Hydromethanation, [hahy-droh- meth-uh-ney-shuhn] is the process by which methane (the main constituent of natural gas) is produced through the combination of steam, carbonaceous solids and a catalyst in a fluidized bed reactor.
The process, developed over the past 60 years by multiple research groups, enables the highly efficient conversion of coal, petroleum coke and biomass (e.g. switchgrass or wood waste) into clean, pipeline quality methane.
The process utilizes a specially designed reactor and depends upon a proprietary metal catalyst to promote chemical conversion at the low temperatures where the water gas shift reaction and methanation take place.
The development of hydromethanation is an example of process intensification, where several operations are combined into a single step to improve overall efficiency, reduce maintenance and equipment requirements, and lower capital costs.
In addition to methane, hydromethanation produces a high-purity stream of carbon dioxide (CO2), an odorless, colorless greenhouse gas.