乙烯在煤焦及石英砂床层上裂解实验研究

以石油炼制过程中产生的炼厂气与煤共转化利用为背景，采用小型石英管固定床反应装置，在850℃～1000℃下，对乙烯在空床、彬县煤焦以及石英砂床层上的裂解反应进行了研究。结果表明，乙烯裂解产物包括氢气、甲烷、乙烷及裂解炭，反应温度越高，裂解越彻底，生成的氢气越多；850℃～950℃时，乙烯在彬县焦上初始转化率最高，随着反应的进行逐渐降低到一个较低的平衡值，并且与在石英砂上裂解结果接近。这说明新鲜彬县煤焦对乙烯裂解呈现良好的催化作用，但随着反应进行其催化活性由于裂解生成的炭沉积在煤焦表面而逐渐丧失。1000℃时乙烯在石英砂上和空床裂解转化率均可达到94％，即在此温度下乙烯无需催化剂通过热作用即可接近完全裂解。

Cracking of ethylene over coal char or quartz

The cracking of ethylene as one of the major components of oil refinery over a bed of Binxian char and quartz, respectively, has been studied in a fixed bed reactor at temperatures between 850℃ and 1000℃ and atmospheric pressure. The results show that the conversions of ethylene increases with increasing temperature. The products of ethylene cracking are H₂, CH₄, C₂H₆ and C. The higher the reaction temperature, the more complete ethylene cracking and the more H₂ produced. The higher initial conversion rate of ethylene cracking at 850℃ to 950℃ is only observed over Binxian char but not on quartz and an empty reactor. This indicates a significant catalytic effect of Binxian char on ethylene cracking. Ethylene conversion decreases with reaction time due to carbon deposition on the char surface. The conversion of ethylene is 94% over quartz and in the empty reactor at 1000℃, suggesting that ethylene can completely decompose through thermal cracking without catalyst.