Bioethanol production from acid pretreated microalgal hydrolysate using microwave-assisted heating wet torrefaction
Document Type
Article
Publication Date
1-1-2020
Abstract
This study focused on the bioethanol production from the co-production of solid biochar and liquid hydrolysate under microwave-assisted heating wet torrefaction towards a sustainable green technology. The two indigenous microalgal biomass undergone dilute acid pretreatment using wet torrefaction to produce microalgal hydrolysates and biochar at operating conditions of 160–170 °C with holding times of 5–10 min. The hydrolysates were utilized for fermentation with the yeast Saccharomyces cerevisiae at 29 °C in a dark condition at a non-agitation state for 120 h. The concentrations of total reducing sugar, reducing sugar by-product, and bioethanol in the hydrolysates were determined. The carbohydrate-rich microalga C. vulgaris ESP-31 showed a good performance in bioethanol production. Microalgal hydrolysate obtained after the pretreatment consisted of a total reducing sugar with the highest concentration of 98.11 g/L. The formation of by-product 5-hydroxymethyl-2-furaldehyde (5-HMF), which might act as the fermentation inhibitor that led to the low ethanol yield, was also analyzed. The highest ethanol yield achieved was 7.61% with a maximum experimental conversion probability of 95.22%. This study has demonstrated the feasible bioethanol production from microalgal hydrolysate through microwave-assisted heating wet torrefaction using dilute acids and the optimization of bioethanol production can be carried out for better performance in the future study. © 2020 Elsevier Ltd
Keywords
Bioethanol and biochar, Wet torrefaction, Microalgae, Hydrolysate, Acid hydrolysis, Alternative fuel
Divisions
InstituteofBiologicalSciences
Funders
University of Malaya , Malaysia under the SATU Joint Research Scheme with the grant number of ST023-2019 and partnership grant with National Cheng Kung University (NCKU), Taiwan, under the grant number of RK002-2019,Higher Education Sprout Project, Ministry of Education to the Headquarters of University Advancement , Taiwan at NCKU,Ministry of Science and Technology, Taiwan , R.O.C., under grant numbers of MOST 106-2923-E-006-002-MY3 and MOST 109-3116-F-006-016-CC1
Publication Title
Fuel
Volume
279
Publisher
Elsevier