Comparative life cycle environmental, exergteic, and economic assessment of three hydrocarbon-based ethylene production routes

Abstract

Currently and in the foreseeable future, steam cracking with sequential cryogenic separation, steam cracking with de-ethanization cryogenic separation (SC-DES), and steam cracking with de-propanization cryogenic separation are the primary ethylene production routes in China. In the era of carbon peaking and carbon neutrality, academia and industry focus on the high-quality development of manufacturing. In this study, a general framework integrating life cycle assessment (LCA), exergetic life cycle assessment (ELCA), and life cycle costing (LCC) was constructed to compare the comprehensive performance of three routes systematically. Furthermore, the model of the foreground process was developed by COILSIMID and Aspen Plus with two typical cracking feedstocks, naphtha and LPG. Based on these, eleven significant indicators from the LCA, ELCA, and LCC integrating framework were calculated to reflect the production performance from environmental, exergetic, and economic perspectives in three ethylene production routes. The results indicated that the overall categories of the SC-DES route are better than the other two routes, but a few indicators lack competitiveness. Since no route showed excellent performance in all indicators, it was not easy to declare that a certain path has the best sustainable performance. However, decision-makers can utilize the obtained results to make optimal decisions beneficial to industrial ethylene production.