乙烯氧乙酰化固定床反应器的模拟与催化剂分布优化

SIMULATION AND CATALYST DISTRIBUTION OPTIMIZATION IN FIXED-BED REACTOR FOR ACETOXIDATION OF ETHYLENE

采用拟均相一维和二维模型对乙烯氧乙酰化工业固定床反应器进行了数学模拟,结果表明:反应器进口气温即为热点温度,可以进一步提高催化剂活性和生产能力.当催化剂活性达到现活性的3倍时,传统的反应器将出现热失控(飞温).采用分段填装高活性催化剂的优化分布,可以大大降低反应器的热敏感性,提高反应转化率和选择性.例如,用两段填装催化剂平均活性(?)=2的反应器代替一段填装催化剂的反应器时,热点温度降低了13.9℃,乙烯转化率和乙烯转化为醋酸乙烯的选择性分别提高了1.46%和1.41%.

The industrial fixed- bed reactor for acetoxidation of ethylene was math- ematical-ly simulated by pseudo- homogeneous one- dimensional and two- dimensional reactor models. The results showed that the gas temperature at the entrance of the reactor was close to the temperature of hot - spot, and that the activity of catalyst and productivity of reactor could be further increased. But,thermal runaway for a normal reactor may occur when the activity of catalyst was three times that of the present catalyst. The optimal distribution of a high active catalyst multiple- sectionally loaded in the reactor may greatly reduce the sensitivity of heat and may improve the conversion and selectivity of the reaction. For example,if a catalyst with mean activity two times that of the present catalyst was loaded in the reactor in two sections to replace the normal reactor loaded in one-section of catalyst,the temperature of hot-spot may be reduced by 13. 9℃ ,and the conversion of ethylene and the selectivity of vinyl acetate from ethylene may be increased by 1. 46% and by 1. 41% respectively.