Hydrothermal processing of agar waste to levulinic acid and fermentation of hydrolysate to bioethanol.
Bioresour Technol
; 382: 129063, 2023 Aug.
Article
em En
| MEDLINE
| ID: mdl-37080439
ABSTRACT
Increasing global energy consumption and depleting fossil-fuel reserves prompted the search for green alternatives. This study focuses on conversion of waste agar using different acids/alkalis (0.5% and 1%) as catalysts under varied temperature and time towards galactose (Gal), 5-hydroxymethylfurfural (HMF) and levulinic acid (LA) production in sequential reactions. The optimized process for agar depolymerisation was achieved using 1% acid (H2SO4/HCl) catalysed conditions with a maximum of 11 g/L Gal yield (121 °C; 15 min). Increase in temperature (150 °C) and time (180 min) with 1% HCl/H2SO4 catalyst resulted in improved LA production along with Gal and HMF. The hydrolysis process was optimised for the selective production of LA (10 g/L at 175 °C; 180 min). Further, galactose-rich hydrolysates were assessed for bioethanol production using Saccharomyces cerevisiae that resulted in 3 g/L ethanol. Thus, the study comprehensively demonstrates waste agar utilization to yield biochemicals/fuels in a circular bio-based economy approach.
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1
Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
/
Galactose
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article