Study on preparation of new solid fuel and its combustion performance from bio-oil and waste cooking oil mixture via vacuum distillation

The mixture of bio-oil and waste cooking oil with long carbon-chain was used to produce bio-coal via vacuum distillation, so as to improve its physicochemical properties especially its combustion performance as a new solid fuel. The effect of ratio of meat or vegetable oil represented by lard and soybean oil in the mixture (L-Oil and SOil) on the physical and chemical properties of bio-coal was studied emphatically. The results revealed that the bio-coal obtained via vacuum distillation of bio-oil mixed with 40 % S-oil (SBC) including more carbon content and fatty acid presented better physicochemical properties than that of bio-coal obtained by mixing L-oil (LBC) with higher carbon content (82.74 %) and calorific value (34.19 MJ/kg) basically similar to that of the commercial coal. The above bio-coal and anthracite were mixed to investigate their combustion characteristics. The TG analysis revealed that there is a synergistic effect in the combustion of the mixed bio-coal and anthracite, and the combustion temperature range of bio-coal are lower than that of anthracite. Further mixing of bio-coal was helpful to improve the flame stability and reduce the ignition temperature. Kissen-Akahira-Sunose (KAS), FlynnWallOzawa (FWO) and Starink were used for the kinetic analysis, and the statistical R2 factors of the three methods were greater than 0.973, which reflected the high reliability of the calculation methods, and proved that the kinetics of the process are significantly influenced by the calorific rate. Overall, the high-valued utilization of bio-oil and food waste was realized in this study to produce a sustainable fuel.