Study On Low Temperature Co-pyrolysis Of Biomass And Low Rank Coal

China abounds with coal resources, especially for low rank coal reserves which accountedfor about40%of the total reserves. And low rank coal has higher ratio of H/C and volatile.Through the low-temperature pyrolysis can obtain higher value tar. While biomass as a kind ofhydrogen-rich resource, with many advantages, such as large reserves, low-cost, renewable, andcan achieve zero emission of CO₂. but its utilization rate is very low. Based on the above features,biomass can be used as hydrogen donor during the co-pyrolysis process. In addition, theproduction cost can be reduced and the conversion rate of coal can be improved, as well as it canachieve effective utilization of natural resources and upgrading of coal tar.In this experiment, the wild duckweed and long flame coal as raw material, the co-pyrolysisexperiments with different ratio were carried out in a dry distillation equipment, and focusing onthe coal tar with GC-MS in order to investigate the changes in coal tar. Using thermalgravimetric analysis and kinetic model to study the change trend of TG-DTG cures and obtainingpyrolysis parameters from the view of dynamics. Then exploring the co-pyrolysis mechanismwith biomass added. Research shows：（1） The yield of tar and the content of high-value chemicals such as linear paraffins,phenol, naphthalene, benzene, fluorine, indene compounds were increased with the biomasscontent increasing, when the content up to40%, the tar yield increased from8.74%to18.58%, itindicated the coal tar was upgraded.（2） With the increasing of biomass content, the mass loss rate of sample was increasedgradually, TG curve moved to the low temperature region, and the initial pyrolysis temperaturewas advanced. When the biomass content is less than30%, the mass loss rate of sample washigher than calculated. beneficial synergistic effect of co-pyrolysis existed which promoted thepyrolysis reaction. The synergistic effect in high temperature was more obvious. When thebiomass content is higher than30%, the mass loss rate was smaller than calculated. negativesynergistic effect existed and inhibited the pyrolysis reactions.（3） The activation energy and pre-exponential factor of co-pyrolysis was reduced graduallywith the increasing of biomass content. And the thermal decomposition kinetics modelconformed to the first-order kinetic equation.