Process Design and Techno-Economic Analysis of Small-Scale Ethylene Oxide Production by Hydrogen Peroxide Epoxidation

Abstract

Ethylene oxide (EO) is an essential chemical intermediate, but challenges stem from its transportation and storage, as well as its conventional production involving hazardous EO/O2 mixtures. Alternative EO production routes were assessed, which resulted in a safer, small-scale (15 kta) process based on ethanol dehydration to ethylene followed by hydrogen peroxide epoxidation (HPEO). The process is modeled in Aspen Plus, with a detailed three-phase reactor model for HPEO developed in MATLAB to evaluate the operating conditions (i.e., pressure and methanol concentration) and reactor design. The proposed process achieves an EO purity of 99.9 wt % with a moisture content below 10 ppm. Techno-economic analysis gave a minimum production cost of 2.81 $/kg, higher than conventional EO production. Nevertheless, the results demonstrate that the process is feasible at small scale, more sustainable, and a safer alternative to the conventional route, although further feedstock cost reductions and heat integration are required for economic competitiveness.