Technoeconomic and Life Cycle Analysis of Synthetic Methanol Production from Hydrogen and Industrial Byproduct CO<sub>2</sub>
Guiyan Zang, Pingping Sun, Amgad Elgowainy, Michael Wang
Abstract
CO2 capture and utilization provides an alternative pathway for low-carbon hydrocarbon production. Given the ample supply of high-purity CO2 emitted from ethanol and ammonia plants, this study conducted technoeconomic analysis and environmental life cycle analysis of several systems: integrated methanol–ethanol coproduction, integrated methanol–ammonia coproduction, and stand-alone methanol production systems, using CO2 feedstock from ethanol plants, ammonia plants, and general market CO2 supply. The cradle-to-grave greenhouse gas emissions of methanol produced from the stand-alone methanol, integrated methanol–ethanol, and integrated methanol–ammonia systems are 13.6, 37.9, and 84.6 g CO2-equiv/MJ, respectively, compared to 91.5 g CO2-equiv/MJ of conventional methanol produced from natural gas. The minimum fuel selling price (MFSP) of methanol ($0.61–0.64/kg) is 61–68% higher than the average market methanol price of $0.38/kg, when using a Department of Energy target renewable hydrogen production price of $2.0/kg. The methanol price increases to $1.24–1.28/kg when the hydrogen price is $5.0/kg. Without CO2 abatement credits, the H2 price needs to be within $0.77–0.95/kg for the MFSP of methanol to equal the average methanol market price. With a CO2 credit of $35/MT according to tax credit per metric ton of CO2 captured and used, the methanol price is reduced to $0.56–0.59/kg.