific methane production was high both during the reference period without contaminants and during the experimental periods with added contaminants. During long periods, the specific methane production has been around 4 L CH4/Lbed volume /day, which is about 4 times higher than our previously achieved results. The transition to thermophilic temperature and using carriers with higher effective surface area has contributed to this increase. During the project, three types of plants have been selected for more detailed analysis: 1) Gasification with Cortus process, which generates a relatively clean syngas with minimal purification needs before biological methanation. There is no need for co-location with a heating plant, but it is an advantage if there is access to the district heating network to sell waste heat. 2) Gasification with Bioshares' concept, where the gasifier is integrated into a larger cogeneration plant and where the produced syngas is purified with an RME-scrubber before biological methanation. Co-location with a larger cogeneration plant provides interesting synergies and integration opportunities, but also sets the boundaries for where the plants can be located. 3) Slow pyrolysis according to Envigas' concept, where the primary product is biochar and where the produced syngas is seen as a by-product. The syngas contains some impurities but generally requires no other purification than cooling to the right temperature (condensing out tars) before being added to biological methanation. This type of plant differs from plant types 1-2 in that the syngas formed is not the primary product, and the syngas has a relatively low energy value compared to the others. Syngas from plant types 2 and 3 contains some hydrocarbons (C1-C3) that are considered inert over the methanation step and therefore do not negatively affect the process. This means that heavier hydrocarbons do not need to be removed upstream, which would likely have been required with catalytic methanation. This leads to a higher system efficiency, and the need for reactor capacity for biological methanation decreases since there is less gas to be processed (more of the end-product consists of hydrocarbons already formed during the thermochemical conversion upstream). For all plant types, downstream of the methanation step, there is a need for further gas purification and upgrading. During the upgrading step carbon dioxide is separated to reach the product specification required by the end user. If long distance distribution is required a final process step consisting of a liquefaction plant for the production of liquid biogas (LBG) can be added to the concept. As another option, the systems can be supplemented with treatment of the carbon dioxide flow out of the upgrading plant, where the flow is processed by drying, compression, and cooling to produce liquid carbon dioxide. For plant type 2, where benzene is present in the syngas, this gas is expected to be separated with relatively high precision in the system and thereby generate a small flow of liquid benzene as a side product. The carbon dioxide emissions for the final product LBG are in the range of 1.6 to 2.6 gCO2-eq/MJLBG, which compares favorably to other types of second-generation biofuels. Compared to fossil gas, the reduction in greenhouse gas emissions is 96-97%. The carbon efficiency of the systems can be significantly increased if excess carbon dioxide is utilized either through BECCS or BECCU. If the carbon dioxide stream from the upgrading plant is processed into liquid carbon dioxide, the production cost is estimated to be 187-204 SEK/ton. If the product is to be sent to permanent storage the cost for transportation and storage would need to be added to estimate total cost of BECCS, but this is out of scope for the current project.. Assuming that BECCS is applied and that the entire carbon sink is allocated to the final product LBG, this will result in negative emissions in the range of -35 to -104 gCO2-eq/MJLBG. An alternative is to utilize excess carbon dioxide directly in the methanation process by boosting incoming gas with extra hydrogen. Hydrogen and carbon dioxide are then converted by methanogens, which generates extra methane. Since the addition of extra hydrogen is assumed to come from electrolysis, the additional methane production can likely be classified as electrofuel, so-called e-methane. The techno-economic evaluation results in a production cost ranging from 740 to 1300 SEK/MWhLBG, including all sensitivity scenarios. The lower price scenarios include a lower investment cost, which can be assumed to represent cases with public investment support. Overall, a large part of the scenarios are considered to be within the range of what can be considered market relevant production costs. This leads to the conclusion that there is techno-economic potential at this stage to justify continued development of concepts based on biological methanation of syngas. With scaling up and continued development in the right direction, the concepts may eventually lead to cost-effective utilization of forest residues for the production of biomethane at a commercially relevant scale. The next step in the development is scaling up to pilot scale, which will take place during 2023-2025 through an EU-funded project and will be carried out by RISE, Wärtsilä, Cortus and Swedish Gas Association. A pilot plant for biological methanation will then be operated with syngas from Cortus' gasifier in Höganäs.

BECCS from biogas production

Global CO₂ emissions amount to about 40 Gtonnes/year and they need to be rapidly reduced if we are to meet adopted climate targets. To achieve this, a variety of measures is needed, such as more electrification, reduced use of fossil energy, more renewable energy, energy efficiency improvements and CCS (Carbon Capture and Storage). However, this will not be enough, but will also require so-called negative emissions, which means that CO₂ is removed from the atmosphere through, for example, increased afforestation, increased carbon storage in soil (e.g. biochar), or by capturing and storing CO₂ of biogenic origin in geological formations, also known as bio-CCS or BECCS. At global level, the need for negative emissions is estimated to be in the order of several billion tonnes of CO₂ per year if it shall be possible to reach the 1.5-degree target and net zero emissions by 2050. At national level, Sweden’s target is to achieve net zero emissions by 2045 and from then on to be climate positive. This means that territorial emissions from the 1990 level must be reduced by at least 85% by 2045 and that the remaining 15 % will be eliminated by means of so-called supplementary measures including bio-CCS as an important measure.

The need for bio-CCS is significant and the actors who can deliver biogenic CO₂ at the right quality and at low cost will have good business opportunities in an expected future global marketplace for negative emissions. With this project, we have investigated the opportunities CO₂ from biogas production has to contribute to bio-CCS in Sweden. At biogas plants that produce vehicle gas, there is already equipment to separate CO₂ from biogas, so-called upgrading technologies. By modifying and extending this technology, pure liquid CO₂ can be generated. The CO₂ is then transported to terminals in Swedish ports while waiting for transport by ship to the place for permanent storage.

The project has studied gas purification and liquefaction based on the four most common upgrading techniques: water scrubber, PSA (pressure swing adsorption), membrane separation and amine scrubber. The residual gas (the CO₂-rich gas leaving the upgrading equipment) differs between different upgrading technologies, which affects the need for subsequent purification steps. Results from modelling and simulation have led to two proposed technology chains. For amine scrubbers, a simple process of compression, drying and liquefaction is sufficient to achieve the CCS specification of the liquid CO₂. PSA, membranes and water scrubbers require more advanced gas purification including a two-phase separation and recirculation of gases with low dew point, such as O₂ and CH₄. The recirculated gas is recycled to the inlet of the upgrading process, leading to the double benefit of increased amount of valuable CH₄ product and further reduction of greenhouse gas emissions to the atmosphere. A side effect is that the need for conventional residual gas management is eliminated.

Cost calculations have been carried out for biogas plants with a production capacity of 20, 50 and 120 GWh/year. With an availability of 95% and a CO₂ content of 39% in raw biogas (gas before upgrading), this equates to a CO₂ production of 2,400, 5,900 and 14,200 tons/year, respectively. A starting point for the study has been that systems for large-scale bio-CCS/CCS will be established and that this will lead to the construction of several CO₂ terminals in Swedish ports. Furthermore, it is assumed that these terminals allow third-party access where a supplementary volume of biogenic CO₂ from biogas plants can constitute a portion of the total managed amount. Around each terminal, clusters of biogas plants are estimated to emerge, which each can deliver approximately 20,000–100,000 tons CO₂ per year. The distribution from biogas plants to port terminals may be done by truck transport where the loading capacity amounts to 34 tons of CO₂. After the terminal, CO₂ is transported by ship to the place for permanent storage.

The cost of producing liquid CO₂ from biogas depends on local conditions such as CO₂ flow, O₂ content, upgrading technology, new or existing plant, transport distance to terminal, etc. In order to determine what the cost will be for each individual biogas plant, it is necessary to adapt the calculations to local conditions. Through the project, generic calculations have been carried out which show that large biogas plants have good opportunities to produce liquid CO₂ at competitive costs, but also that there is a strong scaling effect. For example, the cost is about SEK 200–300/tonne CO₂ for new plants with 120 GWh in annual biogas production. With investment support, the cost drops to about SEK 150–200/tonne. For new plants in the intermediate segment (50 GWh/year), the cost is slightly higher, SEK 300–450/tonne (without capital grants) and SEK 190–275/tonne (with capital grants). For smaller plants (20 GWh/year), the cost rises significantly, especially for water scrubbers.

The transport cost up to the terminal is affected by the distance and amount of CO₂ handled. For example, the cost of truck transport from larger biogas plants is about SEK 200/tonne at 100 km one-way to terminal. The total cost of bio-CCS from biogas including terminal handling, ship transport and final storage is affected by many parameters and there are uncertainties in cost estimates along the entire chain. In a calculation example for a biogas plant with membrane upgrading, 100 km of truck transport one way to terminal in Gothenburg and transport and final storage according to Northern Light's concept, the total cost was estimated at SEK 830–1020/tonne CO₂ for larger biogas plants (120 GWh/year).

