Title:
Parameter Optimization for the Process of Enzymatic Hydrolysis
Author(s):
Zhang, W., Lin, Y., Wang, X., Ma, H., Peng, Z
Document(s):
Paper
Abstract:
Nowadays, the intense energy crisis as well as with the numerous environmental problems forced people to develop renewable energy resources to replace the fossil fuels. Bioethanol, especially produced from the lignocellulosic biomass, is most promising owing to its abundance all around the world and can avoid the severe problem of food crisis. However it is really difficult to produce ethanol directly from lignocellulosic biomass, and only the reducing sugars can be fermented to ethanol. In this paper, we focused on the processes of enzymatic hydrolysis and the crucial process of ethanol production. We carried out experiments to explore the most suitable circumstance in which the Sigma C2730 liquid cellulase could show the highest enzymatic hydrolysis efficiency. A series of experiments were conducted with the single factor method to optimize the enzymatic hydrolysis processes. Five parameters: reaction time, pH, temperature, substrate concentration and enzyme concentration were considered in the experiments.The cellulose and wheat straw were chosen to be the substrates to investigate the operation parameters in the study, and both the substrates were simply physically pretreated. Enzymatic activity of the enzyme preparation was 82.22FPU/ml, pH varied from 4.0¬6.0 , temperature from 30¬50°C and reaction time from 24¬96h. Results showed that the maximum hydrolysis was at 40°C with initial solids loading (cellulose and wheat straw) of 4% (w/v) and enzyme concentration of 15FPU/g dry substrate. The glucose recovery reached 56.32% after 72h and 35.82% after 96h when the substrates were cellulose and wheat straw respectively. The hydrolysis efficiency rose up at the temperature interval of 30¬40°C, and reached the peak value at 40°C then decreased with the temperature since the cellulase activity was inhibited at higher temperature. The pH 4.0 was observed to be the optimum value at which the glucose and xylose concentration were obtained16.82g/L and 2.17g/L respectively after 72h. In addition, the optimum condition for enzyme hydrolysis of wheat straw was pH4.0, reaction time 96h and temperature 40°C when the initial solids and enzyme loading (cellulose and wheat straw) were 4% (w/v) and 15FPU/g dry substrate respectively.
Keywords:
bioethanol, cellulose, enzymatic hydrolysis, lignocellulose, wheat straw, cellulase
Topic:
R&D on Processes for Solid, Liquid and Gaseous Fuels from Biomass
Subtopic:
Bioethanol production and sugar release from lignocellulosic
Event:
20th European Biomass Conference and Exhibition
Session:
3DV.1.14
Pages:
1632 - 1636
ISBN:
978-88-89407-54-7
Paper DOI:
10.5071/20thEUBCE2012-3DV.1.14
Price:
FREE
