Sequential hydrothermal liquefaction of oleaginous microalgae Chlorella sorokiniana to simultaneously extract value added polysaccharides and a bio-oil rich in free fatty acids
Washington State University
Master of Science (MS), Washington State University
2012
:
https://hdl.handle.net/2376/101693
A sequential hydrothermal liquefaction (SEQHTL) process for the efficient extraction of bio-oil and polysaccharide from wet algal biomass was developed. The SEQHTL process developed simultaneously separates value-added polysaccharides and bio-oil from algal biomass by two temperature gradient steps. The effects of reaction temperature, residence time, and biomass/water ratio on products distribution for each step were investigated. Maximum yield (32 wt %) of value-added polysaccharides was obtained when the first HTL step was conducted at 160°C, 20 min and 1:9 biomass/water ratio. Maximum bio-oil yields (>30%) in the second step were obtained when it was operated at 240°C, 20 min and 1:9 biomass/water ratio. Product yield of the second SEQHTL step was compared with single step direct hydrothermal liquefaction (DHTL). The oils produced by SEQHTL and DHTL were characterized by GC, GC-MS, NMR, and FT-IR analysis. The bio-oil extracted by both approaches did not show significant differences. With the increase of temperature in bio-oil production reaction, the yield of fatty acid decreased for both SEQHTL and DHTL. The energy recovery rate, energy input, net energy balance, and thermal efficiency for SEQHTL and DHTL were estimated and compared. In spite of having two steps, SEQHTL showed better thermal efficiency than DHTL. The concept proposed demonstrated to be an important step towards the concomitant production of value added co-products and bio-oil from algal biomass.
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- Sequential hydrothermal liquefaction of oleaginous microalgae Chlorella sorokiniana to simultaneously extract value added polysaccharides and a bio-oil rich in free fatty acids
- Chao Miao
- Shulin Chen (Degree Supervisor)
- Washington State University
- Biological Systems Engineering, Department of
- Master of Science (MS), Washington State University
- Washington State University; Pullman, Wash. :
- 99900525170701842
- English
- Thesis