甲醇製烯烴製程之設計暨經濟與減碳效益分析

The design, economic and carbon reduction analysis of a methanol-to-olefins process

謝汶(Wen Hsieh)

指導教授 ： 張煖

淡江大學/工學院/化學工程與材料工程學系碩士班/碩士(2021年)

https://doi.org/10.6846/TKU.2021.00396

摘要

碳排放之管制將有大量來自電廠與製程之二氧化碳捕獲，利用二氧化碳生產的甲醇可以做為燃料或化學品，是最可行的二氧化碳再利用方式之一。乙烯/丙烯是石化工業上游大宗原料，可以透過甲醇製造烯烴(MTO, Methanol to Olefins)技術生產。本論文針對工業級甲醇轉烯烴製程進行完整流程設計，包括反應段、分離段與冷凍循環，並針對最耗能的產物分離與回收段程序進行優化設計，採用蒸餾塔能耗目標分析改善蒸餾序列各蒸餾塔之設計，並納入冷箱以改善最低溫段的分離性能與能效。
甲醇製烯烴製程採用UOP/Hydro反應器性能，同時生產36萬噸/年乙烯與36萬噸/年丙烯。相較於基本個案設計，優化設計之可用能損失降低了40%，乙烯損失率降低了36%。優化設計之IRR為30.2%且甲醇價格對經濟效益影響重大。甲醇轉烯烴程序之單位產品能耗與二氧化碳排放分別為1.9 GJ/MT乙烯與0.3 MT CO2/MT olefins，均低於傳統蒸氣裂解製程，若涵蓋前端利用二氧化碳之甲烷產甲醇製程，則可獲得淨減碳的效益，達-0.4 MT CO2/MT olefins。

關鍵字

甲醇 ； 烯烴 ； 蒸餾 ； 冷凍系統 ； 冷箱

並列摘要

Carbon emission control will generate significant amount of carbon dioxide from the carbon capture facilities of power plants and various industries. Generation of methanol as fuel or chemical is one of the most feasible way of carbon dioxide utilization. Furthermore, ethylene and propylene, which are the most important commodity raw materials of petrochemical industry, can be produced from methanol via the methanol-to-olefins (MTO) technology. This thesis presents the overall process design, including reaction and separation sections as well as refrigeration cycles, of an industrial-scale MTO process. Optimal design focuses on the product separation and recovery section, which is the most energy consuming part of the process. Column targeting analysis is employed to improve distillation column design and a cold-box is added to improve the separation performance and energy utilization of the lowest-temperature part of the process.
The MTO process is based on the reactor performance of UOP/Hydro technology and produces polymer-grade ethylene and propylene with a capacity of 360 kt/y each. Compared to the base design, the optimal design reduces the exergy loss by 40%, the ethylene loss rate is reduced by 36%. The IRR of the optimal design is 30.2% and is highly dependent on the methanol price. The optimal MTO process is superior to the conventional ethane and naphtha steam cracking in energy consumption and carbon dioxide emission and the results are 1.9 GJ/MT ethylene and 0.3 MT CO2/MT olefins, respectively. The combination of the MTO process and its feedstock production process, i.e. the methanol process from methane reforming with utilization of carbon dioxide, generates a carbon reduction effect of 0.4 MT CO2/MT olefins.

並列關鍵字

methanol ； olefins ； distillation ； refrigeration ； cold-box

參考文獻

參考文獻

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