Characterization and Catalytic Upgrading of Crude Bio-oil Produced by Hydrothermal Liquefaction of Swine Manure and Pyrolysis of Biomass

The distillation curve of crude bio-oil from glycerol-assisted hydrothermal liquefaction of swine manure was measured using an advanced distillation apparatus. The crude bio-oil had much higher distillation temperatures than diesel and gasoline and was more distillable than the bio-oil produced by the traditional liquefaction of swine manure and the pyrolysis of corn stover. Each 10% volumetric fraction was analyzed from aspects of its chemical compositions, chemical and physical properties. The appearance of hydrocarbons in the distillates collected at the temperature of 410.9°C and above indicated that the thermal cracking at a temperature from 410°C to 500°C may be a proper approach to upgrade the crude bio-oil produced from the glycerol-assisted liquefaction of swine manure. The effects of thermal cracking conditions including reaction temperature (350-425°C), retention time (15-60 min) and catalyst loadings (0-10 wt%) on the yield and quality of the upgraded oil were analyzed. Under the optimum thermal cracking conditions at 400°C, a catalyst loading of 5% by mass and the reaction time of 30 min, the yield of bio-oil was 46.14% of the mass of the crude bio-oil and 62.5% of the energy stored in the crude bio-oil was recovered in the upgraded bio-oil. The upgraded bio-oil with a heating value of 41.4 MJ/kg and viscosity of 3.6 cP was comparable to commercial diesel.;In upgrading crude bio-oil from fast pyrolysis, converting organic acids into neutral esters is significant and can be achieved by sulfonated activated carbon/bio-char developed from fermentation residues. Acitivated carbon and bio-char were sulfonated by concentrated sulfuric acid at 150°C for 18 h. Sulfonation helped activated carbon/bio-char develop acid functional groups. Sulfonated activated carbon with BET surface area of 349.8 m2/g, was effective in converting acetic acid. Acetic acid can be effectively esterified by sulfonated activated carbon (5 wt%) at 78°C for 60 min with the ethanol to acetic acid ratio of 3.;Crude pyrolytic oil obtained from the RTI International had distillation temperatures from 164.8°C to 365.5°C and 50% volumetric fraction of the crude bio-oil was distillable. Esterified pyrolytic bio-oil had an increased distillability up to 55% volumetric fraction. The esterified pyrolytic bio-oil had an increased pH of 6.12. Diesel range pyrolytic bio-oil distilled from esterified pyrolytic bio-oil had quite comparable properties with commercial diesel, with an energy content of 41.41 MJ/kg, water content of 0.58 wt%, and viscosity of 7.45 cP.