MTG生产过程模拟及能耗分析

使用Aspen Plus流程模拟软件，采用RKS-BM和NRTL相结合的物性方法，对200 kt/a甲醇制汽油过程进行全流程模拟。模型计算中C6+馏分采用68～201℃虚拟组分表示，考察了将甲醇转化为汽油（MTG）过程的最终产物分布、汽油收率、汽油性质以及装置能耗。计算结果表明，MTG最终的汽油收率不仅与反应器出口C5～C10组分的收率有关，也和汽油的雷氏蒸气压（RVP）密切相关，与汽油馏分中C4组分含量成正比。MTG过程的能耗主要是蒸汽和电的消耗，其中循环气压缩机的电耗占全装置能耗的40.2％。MTG工艺过程中可利用反应热产生中压蒸汽，不仅可回收MTG装置多余的热量，而且使整个装置的能耗大大降低。

SIMULATION AND ANALYSIS OF ENERGY CONSUMPTION FOR MTG PROCESS

A model for simulation of 200kt/a MTG plant was developed using the ASPEN PLUS software. In this model, C6+ mixture in hydrocarbon feed was represented as a pseudo component with distillation range from 68℃ to 201℃. The product distribution, gasoline yield and properties and the utility consumption of unit were investigated. Results show that RVP and the yield of C5-C10 are the most important factors which affect the yield of MTG gasoline, and the yield of MTG gasoline produced from various feedstocks is also proportional to the content of C4 fraction in the gasoline. It is showed from the analysis of energy consumption that a large proportion in the overall utility consumption is occupied by the electricity and steam, in which the consumption of electricity of gas-recycle compressor accounts for 40.2%. Reaction heat in MTG reactors could be used to generate medium pressure steam, by which the energy consumption of the plant can be reduced greatly.