丁烷氧化制顺酐固定床反应器人为非定态操作性能的研究

Investigation on Unsteady State Performance of n-Butane Selective Oxidation to Maleic Anhydride in a Fixed-Bed Reactor

丁烷选择氧化制顺酐是迄今唯一已经工业化的低碳烷烃选择氧化反应 .模拟研究和在实验室微型反应器上的研究结果证实 ,在适宜的操作条件下 ,通过固定床反应器人为非定态操作能够改善反应的时均性能、提高顺酐的选择性和收率 .本文在小试规模 (装填 30 g原粒度工业催化剂 )的单管固定床反应器实验装置上 ,开展了丁烷选择氧化反应人为非定态操作性能的研究 .在适宜的操作条件下 ,进料组成周期性变化虽然提高了顺酐的选择性 ,但降低了丁烷的转化率 ;

Currently, the selective oxidation of n butane to maleic anhydride (MA) over vanadium phosphorus oxide (VPO) catalysts is the only industrial process involving the selective oxidation of a light alkane. Unsteady state operation offers a new means of controlling total oxidation by segregating the hydrocarbon feedstock from oxygen. That is, splitting up of the overall reaction in spatial or temporal into two steps,hydrocarbon selective oxidation and reoxidation of the reduced catalyst, and matching each step with suitable reaction condition. In this paper, a single tube wall cooled fixed bed reactor filled with 30 g of cylindrical catalyst was set up, and periodic operation performance was investigated. Feed composition modulation enhanced the selectivity for maleic anhydride but dropped the butane conversion and the maleic anhydride yield. A new modulation scheme of both reaction temperature and feed composition was also examined. With a 0 4 of cycle split and period of 8 min, reoxidation at 530 ℃ and selective oxidation at 405 ℃, the yield of maleic anhydride by both the reaction temperature and feed composition modulation was improved by 11 4% than that operated in steady state at the same time average flow of n butane. It indicated that the higher reoxidation temperature was effective to improve the reaction performance.