Improved ethanol production from organic waste by wet oxidation pre-treatment

The feasibility of efficient ethanol production from the cellulose fraction of municipal solid waste (MSW) and woody yard waste by means of simultaneous saccharification and fermentation (SSF) by Saccharomyces cerevisae was investigated after (thermal) wet oxidation pre-treatment. The effects of varying wet oxidation parameters (e.g. temperature ( https://www.w3.org/1998/Math/MathML" display="inline"> 185 - 200 ∘ C ), pH and oxygen pressure ( https://www.w3.org/1998/Math/MathML" display="inline"> 3 - 12 bar)) on the enzymatic cellulose and hemicellulose degradation of the organic waste were evaluated. The SSF procedure at https://www.w3.org/1998/Math/MathML" display="inline"> 10 % dry matter (DM) revealed cellulose to ethanol conversion efficiencies ranging from https://www.w3.org/1998/Math/MathML" display="inline"> 50 - 70 % for MSW and https://www.w3.org/1998/Math/MathML" display="inline"> 40 - 79 % for yard waste at cellulase loadings varying from 5–25 FPU (filter paper units)/g DM, corresponding to 22 and https://www.w3.org/1998/Math/MathML" display="inline"> 24 g / 1 ethanol for the highest enzyme loading. At moderate enzyme loadings ( https://www.w3.org/1998/Math/MathML" display="inline"> 1 5 F P U / g DM), the ethanol yield was https://www.w3.org/1998/Math/MathML" display="inline"> 65 % and https://www.w3.org/1998/Math/MathML" display="inline"> 69 % of the theoretical yield for MSW and yard waste respectively. The wet oxidized filtrates did not exhibit any toxicity to the yeast.