Utilization of CO2 and recycling of methanol Residue from the refining process for production of Bio-Methanol

Abstract

This study explores the synthesis of bio-methanol from biogas, focusing on the optimization of carbon dioxide (CO₂) separation via alternating pressure adsorption and subsequent methanol production using varying methane (CH₄) ratios. Methanol synthesis was conducted under CH₄/CO₂ ratios of 30/70, 50/50, and 70/30, utilizing both pure water and methanol solutions at concentrations of 10 %, 20 %, 30 %, and 40 %. The results demonstrated that increasing the CH₄ ratio led to enhanced CO₂ conversion, with maximum values of 42.59 % and methanol production reaching 3,850 g/day. The study further investigated the refining process of crude methanol, achieving a purity exceeding 99 % through a three-column distillation approach. Notably, the recycling of waste methanol significantly improved both methanol yield and CO₂ consumption, indicating a promising pathway for sustainable bio-methanol production. Overall, this research highlights the potential of integrating biogas utilization with efficient methanol synthesis and refining processes.