When the bio-CCS from biogas is introduced, negative emissions arise from two sources, firstly from the final storage itself, which is the main part, and secondly by reducing CH₄ emissions from the upgrading plants, which is a smaller, but not negligible part. The total CO₂ efficiency of the value chain is determined by energy consumption, transport distance, selected storage solution and CH₄ slip before the introduction of bio-CCS. Emissions from truck transport are small in this context. In total, CO₂ efficiency in many cases amounts to close to 100%, i.e. net emissions in the value chain up to final storage are close to zero. For plants that initially had relatively high CH₄ emissions from the upgrading unit, the climate benefit is even greater, with CO₂ efficiency throughout the chain being well over 100%.

A driving hypothesis in the project has been that CO₂ from biogas can be the CO₂ stream in society that is one of the lowest-hanging fruits and that the value chain is well placed to be more cost-effective than other concepts for bio-CCS. Based on the results of the project, we can conclude that the hypothesis is likely to hold. The cost up to the terminal will in many cases likely be lower compared to capture and liquefaction from large point sources. With efficient technology and distribution solutions, biogas producers should be able to contribute to bio-CCS to a fairly large extent, up to about 10% of Sweden's need for negative emissions. For biogas operators, this would mean a broadening of the business where CO₂ is seen as a valuable product which complements the revenues from the production of biomethane. 

I regleringsbrevet för 2023 fick Energimyndigheten i uppdrag av regeringen att utreda hur solcellspaneler och vindturbinblad till vindkraftverk i högre utsträckning ska kunna tas om hand på ett giftfritt och cirkulärt sätt i enlighet med avfallshierarkin. Redovisningen av detta regeringsuppdrag, rapporten Från avfall till resurs – Förslag för en mer cirkulär hantering av solcellspaneler och vindturbinblad, ER 2024:11, baseras på denna underlagsrapport som har tagits fram av forskningsinstitutet RISE på uppdrag av Energimyndigheten. Analyser, slutsatser och förslag/rekommendationer som framförs i rapporten är författarnas egna.En fortsatt utbyggnad av fossilfri elproduktion är av stor vikt för att vi ska kunna nå Sveriges energi- och klimatmål. För att utbyggnaden i sig ska vara hållbar är det viktigt att vi redan nu planerar för hur avfallet från dessa elproduktionsanläggningar ska förebyggas, minimeras och sedan hanteras.Det finns redan i dagsläget aktörer som har utvecklat och håller på att utveckla ett flertal olika lösningar för ökad cirkularitet. Dessa möjligheter kan tas tillvara och främjas genom regelbunden kartläggning och genom att arbeta gemensamt inom EU. Genom ett sådant arbete finns det också större möjligheter att etablera industriella värdekedjor i Sverige för hanteringen av avfallet från solcellspaneler och vindturbinblad.En cirkulär hantering av avfall ger ett betydligt mindre avtryck på miljön än det som en linjär hantering ger upphov till. Det är viktigt att de aktörer som tillhandahåller fossilfri elproduktion tar ansvar under hela livscykeln och att det finns goda förutsättningar för aktörerna att göra det.

Kraft lignin, a by-product from the production of pulp, is currently incinerated in the recovery boiler during the chemical recovery cycle, generating valuable bioenergy and recycling inorganic chemicals to the pulping process operation. Removing lignin from the black liquor or its gasification lowers the recovery boiler load enabling increased pulp production. During the past ten years, lignin separation technologies have emerged and the interest of the research community to valorize this underutilized resource has been invigorated. The aim of this review is to give (1) a dedicated overview of the kraft process with a focus on the lignin, (2) an overview of applications that are being developed, and (3) a techno-economic and life cycle asseeements of value chains from black liquor to different products. Overall, it is anticipated that this effort will inspire further work for developing and using kraft lignin as a commodity raw material for new applications undeniably promoting pivotal global sustainability concerns.

Lignocellulosic biomass is renewable and one of the most abundant sources for the production of high-value chemicals, materials, and fuels. It is of immense importance to develop new efficient technologies for the industrial production of chemicals by utilizing renewable resources. Lignocellulosic biomass can potentially replace fossil-based chemistries. The production of fuel and chemicals from lignin powered by renewable electricity under ambient temperatures and pressures enables a more sustainable way to obtain high-value chemicals. More specifically, in a sustainable biorefinery, it is essential to valorize lignin to enhance biomass transformation technology and increase the overall economy of the process. Strategies regarding electrocatalytic approaches as a way to valorize or depolymerize lignin have attracted significant interest from growing scientific communities over the recent decades. This review presents a comprehensive overview of the electro-catalytic methods for depolymerization of lignocellulosic biomass with an emphasis on untargeted depolymerization as well as the selective and targeted mild synthesis of high-value chemicals. Elec-trocatalytic cleavage of model compounds and further electrochemical upgrading of bio-oils are discussed. Finally, some insights into current challenges and limitations associated with this approach are also summarized. © 2022 by the authors. 

The demand for cheap, healthy, and sustainable alternative protein sources has turned research interest into microbial proteins. Mycoproteins prevail due to their quite balanced amino acid profile, low carbon footprint and high sustainability potential. The goal of this research was to investigate the capability of Pleurotus ostreatus to metabolize the main sugars of agro-industrial side streams, such as aspen wood chips hydrolysate, to produce high-value protein with low cost. Our results indicate that P. ostreatus LGAM 1123 could be cultivated both in a C-6 (glucose)- and C-5(xylose)-sugar-containing medium for mycoprotein production. A mixture of glucose and xylose was found to be ideal for biomass production with high protein content and rich amino acid profile. P. ostreatus LGAM 1123 cultivation in a 4 L stirred-tank bioreactor using aspen hydrolysate was achieved with 25.0 ± 3.4 g L−1 biomass production, 1.8 ± 0.4 d−1 specific growth rate and a protein yield of 54.5 ± 0.5% (g/100 g sugars). PCA analysis of the amino acids revealed a strong correlation between the amino acid composition of the protein produced and the ratios of glucose and xylose in the culture medium. The production of high-nutrient mycoprotein by submerged fermentation of the edible fungus P. ostreatus using agro-industrial hydrolysates is a promising bioprocess in the food and feed industry. © 2023 by the authors.

Agricultural land shrinkage, decreasing global water resources, population increase and malnutrition highlight the need for new food sources. Single-cell protein derived from microorganisms could be a solution to high protein demand. The aim of this work was to optimize the cultivation conditions for single-cell protein production by Pleurotus ostreatus LGAM 1123 in submerged cultures and valorize fiber sludge, a low cost industrial side stream from the pulp and paper industry, as a substrate for single-cell protein (SCP) production. A study on the effect of different cultivation conditions on fungal growth and protein production has been conducted. Response surface methodology was used to investigate the combined effect of the most important factors (glucose and yeast extract medium concentrations) and optimize the process. A maximum protein production of 10.0 ± 0.9 g L-1 was found for the submerged cultivation of the fungus in a 3.5 L stirred-tank bioreactor, while the biomass produced and its total protein content were 26.0 ± 2.0 g L-1 and 44.8 ± 0.8%, respectively. As an industrial application, a cellulosic hydrolysate obtained after enzymatic hydrolysis of fibre sludge in the optimized medium composition was used. Fibre sludge was shown to be an excellent feedstock for SCP production achieving productivity and protein content very similar to glucose fermentations. Single-cell protein of P. ostreatus presented higher amino acid scores compared to the recommended ones for valine, leucine, and aromatic amino acids in human nutrition. Therefore, P. ostreatus biomass could stand as an alternative vegan protein source due to its high protein content and amino acid composition. 

The subject of lignin structure, critical for fundamental and practical reasons, is addressed in this study that includes a review of the methods applied to elucidate macromolecular branching. The recently available approaches for determination of the absolute molecular mass of spruce milled wood lignin (MWL) along with the quantification of terminal groups clearly indicate that MWL is significantly branched and cross-linked (with ∼36% lignin units partaking in these linkages). Results from independent methods imply that about half of the branching and crosslinking linkages involve aromatic rings, predominantly 5-5′ etherified units; meanwhile, a significant number of linkages are located in the side chains. Quantitative 13C NMR analyses suggest that the branches involve different aliphatic ether (alkyl-O-alkyl) types at the α- and γ-positions of the side chain, with intact β-O-4 linkages. While the exact structures of these moieties require further investigation, our results point to the fact that conventional lignification theory disagrees with the presence of such key moieties in softwood MWL and the observed high degree of branching/crosslinking. Potential reasons for the noted discrepancies are discussed.

Sugar-based biorefineries have faced significant economic challenges. Biorefinery lignins are often classified as low-value products (fuel or low-cost chemical feedstock) mainly due to low lignin purities in the crude material. However, recent research has shown that biorefinery lignins have a great chance of being successfully used as high-value products, which in turn should result in an economy renaissance of the whole biorefinery idea. This critical review summarizes recent developments from our groups, along with the state-of-the-art in the valorization of technical lignins, with the focus on biorefinery lignins. A beneficial synergistic effect of lignin and cellulose mixtures used in different applications (wood adhesives, carbon fiber and nanofibers, thermoplastics) has been demonstrated. This phenomenon causes crude biorefinery lignins, which contain a significant amount of residual crystalline cellulose, to perform superior to high-purity lignins in certain applications. Where previously specific applications required high-purity and/or functionalized lignins with narrow molecular weight distributions, simple green processes for upgrading crude biorefinery lignin are suggested here as an alternative. These approaches can be easily combined with lignin micro-/nanoparticles (LMNP) production. The processes should also be cost-efficient compared to traditional lignin modifications. Biorefinery processes allow much greater flexibility in optimizing the lignin characteristics desirable for specific applications than traditional pulping processes. Such lignin engineering, at the same time, requires an efficient strategy capable of handling large datasets to find correlations between process variables, lignin structures and properties and finally their performance in different applications.

