Catalytic gasification of Fujian anthracite in CO2 with black liquor by thermogravimetry

The CO2 gasification of Fuijian anthracite using black liquor (BL) as a catalyst was performed in a thermogravimetry analyzer (TGA) under temperatures ranging from 750 °C to 950 °C at ambient pressure to evaluate the catalytic effect of 3%, 5%, 8%, 10% Na-BL-Loading on carbon conversion. Better catalytic activity was found with 8% Na-BL-Loading than those of other concentrations. Under the reaction control conditions, the relationships of coal conversion vs reaction time of three kinds of Fuijian high-metamorphous anthracites were measured within temperature range from 750 °C to 950 °C. Both homogeneous model (HM) and shrinking-core model (SCM) were applied to correlate the relations between conversion and time and to determine the reaction rate constants (k) under different temperatures, then the reaction activation energy (Ea) and the pre-exponential factor (A) of the three anthracites were predicted by using Arrhenius equation k = A·exp(Ea/RT). The Ea ranged from 76.18 kJ/mol to 104.22 kJ/mol at 8% Na-BL-Loading condition was detected, which is less than that from 150.93 kJ/mol to 185.44 kJ/mol at non-catalyst case, clearly demonstrating that the BL could be the source of inexpensive and effective catalyst for coal gasification.