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Björkmalm, J., Byrne, E., van Niel, E. & Willquist, K. (2018). A non-linear model of hydrogen production by Caldicellulosiruptor saccharolyticus for diauxic-like consumption of lignocellulosic sugar mixtures. Biotechnology for Biofuels, 11, Article ID 175.
Open this publication in new window or tab >>A non-linear model of hydrogen production by Caldicellulosiruptor saccharolyticus for diauxic-like consumption of lignocellulosic sugar mixtures
2018 (English)In: Biotechnology for Biofuels, ISSN 1754-6834, E-ISSN 1754-6834, Vol. 11, article id 175Article in journal (Refereed) Published
Abstract [en]

Background

Caldicellulosiruptor saccharolyticus is an attractive hydrogen producer suitable for growth on various lignocellulosic substrates. The aim of this study was to quantify uptake of pentose and hexose monosaccharides in an industrial substrate and to present a kinetic growth model of C. saccharolyticus that includes sugar uptake on defined and industrial media. The model is based on Monod and Hill kinetics extended with gas-to-liquid mass transfer and a cybernetic approach to describe diauxic-like growth.

Results

Mathematical expressions were developed to describe hydrogen production by C. saccharolyticus consuming glucose, xylose, and arabinose. The model parameters were calibrated against batch fermentation data. The experimental data included four different cases: glucose, xylose, sugar mixture, and wheat straw hydrolysate (WSH) fermentations. The fermentations were performed without yeast extract. The substrate uptake rate of C. saccharolyticus on single sugar-defined media was higher on glucose compared to xylose. In contrast, in the defined sugar mixture and WSH, the pentoses were consumed faster than glucose. Subsequently, the cultures entered a lag phase when all pentoses were consumed after which glucose uptake rate increased. This phenomenon suggested a diauxic-like behavior as was deduced from the successive appearance of two peaks in the hydrogen and carbon dioxide productivity. The observation could be described with a modified diauxic model including a second enzyme system with a higher affinity for glucose being expressed when pentose saccharides are consumed. This behavior was more pronounced when WSH was used as substrate.

Conclusions

The previously observed co-consumption of glucose and pentoses with a preference for the latter was herein confirmed. However, once all pentoses were consumed, C. saccharolyticus most probably expressed another uptake system to account for the observed increased glucose uptake rate. This phenomenon could be quantitatively captured in a kinetic model of the entire diauxic-like growth process. Moreover, the observation indicates a regulation system that has fundamental research relevance, since pentose and glucose uptake in C. saccharolyticus has only been described with ABC transporters, whereas previously reported diauxic growth phenomena have been correlated mainly to PTS systems for sugar uptake.

Keywords
Caldicellulosiruptor saccharolyticus – Hydrogen – Kinetic growth model – Glucose uptake – Xylose uptake – Diauxic
National Category
Microbiology
Identifiers
urn:nbn:se:ri:diva-34067 (URN)10.1186/s13068-018-1171-3 (DOI)2-s2.0-85049011727 (Scopus ID)
Funder
Swedish Energy Agency, 31090-2
Available from: 2018-07-06 Created: 2018-07-06 Last updated: 2019-01-07Bibliographically approved
Xie, Y., Björkmalm, J., Ma, C., Willquist, K., Yngvesson, J., Wallberg, O. & Ji, X. (2018). Techno-economic evaluation of biogas upgrading using ionic liquids in comparison with industrially used technology in Scandinavian anaerobic digestion plants. Applied Energy, 227, 742-750
Open this publication in new window or tab >>Techno-economic evaluation of biogas upgrading using ionic liquids in comparison with industrially used technology in Scandinavian anaerobic digestion plants
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2018 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 227, p. 742-750Article in journal (Refereed) Published
Abstract [en]

The process of biogas upgrading with ionic liquids, i.e. pure 1-butyl-3-methylimidazolium bis(trifluoro-methylsulfonyl)imide ([bmim][Tf2N]), aqueous choline chloride/urea (ChCl/Urea), and aqueous 1-allyl-3-methyl imidazole formate ([Amim][HCOO]), was simulated in Aspen Plus and compared with the conventional water scrubbing upgrading technique. The comparisons of the performances on the amount of recirculated solvents and energy usage show the following order: aqueous [Amim][HCOO]<aqueous ChCl/Urea<[bmim][Tf2N]<water. Six different co-digestion plants (anaerobic digestion, AD, plants) were surveyed to acquire data for comparison. The selected plants had different raw biogas production capacities and produced gas with differing methane content. The data confirmed the simulation results that the type of substrate and the configuration of AD process are two factors affecting energy usage, investment cost, as well as operation and maintenance costs for the subsequent biogas upgrading. In addition, the simulation indicated that the energy usage of the ionic liquid-based upgrading was lower than that of the conventional upgrading techniques in Scandinavian AD plants. The estimated cost including investment, operation and maintenance for the ionic liquid technology showed to be lower than that for the water scrubbing upgrading process.

