Simultaneous hydrogen and ethanol production in a thermophilic AFBR: a comparative approach between cellulosic hydrolysate single fermentation and the fermentation of glucose and xylose as co-substrates

Author(s)

Santos Lopes, Helberth Junnior ^[1] ; Ramos, Lucas Rodrigues ^[1] ; de Menezes, Camila Aparecida ^[2] ; Silva, Edson Luiz ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Chem Engn, Rod Washington Luis, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Sao Paulo, Dept Hydraul & Sanitat, Av Trabalhador Saocarlense 400, BR-13566590 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Cellulose; v. 27, n. 5 JAN 2020.
• Web of Science Citations: 0

Abstract

This study evaluated the effect of hydraulic retention time (HRT) on the simultaneous hydrogen and ethanol production in two anaerobic fluidized bed reactors (55 degrees C) from mono-fermentation of cellulosic hydrolysate (AFBR-C) and the fermentation of glucose and xylose as co-substrates (AFBR-GX). In AFBR-C, the HRT was decreased from 24 to 8 h, while in AFBR-GX, the HRT was decreased from 16 to 0.5 h. The carbohydrate concentration was maintained at 4 g/L (AFBR-GX) and 2 g/L (AFBR-C). In AFBR-C, the main results observed by decreasing the HRT from 24 to 8 h were the increase in H-2 yield (0.6-1.1 mol H-2/mol hexose) and ethanol concentration (0.02-0.48 g/L). However, the H-2 yield in AFBR-GX decreased from 0.4 to 0.1 mol H-2/mol hexose by decreasing the HRT from 16 to 0.5 h. Additionally, the shortest HRTs applied to the AFBR-C (8 h) and AFBR-GX (0.5 h) resulted in the maximum hydrogen production rates of 115.7 and 279.9 mL H-2/h L, the maximum energy yields of 7.4 and 47.7 kJ/h L, and EtOH molar fractions of 58.9 and 50.2%, respectively. {[}GRAPHICS] . (AU)

• FAPESP's process: 15/06246-7 - Biorefinery concept applied to biological wastewater treatment plants: environmental pollution control coupled with material and energy recovery
• Grantee: Marcelo Zaiat
• Support Opportunities: Research Projects - Thematic Grants