Patent ID: 8690977

Claim:
A method for processing a carbonaceous feedstock, the method comprising the steps of: (a) providing a carbonaceous feedstock; (b) preparing a feedstock slurry from said carbonaceous feedstock, wherein said feedstock slurry comprises between 40% and 80% water; (c) optionally pre-heating said feedstock slurry prior to devolatilizing; (d) devolatilizing said feedstock slurry at a pressure between 300 and 900 psia such that the water in the slurry does not flash to steam while heating at a temperature between 300 and 600 degrees F. for between 5 and 30 minutes, to generate a char slurry comprising char and between 40% and 80% water; (e) introducing a pressure decrease in the flow of said char slurry from the devolatilization step to the gasification step, such that at least a portion of the water flashes to steam to produce a steam char slurry; (f) subjecting said steam char slurry to gasification at a temperature between 1500 and 2000 degrees Fahrenheit, to generate a product gas comprising methane; (g) supplying said product gas to a primary energy generator to generate mechanical or electrical power, wherein a heated fluid, either gas or liquid, is exhausted; and (h) indirectly heating at least one of said feedstock slurry and said char slurry, utilizing said exhausted heated fluid; wherein steps (d), (e) and (f) directly follow one another.