Bio-oil and bio-char from low temperature pyrolysis of spent grains using activated alumina

► This study examines the pyrolysis of spent grains from bio-ethanol production using activated alumina sand. ► The spent grains were densified and partially deoxygenated by pyrolysis. ► The biochar resulted very attractive as a soil amendment and for carbon sequestration. ► The bio-oil from spent grains could meet about 9% of the renewable obligation in the UK.