Ethanol production from brewers spent grains

Abstract

[Excerpt] The brewing industry generates large amounts of wastes and by-products that need to be treated, among of which, brewer’s spent grains (BSG - the residual solid material obtained after the wort elaboration) are the most abundant. Finding alternatives for the reuse of this byproduct is of great interest for economical and environmental reasons. The present study evaluated the use of BSG as raw material for ethanol production. BSG was supplied by Unicer brewery (Matosinhos, Portugal). Part of this material was initially submitted to an hydrothermal process (121 ºC; during 10 or 90 min) using a solid:liquid ratio of 1 g BSG/10 mL distilled water. Subsequently, the untreated and hydrothermal pretreated BSG were submitted to an acid hydrolysis reaction using a liquid:solid ratio of 10 g/g and 100 mg sulfuric acid/g dry matter, at 163 °C for 45 min. [...]