Thesis
Evaluation of pretreatment technologies for the simultaneous production of lipids and ethanol from lignocellulosic materials
Washington State University
Master of Science (MS), Washington State University
2010
Handle:
https://hdl.handle.net/2376/103105
Abstract
A new strategy to fully utilize cellulose and hemicellulose in lignocellulosic materials to produce lipids and ethanol was proposed and evaluated. This process involves three steps: (1) the lignocellulosic materials are pretreated by selective technologies (2) the solid residues mainly consisting of cellulose are subjected to simultaneous saccharification and fermentation (SSF) for ethanol production and (3) the hydrolysate generated during the pretreatment containing pentoses from the hemicellulose was converted into lipids by oleaginous yeasts. Our results showed that as the chemicals applied in the pretreatment, dilute sulfuric acid, sodium hydroxide and peracetic acid modified the substrates' physical and chemical structures specifically. The best pretreatment technologies identified: (a) the sodium hydroxide pretreatment for wheat straw and (b) the peracetic acid pretreatment for poplar wood achieved their maximum sugar yields of 603.4 mg/g initial dry biomass and 505.3 mg/g initial dry biomass for each substrate, respectively. The potential of the hydrolysate from diluted sulfuric acid pretreatment of wheat straw was evaluated for lipid production. And the experimental results indicated that all the tested strains (Cryptococcus curvatus, Rhodotorula glutinis, Rhodosporidium toruloides, Lipomyces starkeyi and Yarrowia lipolytica) could use detoxified hydrolysate. It was also found that non-detoxified hydrolysate could be used for the growth of all of the selective yeast strains except R. toruloides. C. curvatus had the best performance in regards to lipid concentrations in medium on both the detoxified (4.2 g/L) and non-detoxified (5.8 g/L) hydrolysates, respectively.
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Details
- Title
- Evaluation of pretreatment technologies for the simultaneous production of lipids and ethanol from lignocellulosic materials
- Creators
- Xiaochen Yu
- Contributors
- Shulin Chen (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, Wash. :
- Identifiers
- 99900525200101842
- Language
- English
- Resource Type
- Thesis