Methanol is a versatile chemical that can be used as a fuel, a solvent, a feedstock for other chemicals, and more. However, most of the methanol produced today comes from fossil fuels, such as natural gas, coal, or oil, which emit large amounts of carbon dioxide (CO2) and contribute to global warming. According to the International Energy Agency (IEA), the global methanol demand was about 100 million metric tons in 2020, and is expected to grow by 3% annually until 2030. This means that more sustainable and low-carbon ways of producing methanol are needed to meet the increasing demand and reduce the environmental impact.
One promising solution is to use renewable energy sources, such as wind, solar, or hydro, to produce hydrogen (H2) and capture CO2 from industrial processes or the atmosphere, and then combine them to make methanol. This process is known as power-to-methanol (PtM), and it can produce methanol with a net-zero or even negative carbon footprint, depending on the source and purity of the CO2. PtM can also help balance the intermittent and variable nature of renewable energy, by storing the excess electricity as methanol, which can be easily transported and used when needed.
However, conventional methanol plants are large-scale, centralized, and capital-intensive facilities, which are not suitable for PtM applications. Therefore, a new approach is needed to enable the distributed and modular production of low-carbon methanol, using small-scale and transportable units that can be located near the sources of CO2 and H2, and the points of use of methanol.
One such approach is being developed by M2X Energy, a company based in Florida, USA, that has created a transportable production unit that converts stranded methane-rich gases into low-carbon methanol. The unit is designed to target the waste streams and flare gases from various industries, such as oil and gas, landfills, wastewater treatment, and agriculture, which contain methane (CH4) and other hydrocarbons that are otherwise vented or burned, releasing greenhouse gases and wasting valuable resources. By converting these gases into methanol, M2X Energy’s system can provide a profitable and environmentally friendly outlet for these waste streams, while also reducing the methane emissions that are 28 times more potent than CO2 as a greenhouse gas.
The core technology of M2X Energy’s system is a patented engine-reformer, which is a modified internal combustion engine that transforms the feed gas into synthesis gas (syngas), a mixture of H2 and CO2, via non-catalytic partial oxidation. The engine-reformer can handle a wide range of feed gas compositions and flow rates, and can also generate heat and power for the rest of the process. The syngas is then compressed and fed into a boiling-water reactor, where a fixed-bed catalyst converts it into crude methanol via CO and CO2 hydrogenation reactions. The methanol is then separated and purified, and the unreacted syngas is recycled back to the reactor. The unit can produce methanol with over 95% purity, and has a capacity of about 300 metric tons per year.
M2X Energy has successfully tested its system at various sites in the US, using different types of feed gases, such as biogas, landfill gas, and associated gas. The company is also collaborating with SCG Chemicals, a global manufacturer based in Thailand, to further optimize the catalytic methanol synthesis steps of the process. M2X Energy’s system is a ‘chemical plant on wheels’ that can be easily deployed and operated at remote locations, and can produce low-carbon methanol at a competitive cost.
Another approach is being pursued by Carbon Recycling International (CRI), a company based in Iceland, that has pioneered the PtM production using renewable electricity and CO2 from geothermal power plants. CRI has built and operated the world’s first commercial-scale PtM plant, called George Olah Renewable Methanol Plant, since 2012, and has produced over 10,000 metric tons of renewable methanol per year, which is sold under the trademark Vulcanol. CRI’s process uses electrolysis to produce H2 from water, and captures CO2 from the flue gas of the geothermal power plant. The H2 and CO2 are then mixed and reacted in a tubular reactor, where a copper-based catalyst converts them into methanol and water. The methanol is then distilled and purified, and the water is recycled back to the electrolyzer. The plant can produce methanol with 99.9% purity, and has a capacity of about 4,000 metric tons per year.
CRI has also developed a modular and scalable PtM technology, called Emissions-to-Liquids (ETL), which can be integrated with various sources of CO2 and H2, such as industrial plants, biogas plants, or hydrogen refueling stations. The ETL technology consists of standardized and containerized modules, which can be easily transported and installed at the desired location. The modules include a CO2 capture unit, a H2 production unit, a methanol synthesis unit, and a methanol purification unit. The ETL technology can produce methanol with 99.5% purity, and has a capacity range of 50 to 500 metric tons per year.
CRI has demonstrated its ETL technology at several sites in Europe and Asia, using different types of CO2 and H2 sources, such as cement plants, steel plants, and biogas plants. The company is also collaborating with Mitsubishi Hitachi Power Systems Europe, a leading engineering company based in Germany, to further commercialize and deploy the ETL technology in various markets and applications. CRI’s technology is a flexible and efficient solution that can produce renewable methanol from various sources of CO2 and H2, and can help decarbonize the transport and chemical sectors.
The following table summarizes some of the key features and differences between the two approaches:
| Feature | M2X Energy | CRI |
|---|---|---|
| Feed gas | Methane-rich waste streams and flare gases | CO2 from industrial processes or the atmosphere and H2 from renewable electricity or excess hydrogen |
| Technology | Engine-reformer and boiling-water reactor | Electrolysis and tubular reactor |
| Methanol purity | Over 95% | 99.5% to 99.9% |
| Capacity | About 300 metric tons per year | 50 to 500 metric tons per year for ETL; 4,000 metric tons per year for George Olah plant |
| Modularity | Transportable production unit | Containerized modules |
| Advantages | Profitable and environmentally friendly outlet for waste gases; reduction of methane emissions; low operating expenses; wide range of feed gas compositions and flow rates; heat and power generation | Net-zero or negative carbon footprint; storage of excess renewable electricity; flexible and efficient integration with various sources of CO2 and H2; standardized and scalable design; high methanol purity |
Both approaches are examples of how the modularized method to make low-carbon methanol can offer multiple benefits for the environment, the economy, and the society, by utilizing renewable or waste resources, reducing greenhouse gas emissions, and providing a clean and versatile fuel and chemical. The modularized method to make low-carbon methanol is a promising and innovative solution that can help meet the growing demand for methanol and support the transition to a low-carbon future.