The pulp and paper (P&P) industry holds significant global importance. However, the industry’s processes substantially demand water and energy resources. Consequently, there is a pressing need for the industry to adopt more sustainable production practices, aiming to trim environmental impact and strengthen resilience against climate change. Recent research has highlighted the potential for substantial increases in Swedish biogas production using anaerobic wastewater (WW) treatment methods within P&P mills. The P&P sector traditionally relies on aerobic biological WW treatment, overlooking the valuable opportunity for WW resource recovery. This study aims to evaluate anaerobic moving bed biofilm reactors (AnMBBR) to enhance energy recovery while enabling treatment capacity for the P&P industry’s anaerobic WW treatment. The results of this study showed the resilience of the AnMBBR system. It proved capable of recovering from overload conditions and operating even during prolonged periods at low pH levels. However, the system removes mainly soluble COD, suggesting higher capabilities on P&P WW with a high fraction of soluble COD. Its ability to produce methane-rich biogas demonstrates efficient gas production while maintaining simple operational procedures. 

Den här sammanfattande rapporten utgör en syntes av den tillgängliga kunskapen och erfarenheterna i Sverige kring återvinning och återanvändning av resurser från avlopp. Sammanställningen är resultatet av ett omfattande arbete av Projekt­gruppen i dialog med en stor mängd olika aktörer inom relevanta områden, som myndigheter, kommunala VA-organisationer, högskolor med flera. Tillsammans med de delsynteser som rör olika temaområden, är denna kunskap tänkt att stödja både offentliga och privata aktörer som är centrala för omställningsprocessen till en mer cirkulär hantering av resurser från avlopp. Det långsiktiga målet är ett hållbart och, framför allt, mer motståndskraftigt samhälle där resurser ur avlopp kan utgöra en viktig pusselbit. Rapporten är avsedd att hjälpa till att hitta, navigera och tolka den stora mängd kunskap som redan finns, samt att utforska möjliga lösningar och vägar framåt mot en ökad implementering av cirkulära lösningar. Avloppsvatten innehåller inte bara näringsämnen som kan möta många av de behov som finns inom svenskt jordbruk, utan också betydande mängder energi. Denna energi används idag bara i begränsad omfattning, men den har potential att bli en viktig komponent i Sveriges framtida förnybara energimix. Utöver dessa resurser utgör också vattnet en livsviktig resurs, inte bara för oss människor utan även för de ekosystem vi är beroende av. Även vi i Sverige behöver återvinna och återanvända vattenresurserna i större utsträckning för att möta utmaningar som vattenbrist och försämring av våra naturliga vattenresurser, bland annat orsakad av klimatförändringar. Avloppen innehåller även andra resurser som samhället till viss del redan har uppmärksammat som potentiella alternativ för att möta våra behov. I kombination med en effektivare resursanvändning kan en återvinning och återanvändning av resurserna som finns i avloppet göra Sverige mindre beroende av import av ofta fossila resurser, vilket ökar Sveriges motståndskraft i kristider. Omställningen kan också bidra till att säkra kritisk infrastruktur och till att mer hållbara cirkulära lösningar som tillgodoser våra planetära gränser tillämpas. Förutom resurserna så innehåller avlopp även föroreningar eftersom avlopp är en naturlig samlingspunkt för många utsläpp i samhället, från både hushåll, industri och andra utsläppskällor. Hit räknas exempelvis läkemedelsrester och andra organiska och oorganiska mikroföroreningar, som samhället redan har identifierat som problematiska för både miljön och människors hälsa. En holistisk hantering av avloppsfraktioner som möjliggör återvinning och återanvändning av värdefulla resurser samtidigt som föroreningar kan tas bort från kretsloppet är således vägen framåt för svensk avloppshantering. Här föreslår projektgruppen en samhällsanpassad kombination av källsorteringssystem och resursanläggningar som kan utvecklas i takt med samhällets utveckling och omställning för en allt högre grad av resursåtervinning. Denna lösning ger en reell möjlighet att börja med en implementering av resursåtervinning nu eftersom befintlig infrastruktur kan nyttjas och kompletteras eller byggas om successivt med samhällets omställ­ning. Införandet av olika källsorterande eller resursåterbrukande åtgärder i vissa hushåll eller bostadsområden och återvinning av resurser i befintliga avloppsreningsverk kan realiseras parallellt och gynnar direkt både en cirkulär resurs-användning och ett bättre resursutnyttjande i avloppshanteringen. Syntesrapporten visar att det redan idag finns både tekniker och lösningar för att återvinna och återanvända olika resurser från avlopp. Dessutom pågår mycket forskning och utveckling kring teknikoptimering och innovation som med en tydlig satsning skulle kunna ge Sverige ett teknologi- och innovationsförsprång i den omställningsprocess som flera länder har initierat. Genomgången av erfarenheter visar också att acceptansen för användning av resurser som utvinns från avlopp till stor del redan finns idag, men att det finns en stor potential att öka denna acceptans bland annat genom ett tydligare arbete från myndigheternas sida. Här kan det nämnas att trots att existerande regelverk på en övergripande nivå redan främjar en utökad användning av avloppsresurser så kvarstår brister på vägledning och juridiska osäkerheter som några av de största hindren för en ökad återvinning och återanvändning av resurser från avlopp. För att övervinna hinder inom återvinning och återanvändning krävs ett bättre samarbete och ökad kunskap hos svenska myndigheter. Olika initiativ för att främja kunskapsutbyte och kunskapsuppbyggnad kan hjälpa till att uppnå detta. Projektgruppen hoppas att även denna syntesrapport delvis kan bidra till det.  Syntesen visar att det även finns olika verktyg tillgängliga för att bedöma even­tuella risker med återanvändning eller återvinning av resurser, eller för att välja de bästa lösningarna bland flera alternativ. Dessa verktyg kan ge ett värdefullt stöd i beslutsprocesser även framöver, dock behöver det beaktas att det alltid kommer finnas aspekter som inte kommer kunna kvantifiera eller bedömas. Det är därför av vikt att alla involverade aktörer har en viss kunskap och förståelse om de möjligheter och risker som finns för att kunna ta Sverige framåt mot en hållbar och cirkulär avloppshantering. Vidareutveckling av verktygen för att bättre kunna fånga upp de värden som är svåra att kvantifiera, eller sätta monetära värden på, behövs också.  Vägen framåt för en hållbar utveckling i framtidens Sverige kräver en tydlig förändring av samhällets hantering av resurser i avlopp. Inte bara krävs en attityd­förändring för att betrakta avlopp som resurs och inte avfall. Genom helhetstänk kan flera resurser samtidigt nyttjas och tillgodose samhällets behov och samtidigt hjälpa att bemöta olika utmaningar samhället står inför såsom exempelvis klimat­förändringen och annan negativ miljöpåverkan. En aktiv samverkan mellan olika myndigheter och andra aktörer krävs. Sveriges unika öppna arbetssätt, där erfaren-heter och kunskap som tas fram av en aktör, öppet delas med alla andra aktörer, utgör i detta sammanhang en enorm styrka som bör nyttjas genom ett brett nationellt samarbete. Ännu mer kunskap behöver tas fram eller syntetiseras för en effektivare implementering av de bästa lösningarna för en cirkulär resurshante­ring. Till sist kommer den omställningen som behövs inte kunna ske utan att det finns en tydlig samhällsinriktning som ger förutsättningar för aktörer att verka i. Här behöver incitament och styrmedel komma på plats i form av tydliga regelverk, uppdragsformulering, riktade utlysningar och eventuella ”fyrtornsprojekt” i natio­nell samverkan som skapar en kunskaps- och referensbas för implementering.

Kraft lignin is an underutilized resource from the pulp and paper industry with the potential of being a key raw material for renewable fuels and chemicals. The separation of high-molecular-weight lignin from black liquor by ultrafiltration has been widely investigated, while the permeate containing low-molecular-weight lignin has received little attention. Nanofiltration can concentrate the low-molecular-weight lignin. This work, therefore, evaluates nanofiltration for the separation and concentration of low-molecular-weight lignin from the ultrafiltration permeate. For this study, eight flat polymeric sheet membranes and one polymeric hollow fiber membrane, with molecular weight cut-offs ranging from 100 to 2000 Da, were tested. A parametric study was conducted at 50 °C, 2.5–35 bar, and crossflow velocity of 0.3–0.5 m/s. At a transmembrane pressure of 35 bar, the best performing membranes were NF090801, with 90% lignin retention and 37 L/m2·h, and SelRO MPF-36, with 84% lignin retention and 72 L/m2·h. The other membranes showed either very high lignin retention with a very low flux or a high flux with retention lower than 80%. Concentration studies were performed with the two selected membranes at conditions (A) 50 °C and 35 bar and (B) 70 °C and 15 bar. The NF090801 membrane had the highest flux and lignin retention during the concentration studies. Overall, it was shown that the nanofiltration process is able to produce a concentrated lignin fraction, which can be either used to produce valuable chemicals or used to make lignin oil.

