Comparison of bioethanol production from corn and tapioca starch by conventional and raw starch hydrolysis processes | |
| Author | Sarocha Pradyawong |
| Call Number | AIT Thesis no.FB-13-08 |
| Subject(s) | Cassava Corn Ethanol as fuel |
| Note | A thesis submitted in partial fulfillment of the requirements 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-13-08 |
| Abstract | Nowadays, bioethanol is produced form variety of feedstocks. Corn is the major source of bioethanol in the most successful ethanol production in the USA. On the other hand, tapioca is the high potential feedstock in the South East Asia. In a conventional process, dextrin is hydrolyzed from starch high temperatures (90–120 °C) during liquefaction process with liquefaction enzymes. Then, saccharification enzymes hydrolyzed dextrin a simultaneous saccharification and fermentation (SSF) process. Recently, a StargenTM002, new raw starch hydrolyzing enzyme (RSH), was developed. It has ability to convert starch into dextrin and sugars at low temperatures (48 °C) and also breakdown dextrin into sugars during SSF process. Therefore, this research aimed to study the comparison of ethanol production on different types of corn, and tapioca starch. The study is focused on two processes, Raw Starch Hydrolysis (RSH) process using new enzymes, StargenTM 002 and conventional process using Spezyme® CL and Distillase®SSF enzyme. For the conventional process, the liquefaction enzyme Spezyme® CL was applied at 85 °C and pH 5.7 on a 25% solid content. On the other hand, StargenTM 002 was functional at 48 °C and pH 4.2 in RSH process. The concentrations of 15% and 25% solid content were applied to the wet milled corn starch in both processes. The 25% solid content conditions provided more concentrate ethanol than that of 15% solid content condition. Wet milled dent corn starch with conventional process at 25% solid content provided the significantly highest ethanol concentration of 18.19±0.04% (v/v) or 14.35±0.03% (w/v). The modified (cross-linked) version of dent corn and tapioca starch were studied in both processes at 25% solid content by comparing with the unmodified versions. Both 2 types of modified starch showed significantly less ethanol concentration in both processes. The initial fermentation rates (at 2-6 hours) of RSH process in most conditions were higher than those of conventional process due to higher glucose concentration in RSH process at the SSF step. On the other hand, conventional process resulted in different types of sugars (glucose, maltose, maltotriose and DP4+) than RSH process. The ethanol production from 4 types of laboratory grade starch, dent, waxy and high amylose corn and tapioca starch, at 25% solid content were compared in both processes. In Raw Starch Hydrolysis (RSH) process, the lower temperature method, was effective in ethanol production. No significantly difference in ethanol amount was observed in laboratory grade waxy corn and tapioca starch of both processes. The high amylose corn laboratory grade starch resulted in significantly lowest ethanol concentration in both processes. The significantly highest ethanol concentration of16.88±0.29% (v/v) or 13.32±0.23% (w/v) was observed in laboratory grade dent corn starch with conventional process. On the other hand, the highest ethanol concentration of RSH process was 16.21±0.22% (v/v), which was not significantly different from the dent corn with conventional process, presented in laboratory grade tapioca starch. Therefore, Raw Starch Hydrolysis (RSH) process is an interesting, effective and suitable method and can be used instead of the conventional process in Thailand and South East Asia due to abundant availability of cassava. |
| Year | 2013 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. no.FB-13-08 |
| 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) | Thapol Noomhorm; |
| Examination Committee(s) | Singh, Vijay;Anal, Anil Kumar;Muanmai Apintanapong; |
| Scholarship Donor(s) | Royal Thai Government; |
| Degree | Thesis (M. Sc.) - Asian Institute of Technology, 2013 |