Biomethanol Production from Renewable Sources and CO2 Derived from Biogas

Abstract

Methanol is a key chemical and fuel component, with increasing interest in renewable methanol production to reduce reliance on fossil fuels and mitigate carbon emissions. This study presents a sustainable process for methanol production from biogas, integrating biogas upgrading, methane steam reforming and CO₂ hydrogenation. A physical separation process using cold methanol at high pressure is implemented before the reforming and hydrogenation stages to selectively capture and purify CO₂ from biogas. The methane-rich stream undergoes reforming to produce syngas, supplying the hydrogen required for CO₂ hydrogenation and enhancing process efficiency. The overall process is modeled in Aspen Plus V12.1 to analyze system configurations and process parameters. The research framework evaluates the potential of biogas-derived methanol as a scalable and sustainable fuel alternative, supporting the transition to carbon-neutral chemical production. Additionally, a sensitivity analysis was conducted for both methane reforming and catalytic methanol synthesis reactions, aiming to identify optimal parameters for maximizing methanol production. This study investigates the efficiency and environmental impact of a biogas-based methanol production process, emphasizing CO₂ utilization and overall process performance. The CO₂ conversion efficiency reaches 99.22 %, with an overall process CO₂ conversion of 53.29 %. The process achieves net direct CO2 emissions of -260.52 kmol/h, meaning it actively removes CO₂ from the atmosphere, and its carbon intensity is only 255.52 g CO₂ per kilogram of methanol-representing an overall direct emission reduction of up to 85 %.