The role of microalgae cultivation in wastewater treatment and reclamation has been studied extensively, as has the potential utility of the resulting algal biomass. Most methods for processing such biomass generate solid residues that must be properly managed to comply with current sustainable resource utilization requirements. Hydrothermal carbonization (HTC) can be used to process both individual wet feedstocks and mixed feedstocks (i.e., co-HTC). Here, we investigate co-HTC using microalgae and digested sewage sludge as feedstocks. The objectives were to (i) study the material’s partitioning into solid and liquid products, and (ii) characterize the products’ physicochemical properties. Co-HTC experiments were conducted at 180–250°C using mixed microalgae/sewage sludge feedstocks with the proportion of sewage sludge ranging from 0 to 100 %. Analyses of the hydrochar composition and the formation and composition of secondary char revealed that the content of carbonized material in the product decreased as the proportion of sewage sludge in the feedstock increased under fixed carbonization conditions. The properties of the hydrochars and the partitioning of material between the liquid phase and the hydrochar correlated linearly with the proportion of microalgae in mixed feedstocks, indicating that adding sewage sludge to microalgae had weak or non-existent synergistic effects on co-HTC outcomes. However, the proportion of sewage sludge in the feedstock did affect the secondary char. For example, adding sewage sludge reduced the abundance of carboxylic acids and ketones as well as the concentrations of higher molecular weight cholesterols. Such changes may alter the viable applications of the hydrochar. 

Carbon fibers (CFs) are gaining increasing importance in lightweight composites, but their high price and reliance on fossil-based raw materials stress the need for renewable and cost-efficient alternatives. Kraft lignin and cellulose are renewable macromolecules available in high quantities, making them interesting candidates for CF production. Dry-jet wet spun precursor fibers (PFs) from a 70/30 w/w blend of softwood kraft lignin (SKL) and fully bleached softwood kraft pulp (KP) were converted into CFs under fixation. The focus was to investigate the effect of carbonization temperature and time on the CF structure and properties. Reducing the carbonization time from 708 to 24 min had no significant impact on the tensile properties. Increasing the carbonization temperature from 600 to 800 °C resulted in a large increase in the carbon content and tensile properties, suggesting that this is a critical region during carbonization of SKL:KP PFs. The highest Young's modulus (77 GPa) was obtained after carbonization at 1600 °C, explained by the gradual transition from amorphous to nanocrystalline graphite observed by Raman spectroscopy. On the other hand, the highest tensile strength (1050 MPa) was achieved at 1000 °C, a decrease being observed thereafter, which may be explained by an increase in radial heterogeneity.

Det finns idag önskemål om att kvalitetssortera redan före torkning. För att kunna göra det måste man veta kur kvaliteten på virket påverkas av mellanlagring mellan såghus och torkhus samt av torkningsprocessen. I detta examensarbete har man studerat vilken inverkan mellanlagringen har på den relativa spricklängden före och efter torkning.

Seafood has an important role to play to achieve a sustainable food system that provides healthy food to a growing world population. Future seafood production will be increasingly reliant on aquaculture where feed innovation is essential to reduce environmental impacts and minimize feed and food competition. This study aimed to investigate whether a novel single cell protein feed ingredient based on Paecilomyces variotii grown on a side stream from the forest industry could improve environmental sustainability of farmed rainbow trout (Oncorhynchus mykiss) by replacing the soy protein concentrate used today. A Life Cycle Assessment including commonly addressed impacts but also the rarely assessed biodiversity impacts was performed. Furthermore, feeding trials were included for potential effects on fish growth, i.e., an assessment of the environmental impacts for the functional unit ‘kg feed required to produce 1 kg live-weight rainbow trout’. Results showed that the best experimental diet containing P. variotii performed 16–73 % better than the control diet containing soy protein concentrate in all impact categories except for energy demand (21 % higher impact). The largest environmental benefits from replacing soy protein with P. variotii in rainbow trout diets was a 73 % reduction of impact on biodiversity and halved greenhouse gas emissions. The findings have high relevance for the aquaculture industry as the production scale and feed composition was comparable to commercial operations and because the effect on fish growth from inclusion of the novel ingredient in a complete diet was evaluated. The results on biodiversity loss from land use change and exploitation through fishing suggest that fishery can dominate impacts and exclusion thereof can greatly underestimate biodiversity impact. Finally, a novel feed ingredient grown on side streams from the forest industry has potential to add to food security through decreasing the dependence on increasingly scarce agricultural land resources. 

Liquefaction of lignocellulosic biomass through fast pyrolysis, to yield fast pyrolysis bio-oil (FPBO), is a technique that has been extensively researched in the quest for finding alternatives to fossil feedstocks to produce fuels, chemicals, etc. Properties such as high oxygen content, acidity, and poor storage stability greatly limit the direct use of this bio-oil. Furthermore, high coking tendencies make upgrading of the FPBO by hydrodeoxygenation in fixed-bed bed hydrotreaters challenging due to plugging and catalyst deactivation. This study investigates a novel two-step hydroprocessing concept; a continuous slurry-based process using a dispersed NiMo-catalyst, followed by a fixed bed process using a supported NiMo-catalyst. The oil product from the slurry-process, having a reduced oxygen content (15 wt%) compared to the FPBO and a comparatively low coking tendency (TGA residue of 1.4 wt%), was successfully processed in the downstream fixed bed process for 58 h without any noticeable decrease in catalyst activity, or increase in pressure drop. The overall process resulted in a 29 wt% yield of deoxygenated oil product (0.5 wt% oxygen) from FPBO with an overall carbon recovery of 68%.

Co-refining of fast pyrolysis bio-oil together with fossil oil in existing refinery infrastructure is an attractive and cost-efficient route to conversion of lignocellulosic biomass to transportation fuel. However, due to large differences in properties between the two oils, special notice is needed to reduce process-related issues. Here, fast pyrolysis bio-oil produced from lignocellulosic biomass was co-refined with vacuum gas oil at a 20:80 weight ratio in continuous operation in a pilot-scale slurry hydrocracker in order to investigate the impact of process parameters on product quality and process performance. Mass balances together with product characterization were used to investigate product yields, product composition, and hydrodeoxygenation. Best conversion and hydrodeoxygenation of the fast pyrolysis bio-oil was achieved using an unsupported catalyst loading of 900 ppm Mo with either a low temperature (410 °C) and long residence time (2 h) or higher temperature (435 °C) and shorter residence time (1 h). These settings resulted in about 94% hydrodeoxygenation but also led to highest yield of biogenic carbon to gas phase (40-43 wt %) and lowest yield of biogenic carbon to oil fractions (53-56 wt %) as well as the water fraction (3-5 wt %). Successfully, coke yield remained low at around 0.07-0.10 wt % for all performed runs, which was comparable to the insoluble particle content in the feed due to the presence of particles in the untreated fast pyrolysis bio-oil. Co-processing pyrolysis oil with fossil oil in a slurry hydrocracker seems to be a robust process with regard to coke formation, which should lead to reduced plugging issues compared to fixed bed hydrotreaters. Although this study gives a brief understanding of the effect of process parameters on the processing of fast pyrolysis bio-oil, further research is required to find optimal process parameters and to fully comprehend the possibilities and limitations for production of transportation fuels from fast pyrolysis bio-oil using this technology.

Kraft lignin is an abundantly available and largely underutilized renewable material with potential for production of biobased fuels and chemicals. This study reports the results of a series of slurry hydroprocessing experiments with the aim of converting solid Kraft lignin to liquid products suitable for downstream refining in more conventional reactors. Experiments reported in this study were conducted by feeding a lignin slurry to an already hot, liquid-filled reactor to provide momentaneous heating of the lignin to the reaction temperature. This modified batch procedure provided superior results compared to the regular batch experiments, likely since unwanted repolymerization and condensation reactions of the lignin during the heating phase was avoided, and was therefore used for most of the experiments reported. Experiments were performed using both an unsupported Mo-sulfide catalyst and Fe-based catalysts (bauxite and hematite) at varied reaction temperatures, pressures, and catalyst loadings. The use of Mo-sulfide (0.1% Mo of the entire feed mass) at 425 °C and 50 bar resulted in complete conversion of the Kraft lignin to nonsolid products. Very high conversions (>95%) could also be achieved with both sulfided bauxite or hematite at the same temperature and pressure, but this required much higher catalyst loadings (6.25% bauxite or 4.3% hematite of the total feed mass), and around 99% conversion could be achieved at higher temperatures but at the expense of much higher gas yields. Although requiring much higher loadings, the results in this study suggest that comparatively nonexpensive Fe-based catalysts may be an attractive alternative for a slurry-based process aimed at the hydroconversion of solid lignin to liquid products. Possible implementation strategies for a slurry-based hydroconversion process are proposed and discussed. © 2022 The Authors.

