A number of processes exist to convert coal, biomass, and other carbonaceous materials to clean-burning fuels, but they tend to be too expensive to compete on the market with petroleum-based fuels, or they produce volatile fuels, such as methanol and ethanol that have vapor pressure values too high for use in high pollution areas
This new invention provides a method that is less expensive than known processes to convert carbonaceous material to clean-burning fuels. Specfically, carbonaceous material, which can comprise municipal waste, biomass, wood, coal, or a natural or synthetic polymer, is converted to a stream of methane and carbon monoxide rich gas by heating the carbonaceous material in a fluidized bed reactor using steam and/or hydrogen, preferably both, as fluidizing medium at a temperature and pressure sufficient to generate a stream of methane and carbon monoxide rich gas but at a temperature low enough and/or at a pressure high enough to enable the carbonaceous material to be fluidized by the hydrogen or by a mixture of hydrogen and steam. Preferably, the temperature is about 700° C. to about 900° C. at a pressure of about 132 psi to 560 psi, preferably 150-400 psi. Impurities are removed from the stream of methane and carbon monoxide rich gas at substantially the pressure of the fluidized bed reactor at a temperature above the boiling point of water at the process pressure.
|United States Of America||Issued Patent||8,741,000||06/03/2014||2006-578|
|United States Of America||Issued Patent||8,143,319||03/27/2012||2006-578|
|United States Of America||Issued Patent||7,619,012||11/17/2009||2006-578|