DMTO与SMTO甲醇制烯烃工艺的能耗分析及优化节能

Energy consumption analysis and optimization of energy saving of DMTO and SMTO methanol to olefin process

利用Aspen Plus软件对分别采用DMTO和SMTO工艺的甲醇制烯烃工业装置进行了模拟,运用夹点技术分析了2种工艺的节能潜力,并对2种工艺烯烃分离单元分别进行了[火用]分析及节能优化。结果表明:DMTO工艺的加热和冷却负荷的节能潜力分别为30.03,22.79 MW,低压脱丙烷塔、乙烯精馏塔和脱丁烷塔的[火用]效率较低;SMTO工艺的加热和冷却负荷的节能潜力分别为15.97,18.69 MW,乙烯精馏塔、1^(#)和2^(#)丙烯塔的[火用]效率较低;通过优化回流比、塔压、换热介质等操作条件,可使DMTO装置中低压脱丙烷塔、脱乙烷塔、乙烯精馏塔和脱丁烷塔的[火用]效率分别提高5.68,18.94,6.14,31.53个百分点;SMTO装置中脱丙烷塔、乙烯精馏塔和脱乙烷塔[火用]效率分别提高21.99,8.63,73.40个百分点。

Two methanol to olefins processes(DMTO and SMTO)were simulated by Aspen Plus software,their potentials of energy savings were identified based on pinch technology,exergy analysis and optimization of energy saving were performed for distillation columns and those with large exergy losses were identified as key units for modification.The results showed that in DMTO process,the potential of energy saving was 30.03 MW for hot utility and 22.79 MW for cold utility;low-pressure depropane tower,ethylene distillation tower and debutane tower had low exergy efficiency.In SMTO process,the potential of energy saving was 15.97 MW for hot utility and 18.69 MW for cold utility;ethylene distillation tower and the two propylene towers had low exergy efficiency.By changing the operating conditions such as reflux ratio,pressure and medium of heat exchange,exergy efficiency of depropane tower,deethane tower,ethylene distillation tower and debutane tower in DMTO process could be increased by 5.68,18.94,6.14,31.53 percent points respectively,while exergy efficiency of depropane tower,ethylene distillation tower and deethane tower in SMTO process could be increased by 21.99,8.63,73.40 percent points respectively.