Integration of renewable raw materials in existing refineries is most likely the shortest way for the successful, large-scale introduction of biofuels in the transport sector in the short term and medium term. One possible renewable raw material for this application is fast pyrolysis bio-oil (FPBO), which in this study has been coprocessed (at 0 and 20 wt %) with vacuum residue (VR, 50 wt %) and vacuum gas oil (VGO, balance) in a continuous, as well as a semibatch, slurry hydrocracking process. Experiments both with and without FPBO were performed at 450°C and 150 bar with a continuous hydrogen flow through the reactor. Oil-soluble molybdenum hexacarbonyl and molybdenum 2-ethylhexanoate were used as catalyst precursors, to be sulfided in situ. The continuous trials resulted in reactor walls completely free of coking, and they resulted in a low overall coke yield (about 1 wt %). The hydrodeoxygenation reached almost 92%, and the total acid number was reduced by nearly 99% in the FPBO experiment A mass balance of the renewable carbon from FPBO, based on the performed experiments, showed that the fossil CO2 emissions can be lowered by 1.35 kg per kg of processed FPBO if all renewable carbon in gaseous and liquid hydrocarbons is used to replace its fossil counterparts, and all methane formed from FPBO is used to produce hydrogen. Semibatch experiments gave less successful results when upgrading FPBO-containing feedstock, with a high coke yield (8 wt %) as well as a high gas yield (24 wt %). The results of this study demonstrate that FPBO can be successfully coprocessed with heavy fossil oils in a continuous slurry hydrocracking process without neg. affecting the processing of the fossil components of the feed and that a continuous process is preferred over batch or semibatch processes when studying coprocessing of bio-oils.

The aim of this study is to present the design, optimization and modelling of a chemical recovery system for a novel CS2-free viscose-type process that entails dissolution of pre-treated dissolving pulp in a continuous-flow reactor in cold alkali and wet spinning of cellulose in sodium carbonate solutions. Technologies already known to other industries for the recovery and reuse of chemicals, such as causticizing, recalcination, recarbonization and freeze-separation, were used. Chemical equilibria simulations were performed with OLI Studio 9.5, with the purpose to select experimental conditions which avoid undesired precipitations in each unit operation. Synthetic solutions mimicking the spent coagulation liquor were used in the laboratorial experiments. The proposed chemical recovery system was shown to be technically feasible and reduce chemical make-ups to a minimum of 45 kg/ton of NaOH and 4 kg/ton of H2SO4. Small amounts of Zn are expected to precipitate during recarbonization of the coagulation liquor at 30 °C and causticizing at 98 °C. Thus, a filter for ZnO particles should be included in the design of the recarbonization unit and a continuous purge of lime mud and input of fresh lime make-up should be needed to keep burnt lime availability at an acceptable level. Overall, the results presented in this study portray a solution to reduce operating costs and the environmental impact of novel viscose-type processes with alkaline spin dopes and wet spinning of cellulose in sodium carbonate solutions. © 2020, The Author(s).

Upscaling lignin-based precursor fibre production is an essential step in developing bio-based carbon fibre from renewable feedstock. The main challenge in upscaling of lignin fibre production by melt spinning is its melt behaviour and rheological properties, which differ from common synthetic polymers used in melt spinning. Here, a new approach in melt spinning of lignin, using a spin carrier system for producing bicomponent fibres, has been introduced. An ethanol extracted lignin fraction from LignoBoost process of commercial softwood kraft black liquor was used as feedstock. After additional heat treatment, melt spinning was performed in a pilot-scale spinning unit. For the first time, biodegradable polyvinyl alcohol (PVA) was used as a spin carrier to enable the spinning of lignin by improving the required melt strength. PVA-sheath/lignin-core bicomponent fibres were manufactured. Afterwards, PVA was dissolved by washing with water. Pure lignin fibres were stabilized and carbonized, and tensile properties were measured. The measured properties, tensile modulus of 81.1 ± 3.1 GPa and tensile strength of 1039 ± 197 MPa, are higher than the majority of lignin-based carbon fibres reported in the literature. This new approach can significantly improve the melt spinning of lignin and solve problems related to poor spinnability of lignin and results in the production of high-quality lignin-based carbon fibres. This article is part of the theme issue 'Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 2)'. © 2021 The Author(s).

The potential of producing biogas by digestion from substrates in Västra Götaland, Halland and Skåne has in this study been estimated to approximately 5 900 GWh per year, of which 2 300 GWh are found in Västra Götaland, 650 GWh in Halland and 3 000 GWh in Skåne. The estimated potential is based on the current amounts of the substrate categories food waste, agricultural residues, manure, sludge from sewage treatment plants and industrial organic residues. For each of the three regions, the largest contributor to the current substrate potential is agricultural residues. This category contributes with approximately 3 900 GWh annually in total for the three regions. However, to be able to fully realize the potential of the agricultural residues there are logistic and technical challenges to be solved. Manure accounts for the second largest contribution to the potential, approximately 1 000 GWh per year for the three regions. The conditions to realize the manure potential are good with national production support in place for this substrate category.

The study also includes a brief investigation of future substrate categories focused on marine substrates, grass and hay harvesting, industrial wastewater and biological methanation. From the future substrates, a contribution of a total of 3 600 GWh per year will be added to the estimated potential for the three regions. The largest addition is potential biological methanation of the carbon dioxide streams from the total substrate potential from the current categories, approximately 3 000 GWh annually. Thereafter, the largest contributing future substrate category is industrial wastewater. Including the future substrate flows, a total biogas potential of 9 500 GWh per year was estimated for Västra Götaland, Skåne and Halland together. To realize the potential, close cooperation between substrate owners, gas producers and municipalities are needed together as well as a long-term policy landscape.

Impregnation with high initial concentration is fast and efficient, leading to a homogeneous delignification in the subsequent cook, resulting in improved screened pulp yield. To obtain high initial alkali concentration, the white liquor flow needs to be significantly increased. The moisture content of the wood chips and the alkali concentration of the white liquor limit the initial alkali concentration of the impregnation liquor that can be reached. It is therefore of interest to evaluate the possibility to implement high alkali impregnation (HAI) industrially and the consequences this would have on the mill system. The effect of HAI on mass and energy balances in a kraft pulp mill has been studied using mill model simulations. The sensitivity to disturbances in important parameters for process control has been compared to impregnation scenarios used industrially. It was shown that high initial alkali concentration can be achieved on industrial scale by increased white liquor flow. HAI has a positive effect on recovery flows and reduces the need for make-up chemicals. The HAI concept is less sensitive to variations in process parameters, such as chip moisture and white liquor concentration, thus diminishing the risk of alkali depletion in chip cores.

A round robin study evaluating the analysis of biomass liquefaction oils (BLOs) from fast pyrolysis and hydrothermal liquefaction (HTL) was performed, receiving data from 14 laboratories in seven countries in order to assess the current status of analytical techniques for the determination of nitrogen, sulfur, and chlorine content in BLOs and to evaluate potential differences in origin (i.e., fast pyrolysis versus HTL). The BLOs were produced from a range of feedstocks including pine, mixed softwoods, forest residues, microalgae, miscanthus, and wheat straw to cover a variety in nitrogen, sulfur, and chlorine content and speciation. Nine samples were distributed, comprised of eight separate BLOs and one blind duplicate produced by five producers. The samples were analyzed for water, carbon, hydrogen, nitrogen, sulfur, and chlorine content. No analytical test method was mandated; laboratories were encouraged to utilize whichever method they determined would be most applicable, relying on the existing body of BLO literature as a guide. The results of this round robin study are presented in this paper. The results of the carbon, hydrogen, and water measurements as reference analyses had relative standard deviations (2.9, 3.5, and 5.6%, respectively) that were comparable to those found in past round robin studies on fast pyrolysis bio-oil. The analysis of nitrogen, sulfur, and chlorine showed higher levels of variability. Laboratories mostly chose the same method for water, carbon, hydrogen, and nitrogen determination, whereas there were a variety of methods chosen for sulfur and chlorine determination. The results suggest that specific analytical methods for the determination of nitrogen, sulfur, and chlorine should be further refined to ensure reproducible and accurate results for BLO analysis due to their importance in emissions, material selection, and catalyst activity.

Large amounts of cellulose-based waste textiles are generated every year, yet little is done to recycle this waste. Alternatives such as fiber-to-fiber recycling, where a significant part of the value of the waste textiles is recovered, are attractive possibilities. In this study, we have investigated the viability of using hydrated zinc chloride (ZnCl2·4H2O) as a solvent and swelling agent to convert cotton waste textiles (the most abundant cellulose-based waste textile) into a dissolving pulp that can be used as raw material for the production and spinning of viscose fibers. The solvent produced an accessible dissolving pulp and exhibited excellent recyclability, maintaining good dissolving power even after repeated recycling. The dissolving pulp was subsequently used to produce viscose dope, a spinning solution which was spun and cut into viscose staple fibers. The viscose dope exhibited good properties (moderate filter clogging value and gamma number), and the resulting staple fibers were strong and of good quality (high linear density, elongation, and tenacity). These results illustrate the potential of using hydrated zinc chloride for the production of viscose grade dissolving pulp from cotton waste textiles. 

