NOVELTY - Producing methane from a carbonaceous material involves conveying pulverized carbonaceous material entrained in an inert carrier fluid (preferably carbon dioxide) into a reactor; exposing the carbonaceous material in the reactor to a swirling stream of a hydrogen gas to react the carbonaceous material with the hydrogen gas and form an exit gas that includes the methane; and extracting the exit gas from the reactor in response to the exposing operation. The reactor includes a vortex region for receiving hydrogen gas and imparting a swirling motion to the hydrogen gas.    USE - For producing methane from a carbonaceous material, such as coal.    ADVANTAGE - The hydrogasification system reacts carbonaceous material with hydrogen in the absence of liquid water, steam, or oil by utilizing an inert carrier fluid (i.e. carbon dioxide) to convey a particulate form of the carbonaceous material. The hydrogasification technology dictates a partial combustion of raw coal to prevent the coal particles from sticking together. Entrainment in carbon dioxide isolates the particles of pulverized coal from one another to mitigate the caking problem. The utilization of the dry feed system eliminates the need for preparation of a conventional oil and coal slurry. The cost savings is achieved at the fuel feed system since there is no need for a fluid-bed reactor for the partial combustion of the raw coal. There is also no need for a slurry-feed system, a slurry-circulating pump, and specialized materials that are resistant to degradation by the slurry oil. In addition to its ability to mitigate coal caking problems, and to eliminate the need for coal pre-treatment and the preparation of coal slurry, carbon dioxide is also advantageously utilized as an inert carrier fluid for pulverized coal because it is less likely to react, so lower levels of carbon monoxide and non-methane hydrogen compounds will be formed in reactor, thus driving greater methane production. Since the inert carrier fluid remains inert in the reactor, thus achieving a high efficiency of reaction of carbon and hydrogen. The effective delivery of pulverized coal entrained in carbon dioxide and reaction with hydrogen produces exit gas having a very high methane concentration and low carbon monoxide and carbon dioxide concentrations. The majority of carbon dioxide can be vented to a tank so that it can be recompressed and reused in the next cycle, and additional carbon dioxide can be readily injected into the system since it is available as a waste gas from numerous other processes. The utilization of carbon dioxide as an inert carrier fluid, and in the absence of water, simplifies reactor design and cost, as well as reduces water requirements. The reduction in the use of water is advantageous in an arid environment where water is a relatively scarce commodity.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a hydrogasification system for producing methane from a carbonaceous material comprising a pulverizer for forming particulates of the carbonaceous material; and the reactor in communication with the pulverizer, including a fuel feed element; vortex region for receiving hydrogen gas and imparting swirling motion to the hydrogen gas to form a swirling stream of the hydrogen gas; a reaction tube; and a reactor outlet in fluid communication with the reaction tube for extracting the exit gas from the reactor.    DESCRIPTION OF DRAWING(S) - The figure shows a block diagram of a hydrogasification system.