十氢萘和环己烷气相氧化裂解过程的研究

STUDY ON GAS PHASE OXIDATIVE CRACKING OF DECALIN AND CYCLOHEXANE

采用石英管反应器,在常压下研究了十氢萘和环己烷的气相氧化裂解(GOC)过程。结果表明,O2的存在降低了十氢萘GOC反应的活化能,使反应在较低的温度下具有高的转化率;O2同时能起消除积炭的作用,提高体系的抗积炭能力。与环己烷GOC反应不同,双环的十氢萘分子在开环裂解生成低碳烯烃的同时,可获得较高的液体收率。低温下,十氢萘GOC反应所得的液体中富含烷基苯、烷基环己烷和支链烷烃,而高温下GOC反应得到的液体富含苯、甲苯和二甲苯(简称BTX)。在800℃,n(C)/n(O)=2.5时,十氢萘GOC反应可获得低碳烯烃收率38.91%和液体收率47.97%,液体中BTX的质量分数为59.88%。在环烷烃的GOC过程中,低温下O2主要进行氧化脱氢反应,高温下则更多的参与COX的生成;在相同反应条件下,O2的存在使多环烷烃比单环烷烃具有更高的开环裂解活性,更易发生生成CO的部分氧化反应。

The gas phase oxidative cracking （GOC） processes of decalin and cyclohexane were investigated by using the quartz tube reactor at atmospheric pressure. The results showed that the activation energy of decalin for GOC was decreased and the higher conversion was obtained at lower temperature due to the presence of O2, which also played an important role in decoking, enhancing the anticoking ability of the reaction system. It is different from GOC of cyclohexane that GOC of decalin produced not only a large amount of low alkenes, but also much liquid. The liquid was composed of alkylbenzene, alkylcyclohexane and branched alkanes at lower temperatures, while it mainly contained benzene, toluene and xylene （BTX） at higher temperatures. The low alkene yield of 38.91% and liquid yield of 47.97% were obtained in GOC of decalin under the conditions of 800℃ and n（C）/n（O） of 2.5, and the mass fraction of BTX in the liquid was 59. 88%. For GOC of cycloalkanes, O2 participated primarily in the oxydehydrogenation reaction at lower temperature, while at higher temperature in the partial oxidation reaction to produce CO. When compared with GOC of cyclohexane, a higher ring opening activity was obtained in GOC of deealin under the same reaction conditions.