Maximum Single Train Ethylene Capacity

The technology options available to convert CO₂ into higher value fuels and chemicals are not commercially well established. Developing commercially viable technologies to convert CO₂ into high value products will improve the project economics of renewable and non-renewable carbon-based energy production. Such technologies can potentially create additional revenue streams with significant reduction in the net CO₂ emissions. A well-known pathway for CO₂ utilization is reforming of CH₄ in presence of steam and CO₂ (bi-reforming of CH₄) for syngas (CO+H₂) production. The syngas can then be used as a raw material for synthesis of fuels and chemicals, including methanol. The specific reactant stoichiometric ratio of CH₄/steam/CO₂ of 3/2/1 creates the syngas ratio of 2 which is critical for methanol synthesis. In this context, an Aspen plus process simulation model for bi-reforming reaction system coupled with the methanol synthesis reactor system is developed. The model considers a range of operating conditions and is used to optimize the integrated process. Under optimum operating conditions, the overall process thermal efficiency is 65%. The results from process simulation are used to conduct a Life Cycle Analysis (LCA) of the proposed pathway. Net GHG emissions from conventional steam methane reforming based methanol is about 497 kilograms of CO₂e/tonne of methanol whereas the GHG emissions from the proposed bi-reforming based process is about 203 kilograms of CO₂e/tonne of methanol produced on an LHV basis. The proposed technology can reduce about a million tonnes of CO₂ equivalent GHGs per year in a 10,000 tonne methanol/day plant.