its own set of advantages and limitations. One common feedstock is biomass (biomethanol), which offers the advantage of being renewable and widely available. However, if not managed properly, the use of biomass can raise concerns about land use competition, food security, water use, and biodiversity loss. The use of municipal solid waste (MSW) or waste biomass feedstocks, such as agricultural waste, mitigates the above concerns. Using waste biomass feedstocks requires biochemical or thermochemical conversion processes. Biochemical pathways involve microorganisms fermenting organic materials, such as agricultural residues or forestry waste to produce biogas. This biogas, typically a mixture of methane and CO₂, can be reformed to produce syngas that is then converted to methanol. Thermochemical processes, such as gasification, convert biomass into syngas, which is then catalytically converted into methanol. Johnson Matthey (JM), in partnership with MyRechemical, licences a high feedstock efficiency waste-to-methanol solution (Circular Methanol technology) that integrates waste- to-chemical technology with well-proven methanol synthesis technology and high- performance catalysts. The process uses municipal and industrial waste that cannot be mechanically recycled and chemically recycles it into synthesis gas via a partial oxidation process. The synthesis gas is then purified and conditioned, transformed into methanol, and distilled to the required purity level. Methanol can subsequently be used as a marine fuel or, further, can be converted into other sustainable fuels and chemicals. JM uses its own highly robust methanol synthesis catalyst, offering high stability and methanol productivity. The Circular waste-to-methanol process has also been designed to incorporate green hydrogen, which approximately doubles the amount of methanol that can be produced with the same quantity of waste. The addition of hydrogen may eliminate the requirement for syngas conditioning step(s) and may reduce the carbon intensity of the process even further. The methanol synthesis loop is also able to receive renewable syngas obtained from the gasification of biomass or organic waste to produce biomethanol.
Step 3 Methanol synthesis
Step 2 Gasi cation
Step 1 Feedstock
Municipal solid waste / biomass
Syngas
Methanol
Step 4 Outputs 1
Fuels
Chemicals
Plastics
Step 5 Outputs 2
Oil / gas / petroleum Shipping
Aviation
Stages to sustainable methanol
Another feedstock option for the production of renewable methanol is CO₂, captured from industrial processes or the atmosphere. This CO₂ is then combined with H₂ produced by electrolysis in a catalytic process to produce e-methanol. Waste CO₂-based methanol production offers the potential to recycle carbon emissions as an alternative to extracting fossil fuels. However, the availability and concentration of CO₂ sources can vary, and capturing and processing CO₂ can be energy- intensive and costly. Moreover, electrolytic hydrogen production is the highest contributor to e-methanol production costs, with green H₂ prices ranging from $6/kg (Spain) to $8/kg (US) today. The cost of electrolytic hydrogen is expected to decrease with advances in electrolyser technology and renewable electricity prices. It is expected to drop to $2-3/kg in 2030 in these markets; nevertheless, its current cost poses challenges for the production of e-methanol. Higher feedstock costs and further technical factors mean that the optimisation focus for the design of e-methanol plants shifts to maximising hydrogen and CO₂ conversion into methanol. Methanol synthesis from carbon oxides (COx) and hydrogen is an equilibrium reaction favoured by low temperatures and high pressures. A typical methanol process is operated at 80 bara pressure with peak reaction temperatures of 280°C. At these conditions, the
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