Bench scale demonstration of the Supermethanol concept: The synthesis of methanol from glycerol derived syngas

An integrated process for the synthesis of methanol from aqueous glycerol involving reforming of the feed to syngas followed by methanol synthesis is successfully demonstrated in a continuous bench scale unit. Glycerol reforming was carried out at pressures of 24–27 MPa and temperatures of 948–998 K with a throughput of approximately 1 kg aqueous feed/h (3–10 wt.% glycerol) leading to high glycerol conversions of (95.0–99.9%) and syngas with a composition range of H2/CO/CO2/CxHy = 44–67/1–21/16–34/2–18 vol.%. The effluent water of the process was recycled at high pressure, reducing the water consumption of the process significantly. Subsequent syngas conversion to methanol was carried out in a packed bed reactor at temperatures between 468 and 518 K and pressures between 24 and 27 MPa using a commercial methanol catalyst (Cu/ZnO/Al2O3). The maximum yield of methanol based on glycerol intake was 0.62 kg methanol/kg glycerol for an experiment with a time on stream of 16 h, which corresponds to a carbon conversion (carbon in methanol over carbon in glycerol) of 60%. This value is close to the maximum theoretical yield of 78% based on stoichiometric considerations.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlight• Glycerol reforming in supercritical water and methanol synthesis were integrated. • The continuous integrated set-up was operated steadily for over 16 h. • The maximum methanol yield was 0.62 kg methanol/kg glycerol. • High pressure recycling of effluent water in the reforming section was demonstrated. • High pressure methanol synthesis from glycerol derived syngas was demonstrated.