Evaluation of n-butene synthesis from dimethyl ether in the production of 1,3-butadiene from lignin: A techno-economic analysis

1,3-BD production process from lignin consisting of four unit operations such as gasification, dimethyl ether (DME) synthesis, n-butene synthesis, and isomerization/dehydrogenation, was simulated. This process could be designed as a renewable energy system that can not only produce 1,3-BD but also self-supply almost all the heat and power for the operation. The balance of payment (BP), which is the income incurred from processing a unit weight of lignin, was employed as the economic efficiency of the process. The effect of the reaction conditions in the DME to n-butene synthesis step (the third step) on the BP was investigated. Since few catalysts have been reported for synthesizing n-butene from DME, realistic reaction conditions and catalytic performance were set. An increase in the DME content of the feed gas and a decrease in the reaction pressure led to an increase in the n-butene yield and a decrease in the power, followed by an increase in the 1,3-BD yield and BP. Considering the expected power selling price after the termination of the Feed-in-Tariff scheme, the 1,3-BD production process could have comparable BPs with gasification power generation as a representative competitive process.