Evaluation of degradation tendency of wood polymeric compounds in wood extract at high temperature
2015 (English)In: 18th International Symposium on Wood, Fiber and Pulping Chemistry, September 9-11, 2015, Vienna, 2015, 382-384 p.Conference paper (Other academic)
This study aims to find out the effect of exposure time and process conditions on changes of the wood extract from hot water extraction, when it is exposed at high temperature after the extraction. This information is needed, when an intensified process combining extraction and separation is designed for recovery of hemicelluloses, because in a process of this kind theextract is exposed to high temperature also after the extraction step.The study was done with two different extract batches. The extract 1 was produced at 140 oC (circulation time 2 hours) and the extract 2 at 160 oC (circulation time 1.5 hours). Samples of these extracts were exposed to 120 oC and 160 oC for different timeperiods between 15 and 285 minutes (0.25-4.75 hours).Based on this study it seems that processing of the extract at high temperature would likely to be safe at 120 oC for several hours, while at 160 oC no longer than 2-3 hours processing times can be recommended. The 4 hours exposure to 120 oC caused a clear decrease (20-30%) only in lignin amount (based on UV absorbance) but hemicellulose, monosaccharide and solid concentrations were not significantly affected. The five hours exposure to 160 oC caused remarkable hemicellulose losses (%). In addition, significant changes could be observed in lignin and solids content of the extracts.
Place, publisher, year, edition, pages
2015. 382-384 p.
degradation, hemicellulose, extraction, hot water, molecular structure, biomass, lignin, wood, polymer
Paper, Pulp and Fiber Technology
IdentifiersURN: urn:nbn:se:ri:diva-29127OAI: oai:DiVA.org:ri-29127DiVA: diva2:1083096
18th International Symposium on Wood, Fiber and Pulping Chemistry, September 9-11, 2015, Vienna