Microwave-assisted pretreatment of maize distillery stillage with the use of dilute sulfuric acid in the production of cellulosic ethanol.

Affiliation

Kazimierz Wielki University, Department of Biotechnology, 85-671 Bydgoszcz, ul. K. J. Poniatowskiego 12, Poland. Electronic address: [Email]

Abstract

This study aimed to evaluate the effectiveness of microwave-assisted pretreatment in production of cellulosic bioethanol from maize distillery stillage. High glucose concentration (104.4 ± 0.4 mg/g dry weight) and the highest yield of enzymatic cellulose hydrolysis (75.8 ± 0.9%) were obtained for microwave pretreatment characterized by the following parameters: 300 W, 54 PSI, 15 min. Such pre-treatment parameters allowed the obtaining of not only a high concentration of glucose, but also a low concentration of fermentation inhibitors, i.e. 5-hydroxymethylfurfural (6.8 ± 0.4 mg/g of DW) and furfural (6.0 ± 1.2 mg/g dry weight). Optimal dose of yeast, Saccharomyces cerevisiae strain Ethanol Red which gave a high attenuation was 2 g/L of cellulose fermentation medium. Detoxification of cellulose hydrolysates with activated carbon enabled achieving high fermentation yield (approximately 77% of the theoretical yield). Microwave processing can be an effective pretreatment method in production of cellulosic ethanol from maize distillery stillage, but this process requires careful selection of parameters.

Keywords

Cellulosic ethanol,Maize distillery stillage,Microwave-assisted pretreatment,