Process for the combined coking and gasification of coal
AssigneeMobil Oil Corporation
InventorAnil B. Ketkar
Life of this patent
Estimating the term…
Abstract
A combined gasification/devolatilization process for coal in coal residues is disclosed wherein hydrogen rich volatiles are recovered prior to gasification of the coal. The recovery of hydrogen volatiles is dependent upon the rapid heating of coal obtained by admixture with hot char previously gasified in a riser with steam and a catalyst if necessary. The hot char is provided by combustion of devolatilized coal in a fluid bed regenerator. Alternative systems are provided for purifying the devolatilized coal prior to its charring.
Claims8
A continuous process for the combined devolatilization and gasification of coal comprising the steps of (a) heating devolatilized coal by partial combustion with air in a fluid bed to produce carbon-containing hot char, (b) circulating said hot char to a carbon in said hot char with steam to produce synthesis gas and thereafter separating said synthesis gas and said hot char, (d) rapidly mixing said separated hot char with fresh coal in a ratio of 1:1 or greater in a devolatilization fluid bed reactor to recover devolatilized coal, gas and volatiles, (e) separating ash and impurities from said recovered devolatilized coal by burning, and (f) recycling said purified devolatilized coal for heating to produce hot char.
A continuous process for the combined devolatilization and gasification of coal comprising the steps of (a) heating devolatilized coal by partial combustion air in a fluid bed to produce carbon-containing hot char, (b) circulating said hot char to a gasification riser, (c) in said riser, gasifying the carbon in said hot char with steam to produce synthesis gas and thereafter separating said synthesis gas and said hot char, (d) rapidly mixing said separated hot char with fresh coal in a ratio of about 5:1 to about 20:1 in a devolatilization fluid bed reactor to recover devolatilized coal, gas and volatiles, (e) separating ash and impurities from said recovered devolatilized coal by burning, and (f) recycling said purified devolatilized coal for heating to produce hot char.
A continuous process for the combined devolatilization and gasification of coal comprising the steps of (a) heating devolatilized coal by partial combustion with air in a fluid bed to produce carbon-containing but char, (b) circulating said hot char to a gasification riser, (c) in said riser, gasifying siad hot char with steam and a catalyst selected from the group consisting of gaseous SO.sub.2, an SO.sub.2 generating compound, waste CaSO.sub.3 sludge, lime, limestone and dolomite to produce synthesis gas, and thereafter separating said synthesis gas and said hot char, (d) rapidly mixing said separated hot char with fresh coal in a ratio of 1:1 or greater in a devolatilization fluid bed reactor to recover devolatilized coal, gas and volatiles, (e) separating ash and impurities from said recovered devolatilized coal by burning, and (f) recycling said purified devolatilized coal for heating to produce hot char.
A continuous process for the combined devolatilization and gasification of coal comprising the steps of (a) heating devolatilized coal by partial combustion with air in a fluid bed to produce carbon-containing hot char, (b) circulating said hot char to a gasification riser, (c) in said riser, gasifying said hot char with steam and a catalyst selected from the group consisting of gaseous SO.sub.2, an SO.sub.2 generating compound, waste CaSO.sub.3 sludge, lime, limestone and dolomite to produce synthesis gas, and thereafter separating said synthesis gas and said hot char, (d) rapidly mixing said separated hot char with fresh coal in a ratio of 5:1 to about 20:1 in a devolatilization fluid bed reactor to recover devolatilized coal, gas and volatiles, (e) separating ash and impurities from said recovered devolatilized coal by burning, and (f) recycling said purified devolatilized coal for heating to produce hot char.
Dependencies are inferred from the claim text.