http://www.mit.edu/people/leichen/Thermodynamic_Analysis_of_the_coal_to_SNG_process.pdf From end-to-end in hydromethanation, coal is pulverized and mixed with the selected catalyst. Before feeding the impregnated catalyst-coal into the gasifier, it is dried to remove as much moisture from the fuel as possible. Gasifiers are then fed with the feedstock and begin introducing steam into the environment to perform the gasification. Post the hydromethanation process, carbon monoxide and hydrogen must be separated from the methane product. The cryogenic distillation process effectively separates methane from the synthesis gas (a process with an energy penalty lower than the oxygen separation from air in an ASU).