Thesis
Effects of pretreatments on the yield and composition of bio-oil from the auger pyrolysis of woody biomass
Washington State University
Master of Science (MS), Washington State University
2010
Handle:
https://hdl.handle.net/2376/103550
Abstract
The effect of different pretreatments (hot water, thermal pretreatment and the use of additives: 0.3 mass % H2SO4 and 0.3 mass % NH4H2PO4) on the production of pyrolytic sugars (Levoglucosan and hydrolysable sugars) from Douglas fir and Hybrid Poplar were studied. Treated and untreated biomasses were characterized to understand the effect of pretreatment conditions on their overall chemical makeup. The thermal behavior and the pyrolysis activation energy for each of the untreated and pretreated samples were studied by Thermogravimetry. The use of NH4H2PO4 as additive significantly increases pyrolysis activation energy most likely due to the modification of lignin thermal degradation mechanism. Douglas fir samples (as received and after pretreatment) were pyrolysed in an Auger Pyrolysis Reactor and the yield of products was determined. The chemical composition of bio-oil produced was characterized by KF-titration, GC/MS, TG, Cold water precipitation and IEC. The use of H2SO4 as additive increased the bio-oil yield by 10 mass %. The other treatments do not have an important impact on oil yields. Although H2SO4 and NH4H2PO4 increases the content of levoglucosan in the oils by 6 and 4 mass % respectively, none of the pretreatments studied have any important effect on the content of total fermentable sugars. An important finding of this thesis is a reduction in the content of pyrolytic lignin in the oil by 6 and 12 mass % when using H2SO4 and NH4H2PO4 as additives. This finding suggests that these additives modify the thermal degradation of lignin and consequently its interactions with cellulose. The use of these additives may be recommended if the end use of the oil is to develop high value products from levoglucosan.
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Details
- Title
- Effects of pretreatments on the yield and composition of bio-oil from the auger pyrolysis of woody biomass
- Creators
- Das Oisik
- Contributors
- Manuel Garcia-Perez (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Systems Engineering, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525079801842
- Language
- English
- Resource Type
- Thesis