气流量和煤样粒度对煤焦-CO_2气化反应的影响

EFFECT OF COAL CHAR SIZE AND REACTION GAS FLOW SPEED ON THE COAL CHAR-CARBON DIOXIDE REACTION

研究了反应气流量和煤样粒度如何影响热天平杯状坩埚内进行的煤焦 - CO2 气化反应 .实验结果表明 :反应气流量和煤样粒度对于煤焦 - CO2 气固相反应有影响 ;随反应气流量增加 ,煤焦反应速率增大 ;恒温和恒升温速率条件下 ,煤样粒度对气化反应影响不同 ,原因是恒升温速率下煤焦气化反应还受到气化温度的影响 .热天平反应单元进口气体由氮气切换为 CO2 后 ,其反应炉内 CO2 浓度变化是一个逐渐增加的过程 ,进口气流量越大 ,反应炉内 CO2

Both the isothermal gravimetric technique and temperature-programmed themogravimetry were applied to the char-carbon dioxide reaction study.A description of the reaction gas flow and the sample size how to affect char gasificaton was presented.Shenfu coal char was prepared by carbonization of Shenfu bituminous in N 2 to 930 ℃,at 20 ℃/min with half an hour soaking time.The result showed that the carbon conversion fraction and reaction rate were higher when higher carbon dioxide flow speed was employed at either isothermal or non-isothermal condition.The smaller coal char particle size was employed in reactions,the higher reaction rate was got at isothermal condition.However,the bigger particle had the higher reaction rate at the end of temperature-programmed thermogravimetry experiment.The influence of mass transport processes to and inside a coal char particle on reactions was obvious.The carbon dioxide concentration was increasing slowly in thermogravimetric apparatus when Nitrogen was shut down and substituted by carbon dioxide.