The effect of reaction variables on the oxidative ammonolysis of technical lignins was studied in the range of 0.4-0.8 M NH4OH, reaction temperature of 70 - 130°C, oxygen pressure of 0.5 - 1.2 MPa and pH 9- 12.7. The kinetics of nitrogen incorporation consists of two phases, both of which follow a pseudo-first order reaction law. The reaction is 1st and 0.5 order with respect to oxygen and NH4OH concentration, respectively. The effective activation energy of nitrogen incorporation is rather low, 33-43 kJ/mol. The dependence of the reaction rate on pH of the reaction solution goes through a maximum. Linear correlation between nitrogen incorporation and O-demethylation, CO2 formation, oxygen uptake as well as oxygen incorporation were observed. Structural analyses of the soluble N-modified lignins by FTIR and 1H NMR spectroscopic techniques showed only qualitative differences of the spectra obtained under different reaction conditions indicating that the reaction conditions do not affect the reaction pathways. A scheme of possible reaction mechanisms is postulated based on the experimental results. 

Microbial community development within an anaerobic trickle bed reactor (TBR) during methanation of syngas (56% H2, 30% CO, 14% CO2) was investigated using three different nutrient media: defined nutrient medium (241 days), diluted digestate from a thermophilic co-digestion plant operating with food waste (200 days) and reject water from dewatered digested sewage sludge at a wastewater treatment plant (220 days). Different TBR operating periods showed slightly different performance that was not clearly linked to the nutrient medium, as all proved suitable for the methanation process. During operation, maximum syngas load was 5.33 L per L packed bed volume (pbv) & day and methane (CH4) production was 1.26 L CH4/Lpbv/d. Microbial community analysis with Illumina Miseq targeting 16S rDNA revealed high relative abundance (20–40%) of several potential syngas and acetate consumers within the genera Sporomusa, Spirochaetaceae, Rikenellaceae and Acetobacterium during the process. These were the dominant taxa except in a period with high flow rate of digestate from the food waste plant. The dominant methanogen in all periods was a member of the genus Methanobacterium, while Methanosarcina was also observed in the carrier community. As in reactor effluent, the dominant bacterial genus in the carrier was Sporomusa. These results show that syngas methanation in TBR can proceed well with different nutrient sources, including undefined medium of different origins. Moreover, the dominant syngas community remained the same over time even when non-sterilised digestates were used as nutrient medium. Key points: •Independent of nutrient source, syngas methanation above 1 L/Lpbv/D was achieved. •Methanobacterium and Sporomusa were dominant genera throughout the process. •Acetate conversion proceeded via both methanogenesis and syntrophic acetate oxidation. Graphical abstract: [Figure not available: see fulltext.] © 2022, The Author(s).

Test facility for prefabricated storm water treatment devices.

In Sweden, stormwater management has usually implied release of stormwater into the nearest recipient with no concern for either the levels of contaminants in the water or to the sensitivity of the recipient. The demand for sustainable solutions has increased along with more knowledge concerning stormwater toxicity and the harmful effects it can have on the environment in the long term. New technical solutions for stormwater treatment are continuously being presented on the market, however, independent third-party tests have rarely been conducted to verify the function of these solutions. To choose the right technology for a specific application while ensuring the function over an extended period of time, can therefore be complex task for customers. Likewise, the variety of requirements on treatment efficiency makes in challenging for technology suppliers as there is currently no possibility of independent testing of stormwater treatment devices in Sweden to verify this. As a step towards a more sustainable stormwater management, RISE developed a proposal for a national standard for prefabricated treatment devices within a Vinnova-funded project in 2019. Subsequently, the Swedish Environmental Protection Agency has financed three follow-up projects where this is the latter of the three. The aim for this project has been to answer the remaining questions and create sufficient knowledge to be able to build the test bed in a next step. During the project, a lot of valuable information has been gathered through interviews, dialogues, a workshop and a survey with actors from both the customer side and the supplier side in Sweden and internationally. The design of the test bed has emerged and is based on the proposed standard and the input that has come along the project. A business model has been developed, where different alternatives have been studied. Based on this, ways forward have been discussed. The conclusions of the project can be summarized by the fact that the need for a clearer definition of requirements for stormwater quality and a national standard for third-party tests of stormwater treatment devices is great both from customers and technology suppliers. Based on the dialogues conducted with international actors, it has emerged that several countries (e.g., Germany and the UK) have come further than Sweden in this area and there is much to be gained from continuing the dialogue and cooperate further on these issues. The business model shows that a mobile facility is preferable, as the area of use can then be broadened and revenues for rent can supplement income from standardized tests. However, this means that only smaller facilities can be evaluated in the facility, which several technology providers have been critical of. One possibility that have been discussed within the project is that larger facilities could be evaluated according to a Swedish standard at an established test bed abroad. For standardized tests, the cost estimate is SEK 200,000 towards the customer, to also get coverage for inactive periods. If the investment cost of the test bed can be financed in another way, for example through national grants, depreciation costs are reduced by approximately SEK 10,000 / week, which contributes to reduced costs per test and rental period. This would give more technology providers the opportunity to perform tests, as well as enable an expanded knowledge building, which would benefit the industry as a whole.

There are operating parameters that affect the hydrogen formation from APC-residues generated in waste fired CFB-boilers. There are also reasons to be careful and take extra consideration to safety aspects in environments where the APC-residue has been exposed to water. It is well known that if the APC-residues generated from waste fired CFB-boilers are exposed to water; hydrogen gas is formed. The overall aim of the project has been to decrease the work environment hazards related to hydrogen formation from these APC-residues. Another aim has also been to increase the general knowledge related to these hydrogen related hazards. This has been accomplished by exploring which operating parameters and general mechanisms that affect the hydrogen formation from the APC-residues. Both total amount of gas formed as well as the velocity of the gas formation has been of interest. The APC-residues used in this project have been from P14 and P15 at the waste-to-energy plant Händelöverket, owned and operated by E.ON. In literature there are almost no publications on the hydrogen gas formation from APC residues generated by waste fired CFB boilers. There are some related to waste fired grate boilers though. Conclusions and theories from literature data must be put together from results regarding similar materials in totally different environments. The experimental results indicate a difference in the hydrogen formation from APCresidues originating from P14 and P15. The bed material used in the boilers is also one of the operational parameters that seems to affect the reactivity of the APCresidue. The introduction of a share of Ilmenite in the bed material seems to have lowered the amount of hydrogen gas formed, alternatively it delayed the formation. Other operational conditions that was considered was a decreased thermal load, lowered amount of ammonia added to reduce NOx, and storage/aging of ash in the NID-reactor while it was not running on full capacity. There are indications that these conditions also affect the reactivity, however there are too few data available to make specific conclusions. In general, it seems difficult to control the reactivity of the APC-residue while keeping normal production in the plant. In fouling samples, from different parts of the boilers, levels of metallic aluminium fully comparable to those in the APC-residue were detected. Thus, there is a significant risk of hydrogen formation when using wet cleaning methods during maintenance stops. Proper ventilation and education are two of the recommendations to mitigate the risks. A potential logistic chain for APC-residues, based on ship transports, was risk assessed. Since the hydrogen formation differs greatly between different ash deliveries, an important conclusion was that it is hazardous to generalise the results, especially by using average hydrogen formation rates. Another conclusion was that consideration must be made for the fact that the hydrogen formation might be delayed and might not arise until the APC-residue is treated mechanically

It has recently been shown that pore condensation and freezing (PCF) is a mechanism responsible for ice formation under cirrus cloud conditions. PCF is defined as the condensation of liquid water in narrow capillaries below water saturation due to the inverse Kelvin effect, followed by either heterogeneous or homogeneous nucleation depending on the temperature regime and presence of an ice-nucleating active site. By using sol-gel synthesized silica with well-defined pore diameters, morphology and distinct chemical surface-functionalization, the role of the water-silica contact angle and pore width on PCF is investigated. We find that for the pore diameters (2.2-9.2 nm) and water contact angles (15-78<span classCombining double low line"inline-formula">ĝ</span>) covered in this study, our results reveal that the water contact angle plays an important role in predicting the humidity required for pore filling, while the pore diameter determines the ability of pore water to freeze. For <span classCombining double low line"inline-formula"><i>T</i>>235</span> K and below water saturation, pore diameters and water contact angles were not able to predict the freezing ability of the particles, suggesting an absence of active sites; thus ice nucleation did not proceed via a PCF mechanism. Rather, the ice-nucleating ability of the particles depended solely on chemical functionalization. Therefore, parameterizations for the ice-nucleating abilities of particles in cirrus conditions should differ from parameterizations at mixed-phase clouds conditions. Our results support PCF as the atmospherically relevant ice nucleation mechanism below water saturation when porous surfaces are encountered in the troposphere. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.

Adequate treatment of organic manures and digestates from livestock production should reduce environmental impacts and provide well-defined and attractive biofertlisers for a crop production market, which can promote the closure of the nutrient cycle in agriculture. In this sense, a survey was conducted during the autumn of 2021 to investigate Swedish farmers’ perspectives on organic fertilisers use. The survey consisted of an online questionnaire, which was distributed broadly in the social media, homepages, different types of networks and at course events in order to reach all types of farms. There were 22 questions focused on current use, reasons for current use and preferences for future use. The analysis of the 99 fully responded surveys, demonstrated that 43% of the respondents think that they will increase their use of organic fertilisers in the coming 5–10 years and 60% think that they will use manure digestate in different forms (both solid and liquid fractions). Soil improvement was the main reason to use organic fertilisers, but there were also preferences for organic fertilisers with fast release of nutrients. The risk of soil compaction was the main reason not to use organic fertilisers and based on the responses, pellets and granulates seem to be more interesting than liquids and solids in general. Animal manures dominate the current use of organic fertilisers in Sweden however, other types of organic waste such as digestate and digestate derived fertilisers seems appealing to Swedish farmers. In conclusion, from this survey with 62% of the respondees in crop production, we found several indications of that there is a potential for increased use of organic fertilisers in Sweden on farms with limited use today. We found an openness, a broad interest and a demand for different types of products of different forms and origin. Since this demand in the end will almost always depend on the price of products in relation to the price of mineral fertilisers, which are fluctuating, we see the need of policy incentives in order to stimulate initiatives for the development towards increased circularity of nutrients. 

