Green methanol
Feb 24 issue of C&EN has detailed article on methanol as a fuel. Methanol is of interest as a hydrogen equivalent to fuel ocean ships. Compared to ammonia it is less toxic and easier to store but is a red label flammable liquid.
They compare four sources of methanol: natural gas, biomethane as from manure or trash, biomass from gasification of forest residues, and e-methanol from electrolysis green hydrogen with captured carbon dioxide. The heat of combustion of methanol is 62,004 btu/gal compared to 152,000 for diesel fuel indicating 2.45 gal of methanol needed to replace a gallon of diesel fuel.
They provide cost estimates for each process (as shown in the table). From natural gas, the cost of methanol is $1.19/gal, equivalent to $2.91 to replace diesel. Not a bad differential. $3.46 with carbon capture.
Biomass looks most feasible at $2.18/gal or 5.34 equivalent–about double but with CO2 reduction from 107 to 15 g/MJ. Electrolysis processes are very expensive. $3.62 & 8.88equiv to 7.06 & 17.31.
Methanol C&EN Feb 24 2025
From CO2 Emissions cost $/Mton avg $/ton $/gal Fuel equiv
Natural gas 103 to 110 g/MJ 350-450 400 1.19 2.91
w capture 400-550 475 1.41 3.46
Biomethane -103 to -38
Biomass 10 to 20 455-1013 734 2.18 5.34
Electrolysis 4.4 820-1620 1220 3.62 8.88
w capture to 2380 2380 7.06 17.31
density= 0.7866 6.53 lb/gal
% Oxygen 49.93
heat of combustion 9.8 btu/lb 63.982044 btu/gal
22 kJ/g 65414 kj/gal
62003.7914691943 btu/gal
Diesel fuel 152,000 btu/gal
Fuel equiv 2.45 gal MeOH to equal diesel fuel