Technoeconomic and Life Cycle Analysis of Synthetic Methanol Production from Hydrogen and Industrial Byproduct CO₂

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.