Experiment Study On Semicoke Gasification In Fluidized Bed

Lignite has been paid more attention since the decrease of high-quality energyresource. Based on pyrolysis and gasification, lignite could be utilized efficiently. As apart of the project ‘the demonstration project of lignite utilization with capacity of1.2million tons/a’, semicoke, the solid product of lignite pyrolysis for gasification isinvestigated in this paper.The experiment system, whose reaction zone is1086mm with600mm high,was debugged firstly. The semicoke gasification with steam and air asgasification agent was conducted to testify the repeatability and reliability of thesystem.The result of semicoke produced by Shuicheng lignite pyrolysis shows thatthe yield of semicoke is61.4%in which the volatiles is19.99%as the dry baseat800, which is much lower than that of initial lignite of47.85%.The semicoke produced from Shuicheng lignite is gasified in steam and airin order to study the influence of steam/semicoke ratio, air/semicoke ratio, andthe experiment temperature on gas composition, gas production rate andcalorific value. The results show that steam/semicoke ratio and the experimenttemperature are two important influence factors, with the highest calorific valueof4.45MJ/Nm3.Furthermore, the experiments are conducted with steam, air and oxygenand the results indicate that the increase of oxygen can significantly improve thequality of the gas, with the highest calorific value of5.80MJ/Nm3. At highoxygen percentage, the H2/CO ratio can be adjusted largely by the amount ofsteam, while slightly changed by the experiment temperature.