Today most
methanol is produced from
methane through
syngas.
Trinidad and Tobago is the world's largest methanol producer, with exports mainly to the
United States. The feedstock for the production of methanol comes from natural gas. The conventional route to methanol from
methane passes through syngas generation by
steam reforming combined (or not) with partial oxidation. Alternative ways to convert methane into methanol have also been investigated. These include: • Methane oxidation with homogeneous catalysts in
sulfuric acid media • Methane bromination followed by hydrolysis of the obtained
bromomethane • Direct partial oxidation of methane with oxygen, including trapping of the partially oxidized product and subsequent extraction on copper and iron exchanged
Zeolite (e.g.
Alpha-Oxygen) • Microbial conversion of methane • Photochemical conversion of methane All these synthetic routes emit the
greenhouse gas carbon dioxide CO2. To mitigate this, methanol can be made through ways minimizing the emission of CO2. One solution is to produce it from syngas obtained by biomass gasification. For this purpose any biomass can be used including
wood, wood wastes, grass, agricultural crops and their by-products, animal waste, aquatic plants and municipal waste. There is no need to use food crops as in the case of ethanol from corn, sugar cane and wheat. :Biomass → Syngas (CO, CO2, H2) → CH3OH Methanol can be synthesized from carbon and hydrogen from any source, including
fossil fuels and
biomass. CO2 emitted from fossil fuel burning power plants and other industries and eventually even the CO2 contained in the air, can be a source of carbon. It can also be made from chemical recycling of carbon dioxide, which
Carbon Recycling International has demonstrated with its first commercial scale plant. Initially the major source will be the CO2 rich flue gases of fossil-fuel-burning power plants or exhaust from cement and other factories. In the longer range however, considering diminishing fossil fuel resources and the effect of their utilization on
Earth's atmosphere, even the low concentration of atmospheric CO2 itself could be captured and recycled via methanol, thus supplementing nature's own photosynthetic cycle. Efficient new absorbents to capture atmospheric CO2 are being developed, mimicking plants' ability. Chemical recycling of CO2 to new fuels and materials could thus become feasible, making them renewable on the human timescale. Methanol can also be produced at atmospheric pressure from CO2 by
catalytic hydrogenation of CO2 with H2 where the hydrogen has been obtained from
water electrolysis. This is the process used by
Carbon Recycling International of
Iceland. Methanol may also be produced through CO2
electrochemical reduction, if electrical power is available. The energy needed for these reactions in order to be carbon neutral would come from renewable energy sources such as wind, hydroelectricity and solar as well as nuclear power. In effect, all of them allow free energy to be stored in easily transportable methanol, which is made immediately from hydrogen and carbon dioxide, rather than attempting to store energy in free hydrogen. : Or with electric energy: : : Total: : The necessary CO2 would be captured from fossil fuel burning power plants and other industrial
flue gases including cement factories. With diminishing fossil fuel resources and therefore CO2 emissions, the CO2 content in the air could also be used. Considering the low concentration of CO2 in air (0.04%) improved and economically viable technologies to absorb CO2 will have to be developed. For this reason, extraction of CO2 from water could be more feasible due to its higher concentrations in dissolved form. This would allow the chemical recycling of CO2, thus mimicking nature's photosynthesis. In large-scale renewable methanol is mainly produced of fermented biomass as well as
municipal solid waste (bio-methanol) and of renewable electricity (e-methanol). Production costs for renewable methanol currently are about 300 to US$1000/t for bio-methanol, about 800 to US$1600/t for e-methanol of carbon dioxide of renewable sources and about 1100 to US$2400/t for e-methanol of carbon dioxide of
direct air capture. == Efficiency for production and use of e-methanol ==