Production of Bio-Diesel Additives from Dairy Manure in Supercritical Ethanol

Production of Bio-diesel Additives from Dairy Manure in Supercritical Ethanol

Xiaokun Yang¹, Mi Lu¹, Marcus Vinicius Pereira¹, Simon Poulson³, Charles Coronella¹, and Hongfei Lin^1*

¹Chemical Engineering and Materials Science Department, ²Agriculture, Biotechnology & Natural Resources Department, ³Geological Sciences & Engineering Department,

University of Nevada, Reno, NV, U.S 89557

E-Mail: HongfeiL@unr.edu

Dairy manure is regarded as a waste material that needs substantial waste management. However, as the biomass feedstock it contains lipid, protein, lignin, hemicellulose, and cellulose, which can be used to produce value-added chemicals. Herein, dried dairy manure was converted in ethanol and ethanol-water solutions at near supercritical conditions. The highest conversion of manure reached to 72% (ash free) under supercritical ethanol at 245°C. In the presence of solid Lewis acid catalysts, Zr-KIT-6 or hydrated niobia, ethyl esters from cellulose, hemicellulose and lignin were the main products, which can be used as biodiesel additives. It was found that adding 5-10 % water in ethanol enhanced the decomposition of recalcitrant cellulose and lignin, and thus increased the manure conversion and the overall yields of ethyl esters. Various process conditions including temperature, pressure, biomass-to-catalyst ratio, water-to-ethanol ratio, etc. were examined and optimized. High-loading amounts of manure were used in this process which makes the catalytic process promising for future's scale-up to industrial scale. Lastly, the possible reaction mechanism based on Lewis acid catalysis in supercritical ethanol-water solvents was discussed.