This study conducted a life cycle assessment (LCA) of manure management, identifying transportation as a major contributor to global warming and freshwater eutrophication impacts. Transporting substrates to the biogas plant was the main hotspot, highlighting a critical area for improvement. The findings emphasize the importance of method selection in geographically dependent assessments, especially in the Baltic Sea region. Characterization factors specific to Sweden revealed higher environmental impact values than those produced by the ReCiPe method, underscoring the need for regional differentiation in LCA. By optimizing manure management practices and enhancing nutrient distribution, impacts on both climate change and eutrophication can be significantly reduced, thereby lowering nutrient flow to the Baltic Sea. Combining these optimizations with transportation impact reductions further amplifies these environmental benefits, demonstrating that geographically tailored approaches in LCA offer essential insights for managing regional-scale effects. 

Paper grade pulp production across the globe is dominated by the kraft process using different lig-nocellulosic raw materials. Delignification is achieved around 90% using different chemical treatments. A bottleneck for complete delignification is the presence of residual covalent bonds that prevail between lignin and carbohydrate even after severe chemical pulping and oxygen delignification steps. Different covalent bonds are present in native wood that sustain drastic pulping conditions. In this study, 100% birch wood was used for producing paper grade pulp, and the lignin carbohydrate bonds were analyzed at different stages of the kraft cook. The lignin carbohydrate bonds that were responsible for residual lignin retention in unbleached pulp were compared and analyzed with the original lignin-carbohydrate complex (LCC) bonds in native birch wood. It was shown that lignin remaining after pulping and oxygen delignification was mainly bound to xylan, whereas the lignin bound to glucomannan was for the most part degraded. Application: One central problem for the pulp and paper industry is efficiency in delignification during the chemical pulping and bleaching processes. It has been believed that one limiting factor is the covalent bonds between lignin and polysaccharides. We present data on presence of such LCC bonds in paper grade birch pulp and its development during the processes. Hopefully, this research data will be useful for the development of more effi-cient processes. 

Reducing the use of fossil fuels is an ongoing and important effort considering the environmental impact and depletion of fossil-based resources. The combination of ablative fast pyrolysis and hydroprocessing is explored as a pathway allowing bio-based intermediates (BioMates) integration in underlying petroleum refineries. The proposed technology is validated in industrially relevant scale, identifying pros and cons towards its commercialization. Straw from wheat, rye and barley was fed to ablative fast pyrolysis rendering Fast Pyrolysis Bio-Oil (FPBO) as the main product. The FPBO was stabilized via slurry hydroprocessing, rendering a stabilized FPBO (sFPBO) with 49 % reduced oxygen content, 71 % reduced carbonyl content and 49 % reduced Conradson carbon residue. Fixed bed catalytic hydroprocessing of sFPBO resulted in the production of BioMates, a high bio-content product to be co-fed in established refinery units. Compared to the starting biomass, BioMates has 83.6 wt% C content increase, 92.5 wt% O content decrease, 93.0 wt% water content decrease, while the overall technology has 20 wt% conversion yield (32 wt% carbon yield) from biomass to BioMates. © 2022 The Author(s)

The discovery of lytic polysaccharide monooxygenases (LPMOs) as a cellulase component has brought a significant revolution to the enzymatic degradation of lignocellulosic biomass. LPMOs are powerful oxidative enzymes which can cleave glycosidic bonds in polysaccharides, such as starch, cellulose, xylan and chitin. The mechanism of action and analysis of LPMOs is complex due to which its discovery has been delayed even though its other counterparts as cellulase components have been known for some time. Their significance in biomass hydrolysis is presented in this chapter along with details of the mechanism of action and determination methods associated with complexities and future avenues. The addition of LPMOs can further reduce cellulase cost in enzyme cocktails of enzyme manufacturers, which has increased the rate of hydrolysis by more than twofold. 

The Adrar region (Algeria) has a total of 397,800 date palm trees (Phoenix dactylifera L.). Due to annual palm cleaning, large quantities of lignocellulosic biomass are produced. Depending on the variety, an average of 65 kg of biowaste is obtained per palm tree. Since the value of this biowaste is underrated, most of the palms are burned outdoors, causing air and visual pollution. This work explores the gasification potential of lignocellulosic waste from date palms (Phoenix dactylifera L. Takarbouche variety) into useful energy. The technology investigated is air updraft fixed-bed gasification, thanks to an originally designed and built reactor, with the capability to process 1 kg of feedstock. Four types of palm waste—namely, palms, petioles, bunch, and bunch peduncles—are first characterized (bulk density, proximate analysis, fixed carbon, elemental composition, and calorific value) and then used as feedstock for two gasification tests each. The syngas produced for the four date palm wastes is combustible, with an outlet temperature between 200 and 400 °C. The operating temperature inside the gasifier varies according to the feature of the biomass cuts (from 174 °C for the peduncles to 557 °C for palms). The experimental setup is also equipped with a cyclone, allowing for the recovery of some of the tar produced during the tests. Finally, the results show that the residence time has a positive effect on the conversion rate of date palm waste, which can significantly increase it to values of around 95%. 

Trees constitute promising renewable feedstocks for biorefinery using biochemical conversion, but their recalcitrance restricts their attractiveness for the industry. To obtain trees with reduced recalcitrance, large-scale genetic engineering experiments were performed in hybrid aspen blindly targeting genes expressed during wood formation and 32 lines representing seven constructs were selected for characterization in the field. Here we report phenotypes of five-year old trees considering 49 traits related to growth and wood properties. The best performing construct considering growth and glucose yield in saccharification with acid pretreatment had suppressed expression of the gene encoding an uncharacterized 2-oxoglutarate-dependent dioxygenase (2OGD). It showed minor changes in wood chemistry but increased nanoporosity and glucose conversion. Suppressed levels of SUCROSE SYNTHASE, (SuSy), CINNAMATE 4-HYDROXYLASE (C4H) and increased levels of GTPase activating protein for ADP-ribosylation factor ZAC led to significant growth reductions and anatomical abnormalities. However, C4H and SuSy constructs greatly improved glucose yields in saccharification without and with pretreatment, respectively. Traits associated with high glucose yields were different for saccharification with and without pretreatment. While carbohydrates, phenolics and tension wood contents positively impacted the yields without pretreatment and growth, lignin content and S/G ratio were negative factors, the yields with pretreatment positively correlated with S lignin and negatively with carbohydrate contents. The genotypes with high glucose yields had increased nanoporosity and mGlcA/Xyl ratio, and some had shorter polymers extractable with subcritical water compared to wild-type. The pilot-scale industrial-like pretreatment of best-performing 2OGD construct confirmed its superior sugar yields, supporting our strategy. © 2023 The Authors. 

Blue Economy is seen as an essential contributor to a sustainable development, and it is an important part of the EU Green Deal. Seaweed plays a key role in the Blue Economy as a source of food, feed, and feedstock for biorefineries. Today, the largest part of global seaweed production is based in Asia, but there is also a growing interest in seaweed production in Europe. However, more knowledge on the environmental impacts is needed to ensure sustainable growth of the sector. Seaweed can be used in biorefineries to produce a variety of products for food and non-food applications. The aim of this paper was to perform a life cycle assessment (LCA) of a seaweed value-chain, including seaweed cultivation and production into sodium alginate, biodegradable materials, biogas, and fertilizer in a biorefinery setting. The LCA included 19 environmental impact categories but focused on climate change. The seaweed Saccharina latissima was cultivated and processed in Ireland. Sodium alginate was then extracted by means of ultrasound-assisted extraction, a novel extraction technology. Cellulosic residues produced after the extraction were used for the production of films used as a packaging material. Residues that remain after the production of the films were sent to anaerobic digestion to achieve a no-waste concept. For seaweed cultivation, fuel use and drying of seaweed biomass were the main environmental hot spots; and for the alginate extraction process, the yield and purification after extraction were the main hot spots. Overall, the results of this paper showed that the seaweed-based biorefinery has the potential to be sustainable, but several improvements are necessary before it is competitive with land-based systems. © 2022 The Authors

The agricultural industry plays a crucial role in transitioning towards a sustainable and fossil-free future. This article explores the potential of biorefineries using biomass from agriculture to reduce emissions and promote self sufficiency. Regarding a concept that integrated anaerobic digestion, grass and legume protein production, and hydrothermal liquefaction. A case study was conducted in the southwestern part of Sweden, involving interviews with a biogas plant and local farmers. The study analyzed the utilization of input goods in agriculture and evaluated the potential of biomass in the area. To assess the potential for farms to become self-sufficient in fuel, protein feed, and plant nutrients. The results show an overall positive outlook of the biorefinery concept. By utilizing 20% of the available biomass in the area can the biorefinery concept annually produce 100 GWh of biogas, 3800 tonnes of grass and legume protein concentrate and 1200 GWh bio-oil. This could theoretically cover 100 % of the need of soy meal, 44% for nitrogen, 50% for phosphorus and 100% for potassium.

