Life Cycle Assessment of CO2-Based and Conventional Methanol Production Pathways in Thailand

Abstract

Methanol production through carbon capture and utilization technologies offers promising alternatives to traditional natural-gas-based methods, potentially mitigating climate change impacts and improving resource efficiency. This study evaluates four methanol production pathways: CO2 hydrogenation, tri-reforming of methane, electrochemical CO2 reduction, and co-electrolysis of CO2 and water. The analysis covers 19 scenarios, combining three electricity mixes (100% Thai grid mix, 50% Thai grid mix and 50% renewable energy, and 100% renewable energy) with two hydrogen production technologies (alkaline water electrolysis and grey hydrogen). Environmental life cycle assessment results showed that most pathways perform well when using the 100% renewable energy with co-electrolysis (CE-100%) showing the most substantial reductions across all impact categories as compared conventional methanol production. Electrochemical reduction demonstrated the poorest environmental performance for all scenarios. In Thailand, implementing the CE-100% pathway could potentially yield 12.4 million tonnes of methanol annually from the cement industry’s CO2 emissions, with an estimated value of approximately USD 5.4 billion, while reducing emissions from the industrial processes and product use (IPPU) sector by 75%. The findings provide valuable insights for policymakers, industry stakeholders, and researchers, supporting Thailand’s transition towards sustainable methanol production and broader climate goals.