粗焦炉煤气协同二氧化碳热转化的动力学分析

Kinetic analysis on thermal conversion made by carbon dioxide and crude coke oven gas

通过焦炉煤气干重整回收热态钢渣热量,可同时资源化利用焦炉煤气(COG)与焦炉、钢厂的二氧化碳。重点围绕二氧化碳-粗焦炉煤气热转化过程开展了动力学分析和机理研究,定量考察了温度、CO2与COG入口体积流量比ψ、COG入口体积流量qVCOG(in)、压力p和反应气氛等因素对重整过程的影响,并对反应过程中的原料转化与产物生成规律进行了分析。计算表明:在p=0.1 MPa,qVCOG(in)=1 cm3/s的工况下,为得到产物气氢碳比为2的产物气,粗焦炉煤气直接干重整的合适温度为1600∼2100 K,ψ为0.16∼0.21,对应的产物气中合成气产率γsyn为0.76∼0.92;焦油和CO2转化率分别达到90%和80%以上。在重整介质中添加H2O使得焦油转化率略有提高,CH4转化率、CO2转化率和合成气产率略有降低;添加O2则会提高反应过程温度,明显提高CH4转化率,从而提高产物气产率。

The heat in hot steel slag could be recycled through dry reforming of coke oven gas,and coke oven gas(COG)and carbon dioxide from coke ovens and steel plants could be utilized simultaneously.Kinetic analysis and mechanism study on thermal conversion process of carbon dioxide and COG were made.Effects of temperature,volume flow ratio of CO2 to COG at inlets(ψ),volume flow of COG at inlets(qVCOG(in)),pressure(p)and reaction atmosphere on dry reforming process were investigated quantitatively,and reactants conversion and products formation mechanism in the process were analyzed.The calculation results demonstrate that,in order to obtain the product gas with a hydrogen-carbon ratio of 2,1600—2100 K is the suitable range for reaction temperature and 0.16—0.21 is the suitable range forψfor direct dry reforming process of crude COG when p is 0.1 MPa and qVCOG(in)is 1 cm3/s.At this time,the yield of syngas(γsyn)is 0.76—0.92,and conversion rates of tar and CO2 are 90%and 80%,respectively.Adding H2O into the reforming medium can facilitate tar conversion slightly,but decrease the conversion rate of CH4 and CO2,as well as syngas yield.Addition of O2 would increase the reaction temperature,CH4 conversion rate and syngas yield.