(336e) Methanol As a Near-Term Solution for Monetizing Renewable Energy and Green Hydrogen.

A sheer scale of human addiction to fossil fuels makes global decarbonization within two or three decades, which is required to prevent extreme consequences of the climate change, an extremely aggressive target. This does not leave much time for development of new power technologies or building new energy infrastructures to replace the ones built over the last two centuries around the use of fossil coal, oil, and natural gas. Production of net-zero carbon hydrocarbon fuels by combining captured CO₂ with green hydrogen produced by water splitting utilizing renewable carbon-free energy sources provides an alternative “shovel ready” de-fossilization solution where renewable fuels compatible with the established energy infrastructures and existing power applications will directly substitute for and gradually replace fuels currently produced from fossil oil, coal, and natural gas. Ultimately this will create the indefinitely sustainable carbon cycle (figure 1) in which CO2 essentially serves as a backbone to which renewable energy is attached in the form of green hydrogen to be used in all existing power applications. No additional extraction of fossil carbon would be required.

Methanol – the simplest alcohol – is a particularly attractive chemical to be used as a large-scale renewable energy carrier. Methanol is stable liquid under wide range of normal ambient conditions. It is already an important commodity chemical with global annual production of about 100 million tonnes and is used in production of 245 different industrial chemicals. Methanol is produced under mild temperature and pressure conditions (about 200-250oC and 30-50 bar), which do not require exotic and expensive alloys for reactor construction, and over inexpensive CuZn based catalysts. Only minor modifications from the existing commercial methanol synthesis process would be required to produce methanol from captured CO₂ and H₂ produced from electrolysis. Well-developed worldwide storage and distribution network for methanol is already established. Methanol is also used in a growing number of energy applications, such as production of biodiesel, methanol blends with gasoline, direct use as automotive and marine fuel, conversion to synthetic aviation fuel, etc.

In order to be able to rapidly substitute for fossil fuels on a global scale cost of production of renewable alternatives should be competitive with the costs of traditional fuels. Cost analysis of a standalone re-methanol plant, which incorporates a wind farm, water electrolysis units, buffering storage for hydrogen and CO2 and a methanol synthesis unit demonstrates that for the near-term case the renewable energy incentives provided by the Inflation Reduction Act reduce the cost of re-methanol production to as low as $232/MT. Under the future case assumptions, the production cost is estimated at $540/MT without incentives. Both costs are lower than the current market prices for grey methanol and are at the lower range of historical prices for other common fuels when normalized to the fuel heating value.

Cost of CO2 remains a significant uncertainty in the cost of re-methanol production. For the near-term production case $50/t_CO2 was used, assuming CO2 capture from industrial point sources. Direct air capture of CO2 (DAC) at $150/t_CO2 was assumed for the future case. Recent advancements in development of DAC technologies indicate that this cost assumption is very reasonable.