# Liquid‐Phase Syngas‐To‐Methanol at Low Temperature: Mixed Alcohol Solvent‐Controlled Pathways for Circular Carbon Manufacturing

## TL;DR

This study shows how using mixed alcohol solvents in low-temperature methanol production can improve efficiency and support circular manufacturing.

## Contribution

The study reveals how solvent composition affects methanol yield and intermediate stability in low-temperature syngas-to-methanol synthesis.

## Key findings

- 2-butanol and isopropanol solvents linearly influence methanol yield based on their composition.
- Isopropyl formate is the only detectable ester intermediate when isopropanol is used.
- The method integrates with waste-to-syngas processes to support circular carbon manufacturing.

## Abstract

Methanol is a primary platform chemical for circular manufacturing. Low‐temperature liquid‐phase methanol synthesis provides an energy‐efficient route for valorizing syngas under mild conditions. In this study, we explore the effect of mixed alcohol solvents—specifically 2‐butanol and isopropanol—on methanol production over a commercial CuO/ZnO/Al2O3 catalyst at 170°C and 5 MPa. These two alcohols were selected based on prior reports of high reactivity, with 2‐butanol showing superior performance but at a higher cost. A series of reactions with varying 2‐butanol content (0%–100%) revealed a nearly linear relationship between solvent composition and methanol yield, suggesting minimal interaction between the two alcohols. Product analysis identified isopropyl formate as the only observable ester intermediate when isopropanol was present, while no 2‐butyl formate was detected. These findings clarify how solvent choice influences intermediate stability and methanol productivity, providing guidance for process optimization. Beyond reaction chemistry, this approach integrates with Regenerative Robust Gasification (RRG), which converts heterogeneous organic waste streams into syngas upstream and channels methanol downstream into products, polymers, packaging, and other circular products, advancing circular economy strategies under industrially relevant conditions.

Low‐temperature liquid‐phase methanol synthesis from syngas was demonstrated over CuO/ZnO/Al2O3 catalysts using mixed alcohol solvents. Solvent composition controls ester intermediate and methanol productivity.© 2026 WILEY‐VCH GmbH