New Pretreatment methods for lignocellulosic residue for second generation bioethanol production | |
| Author | Guragain, Yadhu Nath |
| Call Number | AIT Thesis no.FB-10-30 |
| Subject(s) | Ethanol as fuel Fermentation Lignocellulose |
| Note | A thesis submitted in partial fulfillment of the re quirements for the degree of Master of Science in Food Engineering and Bioprocess Technology, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. no.FB-10-30 |
| Abstract | Bioethanol is being projected in many countries as a sustainable alternative to gasoline to mitigate the global problem of fuel crisis and to reduce the greenhouse gas emissions. In order to avoid the competition with food, the use o f abundantly available and non edible parts of plants, including fast-growing aquatic plants and agricultural waste, as feedstock is being attempted. However, the commercial production of ethanol using such lignocellulosic residue is still not economically viable. One of the major bottlenecks in this process is pretreatment of biomass for the breakdown of cellulose-hemicelluloses-lignin complex. Therefore, the development of efficient, cost effective and environmentally friendly pretreatment method is important. In this study, some emerging pretreatment methods, namely the use of crude glycerol, ionic liquids and extrusion cooking, were evaluated by comparing their effectiveness with dilute acid pretreatment, using wheat straw and water hyacinth as feedstocks. Hydrolysis yield of glucose and total reducing sugar, using cellulase enzyme from Trichoderma reesei, and fermentation yield of ethanol, using Saccharomyces cerevisiae, were taken as the measure of the effectiveness of these pretreatment methods. This study showed that 1-butyl-3-methylimidazolium acetate (an ionic liquid) pretreatment is the best method for the pretreatment of wheat st raw. The hydrolysis yield of glucose and total reducing sugar in this method was found 2.1 a nd 3.3 times respectively more than dilute acid pretreatment, while fermentation inhibi tion was not noticeable. However, if the existing cost of ionic liquids and byproduct utiliz ation of biodiesel industry are taken into consideration; crude glycerol pretreatment could be a better method. This is because the yield of glucose and total reducing sugar was 1.4 a nd 1.9 times respectively more than dilute acid pretreatment in this method. Similarly , for the pretreatment of water hyacinth, crude glycerol pretreatment was found as effective as dilute acid pretreatment and more effective than ionic liquid pretreatment. Moreover, crude glycerol was found as effective as pure glycerol (purity 99%) for the pretreatment of both feedstocks. This opens an opportunity for novel utilization of crude glycerol , which is a major byproduct of the biodiesel industry |
| Year | 2010 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. no.FB-10-30 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Food Engineering and Bioprocess Technology (FB) |
| Chairperson(s) | Rakshit, Sudip Kumar;Durand, Alian; |
| Examination Committee(s) | Athapol Noomhorm;Anal, Anil k.; |
| Scholarship Donor(s) | World Bank (JJ/WBGSP);Asian Institute of Technology Fellowship; |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2010 |