The use of brewer’s spent grain after beer production for energy purposes

Abstract

The aim of this study was to assess the possibilities to use brewer’s spent grains le over from beer production for energy purposes, and to determine its calorific value and chemical composition.The research material were samples of wet spent grain from a brewery in Poland. Three samples, which di ered in ingredient composition, were examined. The examined samples of brewer’s spent grains were characterized by humidity typical for this product (approx. 77 - 80 %). Convective drying of the spent grain samples at five temperatures of the drying medium contributed to lowering water content in biomass, and the final moisture was below 10%. The samples of dry spent grain being examined contained a similar amount of ash (3.8 - 4.1 %) and organic matter (91.0 - 91.9 %). All the examined spent grain samples demonstrated similar volatile matter content – approx. 77.8 - 78.7 % and calorific value – approx. 15.6 - 15.9 MJ/ kg. The estimated calorific value for wet samples (approx. 1.4 - 2.0 MJ/kg) indicates that it is necessary to lower water content in the biomass in order to improve its energy properties.