CO2 Self-Sufficiency in Renewable Methanol Production from Biomethane and Biohydrogen: Techno-Economic Assessment for Spain

A. Rascón, J.I. Linares, A. Santos-Montes, E.M. Arenas

Bioengineering Vol. 13, nº. 10, pp. 1183

Summary:

Renewable methanol is commonly proposed either as biomethanol from biomass or biomethane reforming, or as e-methanol from CO₂ hydrogenation using electrolytic hydrogen. This work proposes a third concept: CO₂-self-sufficient biomethanol from biomethane, where biohydrogen and biogenic CO₂ are internally produced through biomethane reforming with carbon capture and utilisation. Four process routes are assessed for Spain, combining conventional CO/H₂ methanol synthesis and CO₂/H₂ hydrogenation. The proposed routes use biohydrogen rather than electrolytic hydrogen. In route 1 (baseline case), fossil methane and CO₂ in conventional methanol production are replaced by renewable alternatives. Route 2 produces hydrogen and CO₂ through steam biomethane reforming with carbon capture and utilisation, generating a CO₂ surplus. Route 3 uses a fraction of biomethane to produce CO₂ and biohydrogen, supplying the CO₂ required by route 1 and yielding excess hydrogen. Finally, route 4 integrates routes 1 and 2, using the CO₂ surplus from route 2 as feedstock for route 1. Routes 1 and 4 produce exclusively methanol and achieve the highest yields (108.6 t and 102.7 t per GWh-HHV of biomethane, respectively). All routes except route 1 are CO₂ self-sufficient. A detailed techno-economic assessment of routes 1 and 4 gives methanol costs of 403–817 €/t and 496–933 €/t, respectively.

Spanish layman's summary:

El estudio compara 4 rutas para producir biometanol a partir de biometano, obteniendo biohidrógeno y sintetizando metanol mediante la hidrogenación de CO y CO₂. La ruta 4, la más favorable, integra las rutas 1 y 2, es autosuficiente en CO₂ y no genera subproductos: produce 102,7 t MeOH/GWh-PCS, con costes de 496–933 €/t según el sustrato.

English layman's summary:

The study compares 4 pathways for producing biomethanol from biomethane, generating biohydrogen and synthesising methanol via CO and CO₂ hydrogenation. Route 4, the most favourable, combines Routes 1 and 2, is CO₂ self-sufficient and generates no by-products: it yields 102.7 t MeOH/GWh-HHV, with costs of €496–933/t depending on the feedstock

Keywords: biomethanol; biomethane; biohydrogen; biogenic CO2

JCR-JIF Impact Factor and WoS quartile: 4,400 - Q2 (2025)

DOI reference: https://doi.org/10.3390/bioengineering13101183

Published on paper: October 2026.

Published on-line: October 2026.

Citation:
A. Rascón, J.I. Linares, A. Santos-Montes, E.M. Arenas, "CO2 Self-Sufficiency in Renewable Methanol Production from Biomethane and Biohydrogen: Techno-Economic Assessment for Spain", Bioengineering, Vol. 13, nº. 10, pp. 1183, October 2026. [Online: October 2026] doi: 10.3390/bioengineering13101183