This paper reports the first Computational Fluid Dynamics (CFD) model developed for biomass pyrolysis oil spray combustion using Finite-Rate Chemistry (FRC) approach. To make the CFD calculations feasible, a reduced mechanism for modeling the combustion of biomass Fast Pyrolysis Oil (FPO) based on the POLIMI 1412 mechanism and a model for eugenol oxidation was developed. The reduced mechanism consisted of 200 reactions and 71 species. This level of complexity was found to be a good tradeoff between predictive power and computational cost such that the reduced model could be used in CFD modeling. The predictive power of the reduced mechanism was demonstrated via 0D (adiabatic, premixed, constant pressure reactor), 1D (laminar counterflow flame) and 3D (CFD of a methane-air flat-flame piloted FPO spray flame) calculations. Results from CFD were compared against experimental data from non-intrusive optical diagnostics. The reduced model was successfully used in CFD calculations—the computational cost was approximately 2 orders of magnitude higher than that of a simplified model. Using the reduced mechanism, the concentration of pollutants, minor combustion products, and flame radicals could be predicted—this is added capability compared to already existing models. The CFD model using the reduced mechanism showed quantitative predictive power for major combustion products, flame temperature, some pollutants and temperature, and qualitative predictive power for flame radicals and soot. © 2021 The Authors

Industrial thermal plasma torches can heat a gas up to 5000–20,000 K, i.e., well above the temperature needed to replace the heat generated from the combustion of traditional fossil fuels (e.g., coal, oil, and natural gas) in large-scale process industry furnaces producing construction materials (e.g., iron, steel, lime, and cement). However, there is a risk for significant NOx emissions when air or N2 are used as plasma-forming gas since the temperature somewhere in the furnace always will be higher compared to the threshold NOx formation temperature of ∼1800 K. Torch NOx forms inside the high temperature region of the plasma torch (>5000 K) when air is used as gas. Process NOx forms instead when the hot gas (when air or nitrogen is used as plasma forming gas) from the plasma torch mixes with process air downstream the torch. By analysing the complex chemistry of both the torch- and process NOx formation with thermodynamic equilibrium and one-dimensional chemical kinetic calculations it was shown that adding H2 to the plasma-forming N2 gas significantly reduces the NOx emissions with more than 90 %. Verifying experiments with air, pure N2, and mixtures of H2 and N2 as plasma-forming gas were performed in a laboratory scale insulated laboratory furnace with different pre-heating temperatures of process air (293, 673, and 1073 K) which the plasma gas mixes with downstream the torch. Depending on the pre-heating temperature the NOx emissions were between 12,000–14,000 mg NO2/MJfuel when air was used as plasma forming gas. Substantial NOx emission reduction occurs both when N2 replaces air, where the NOx emissions was in the span of 8000–11,500 mg NO2/MJfuel and furthermore when H2 was mixed into the N2 gas stream. For the highest degree of H2 mixing (28.6 vol-%), the NOx emissions were between 450–1700 mg NO2/MJfuel depending on the pre-heat temperature of the process air, i.e., a reduction of 88–96 % and 85–94 %, respectively when air or N2 was used as plasma forming gas. The measured NOx emissions are then of the same order of magnitude as would be expected from the combustion of traditional fuels (coal, oil, biomass and pure H2). Finally, by analysing the aerodynamics in an axisymmetric furnace with an experimentally validated computational fluid dynamics (CFD) model using reduced chemistry for the NOx formation (19 species and 70 reactions), further guidelines into the process of NOx reduction from thermal plasma torches are given. 

Adaptive Laboratory Evolution (ALE) of microorganisms can improve the efficiency of sustainable industrial processes important to the global economy. However, stochasticity and genetic background effects often lead to suboptimal outcomes during laboratory evolution. Here we report an ALE platform to circumvent these shortcomings through parallelized clonal evolution at an unprecedented scale. Using this platform, we evolved 104 yeast populations in parallel from many strains for eight desired wine fermentation-related traits. Expansions of both ALE replicates and lineage numbers broadened the evolutionary search spectrum leading to improved wine yeasts unencumbered by unwanted side effects. At the genomic level, evolutionary gains in metabolic characteristics often coincided with distinct chromosome amplifications and the emergence of side-effect syndromes that were characteristic of each selection niche. Several high-performing ALE strains exhibited desired wine fermentation kinetics when tested in larger liquid cultures, supporting their suitability for application. More broadly, our high-throughput ALE platform opens opportunities for rapid optimization of microbes which otherwise could take many years to accomplish.

An important factor in the development of sodium-ion batteries (SIBs) is the use of cheap and sustainable materials. Sodium lignosulfonate, a lignin derivative, is demonstrated here as an attractive, "green", water-soluble, and potentially cost-effective binder for use in hard carbon anodes for SIBs. A comparison of its battery cycling performance is made against other binders including sodium carboxymethyl cellulose and lignin, obtained from the kraft process, as well as sodium alginate, derived from algae. Apart from lignin, which requires processing in N-methyl-2-pyrrolidone, the other three binders are water-soluble. Lignosulfonate shows comparable or better performance, with high capacity retention and stability, when using 1 M NaPF6 in propylene carbonate or ethylene carbonate:diethyl carbonate electrolytes for both half- and full-cells (against a Prussian white cathode). Further improvements are observed when including styrene-butadiene rubber as a co-binder. X-ray photoelectron spectroscopy demonstrates similar solid electrolyte interphase compositions after the initial sodium insertion for both lignosulfonate and carboxymethyl cellulose binders. However, after subsequent cycling, the surface layer composition and thickness are found to be dependent on the binder. For the lignosulfonate-based electrode, the layer appears thicker but comprises a smaller fraction of carbon-oxygen species. © 2021 The Authors.

Avoiding snow on photovoltaic (PV) installations is motivated for two reasons: to decrease power losses from shading, or to decrease mechanical loads to avoid damage to the PV-installation and the underlying construction. We experimentally investigated the effectiveness and suitability of four different snow removal methods at our facility in the north of Sweden (Piteå, 65°N), throughout three winters. The layout of a PV installation and the underlying roof, together with meteorological conditions and snow characteristics, impact which methods are best suited for snow removal. A simple roof rake with a rectangular toolhead works well when the snowpack is compact and not too thick, whereas a roof rake with a slide works better when the snow is dry and packed. Neither the investigated passive hydrophobic surface coatings, nor the active forward bias electrical heating methods induced shedding of the accumulated snowpack in our experiments without additional intervention. At our test facility in Piteå, the roof rake with a slide was the most effective and user-friendly snow removal. Despite maximum snow loads of approximately 1 kPa, far below the modules’ rating, cell damage was observed for both snow removal groups (except for the slide roof rake group) and the control group.

Different conditions such as module orientation, ground albedo, shading and latitude are known to affect the performance of bifacial photovoltaic modules. We evaluate bifacial performance for one year at a site located at 65°N through comparison of measured and simulated front and back side plane-of-array irradiation. Each investigated module has a different azimuth, tilt, and exposure to shading from the surroundings. Local shading is found to severely impact the energy yield of the site in general, and individual modules to a varying degree depending on their location and orientation. Proper shading analysis appears to be required in the planning phase of a bifacial photovoltaic installation to accurately calculate the expected energy yield. The bifacial gain of the modules with azimuths in the east–west sector is found to span a range from 16 % to approximately the bifaciality factor, depending on the orientation. To fully utilize the potential of bifacial photovoltaics, this variability also needs to be carefully considered when planning and building bifacial photovoltaic installations.

Waste electrical and electronic equipment (WEEE) has become a critical environmental problem. Catalytic pyrolysis is an ideal technique to treat and convert the plastic fraction of WEEE into chemicals and fuels. Unfortunately, research using real WEEE remains relatively limited. Furthermore, the complexity of WEEE complicates the analysis of its pyrolytic kinetics. This study applied the Fraser-Suzuki mathematical deconvolution method to obtain the pseudo reactions of the thermal degradation of two types of WEEE, using four different catalysts (Al2O3, HBeta, HZSM-5, and TiO2) or without a catalyst. The main contributor(s) to each pseudo reaction were identified by comparing them with the pyrolysis results of the pure plastics in WEEE. The nth order model was then applied to estimate the kinetic parameters of the obtained pseudo reactions. In the low-grade electronics pyrolysis, the pseudo-1 reaction using TiO2 as a catalyst achieved the lowest activation energy of 92.10 kJ/mol, while the pseudo-2 reaction using HZSM-5 resulted in the lowest activation energy of 101.35 kJ/mol among the four catalytic cases. For medium-grade electronics, pseudo-3 and pseudo-4 were the main reactions for thermal degradation, with HZSM-5 and TiO2 yielding the lowest pyrolytic activation energies of 75.24 and 226.39 kJ/mol, respectively. This effort will play a crucial role in comprehending the pyrolysis kinetic mechanism of WEEE and propelling this technology toward a brighter future.