Keywords
Anaerobic digestion, Biogas upgrading, Ionic liquids, Process simulation, Techno-economic evaluation, Biogas, Computer software, Costs, Economic analysis, Energy utilization, Gas plants, Investments, Liquids, Choline chloride, Estimated costs, Investment costs, Ionic liquid technology, Operation and maintenance, Process simulations
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-31131 (URN)10.1016/j.apenergy.2017.07.067 (DOI)2-s2.0-85026290782 (Scopus ID)
Available from: 2017-08-28 Created: 2017-08-28 Last updated: 2019-07-01Bibliographically approved
Henriksson, G., Willquist, K., Björkmalm, J., Johansson, I., Hedenstedt, A. & Kjerstadius, H. (2015). Benchmarking av gödselsamrötning med avloppsslam mot förbränning av häst- och djurparksgödsel (ed.). Paper presented at .
Open this publication in new window or tab >>Benchmarking av gödselsamrötning med avloppsslam mot förbränning av häst- och djurparksgödsel
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2015 (Swedish)Report (Refereed)
Abstract [sv]

Owners of stables and owners of zoos have difficulty finding an economically sustainable deposition of their produced manure. More than two million tons of horse manure are produced in urban environments in Sweden every year. If the manure cannot be used as fertilizer on farm land it is classified as a waste fraction and should be handled according to current regulations. The manure is a valuable waste fraction that contains both energy and nutrients. If the manure cannot be spread on farm land more applications need to be identified, where the energy and nutrients in the manure can be used. The focus in this study is to investigate possible applications for the usage of horse and zoo manure within Borås municipality where, among other things, a waste water treatment plant and a combined heat and power plant are available. Horse and zoo manure have been investigated in the following applications: co-digestion with sewage sludge at a waste water treatment plant (lab experiments), co-digestion with food waste (theoretical), co-incineration with waste (full scale) and co-incineration with biomass (theoretical). Potential quantity of manure and economical and legal aspects have been studied as well. There is no compilation of the number of horses in the country which makes it hard to estimate the true quantity of manure. The quantity of manure from the zoos are somewhat easier to estimate since the zoo owners are fewer and have knowledge of their manure production. The co-digestions experiments in this study showed that addition of horse manure to digestion can be of interest in many ways, among other things it can give a more stable biogas production and a possible decrease in the Cd/P-ratio in the end product. Horse manure turned out to have a faster degradation rate compared to zoo manure, however the degradation rate was lower than that of sewage sludge. Zoo manure gave a relatively low biogas production compared to horse manure at thermophilic conditions. The co-incineration trial with waste and manure gave no negative effect with regard to emissions and operation. However, the amount of manure added to the incineration trial was low. The theoretical studies regarding the co-incineration with biomass, showed two potential alternatives that need to be investigated further. Interesting aspects to look further upon, based on this study, are for example: • Laws and regulations in the EU regarding manure. • Co-digestion of manure and sewage sludge in a larger scale. • Laws and regulations and costs regarding incineration of manure with biomass.

Series
SP Rapport, ISSN 0284-5172 ; 2015:11
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-5243 (URN)20373 (Local ID)978-91-88001-41-2 (ISBN)20373 (Archive number)20373 (OAI)
Available from: 2016-09-07 Created: 2016-09-07 Last updated: 2018-08-17Bibliographically approved
Willquist, K., Björkmalm, J., Sjöstrand, K., Lagerkvist, A., Erixon, R., Johansson, B., . . . Liu, J. (2015). Biological treatment toolbox for Swedish mine drainage (ed.). Paper presented at .
Open this publication in new window or tab >>Biological treatment toolbox for Swedish mine drainage
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2015 (English)Report (Refereed)
Publisher
p. 76
Series
SP Rapport, ISSN 0284-5172 ; 2015:18
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-5250 (URN)20479 (Local ID)978-91-88001-48-1 (ISBN)20479 (Archive number)20479 (OAI)
Available from: 2016-09-07 Created: 2016-09-07 Last updated: 2019-06-20Bibliographically approved
Johansson, I., Sahlin, E., von Bahr, B., Björkmalm, J. & Todorovic Olsson, J. (2014). Kritiska metaller i Svenska avfallsaskor (ed.). Paper presented at .
Open this publication in new window or tab >>Kritiska metaller i Svenska avfallsaskor
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2014 (Swedish)Report (Refereed)
Series
WR56.
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-5603 (URN)16286 (Local ID)16286 (Archive number)16286 (OAI)
Available from: 2016-09-08 Created: 2016-09-08 Last updated: 2018-08-17Bibliographically approved
Johansson, I., Sahlin, E., von Bahr, B., Björkmalm, J. & Todorovic Olsson, J. (2014). Kritiska metaller i Svenska avfallsaskor (ed.). Paper presented at .
Open this publication in new window or tab >>Kritiska metaller i Svenska avfallsaskor
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2014 (Swedish)Report (Refereed)
Series
Avfall Sverige E2014:02.
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-5604 (URN)16287 (Local ID)16287 (Archive number)16287 (OAI)
Available from: 2016-09-08 Created: 2016-09-08 Last updated: 2018-08-17Bibliographically approved
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-5758-4137

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