Process and apparatus for the production of combustible gases

Claim 1

Apparatus for producing substantially sulphur-free combustible gas from sulphur-containing coal, comprising a reactor vessel having an upstream end and a downstream end containing a bed of particles containing at least one alkaline earth metal oxide or precursor of such oxide, a gas distributor supporting said bed, means for monitoring the bed temperature at the downstream end of the bed, means for supplying a hydrocarbon oil to the region of said downstream end, means for regulating the rate of oil supply to maintain the bed temperature at said region to which oil is supplied within the range of about 800* -1,025*C., means for supplying particulate sulphur-containing coal to said bed upstream of the region to which oil is supplied, means for supplying steam to said bed at least to regions where, during operation, devolatilized coal will be present, means responsive to the rate of supply of coal to regulate the rate of supply of steam, means for monitoring the temperature of the reactor bed, means for supplying an oxygen-containing gas underneath said distributor for fluidizing the contents of the reactor bed, means for supplying an inert gas underneath said distributor for diluting the oxygen-containing gas in the bed, first valve means for regulating the rate of supply of oxygen-containing gas, second valve means for regulating the rate of supply of said inert gas, said second valve means being responsive to the bed temperature to close the second valve means progressively as the bed temperature falls towards about 800*C., and to open the second valve means progressively as the bed temperature increases towards about 1,025*C. whereby to maintain the bed temperature between about 800*C. and about 1,025*C., means responsive to the rate of supply of gas to the reactor bed to progressively close the first valve means as the gas supply rate approaches a selected upper limit and to open the first valve means as the gas supply rate approaches a selected lower limit, whereby to maintain particles in the bed in a substantially selected state of fluidization, a regenerator vessel having an upstream end and a downstream end, a gas distributor in said regenerator vessel, means for transferring particles from a first region of the downstream end of the particle bed in the reactor vessel to a first region of the regenerator vessel at the upstream end theReof, means for transferring particles from a second region of the downstream end of the regenerator vessel to a second region of the upstream end of the reactor vessel, means responsive to the temperature of particles in the regenerator to reduce the rate of particle transfer progressively when the temperature in the regenerator increases toward about 1,150*C. and to increase the rate of particle transfer when the temperature decreases toward about 1, 000*C., means for supplying an oxygen-containing gas at a regulatable rate beneath the regenerator distributor for contact with particles above the distributor, means for monitoring at least one constituent of exhaust gases leaving the regenerator vessel, said constituent being chosen from oxygen and SO2, and means responsive to signals from the monitoring means for reducing the rate of supply of oxygen-containing gas to the regenerator vessel when the oxygen content of the exhaust gases exceeds a maximum selected concentration or the SO2 content is lower than a minimum selected concentration.

Claim 7

A METHOD OF PRODUCING A SUBSTANTIALLY SULFUR-FREE COMBUSTIBLE GAS FROM A SOLID CARBONACEOUS MATERIAL SELECTED FROM THE GROUP CONSISTING OF COAL, LIGNITE, PEAT AND SHALE AND MIXTURES THEREOF, WHICH COMPRISES REACTING SAID CARBONACEOUS MATERIAL IN THE UPSTREAM REGION OF A REACTOR BED OF FLUIDIZED PARTICLES CONTAINING AT LEAST ONE ALKALINE EARTH METAL OXIDE AT A TEMPERATURE OF BETWEEN ABOUT 800*C. AND 1,025*C. WITH AN OXYGEN-CONTAINING GAS HAVING AN OXYGEN CONTENT OF BETWEEN ABOUT 20 PERCENT AND 50 PERCENT OF THE AMOUNT REQUIRED FOR STOICHIOMETRIC COMBUSTION OF SAID CARBONACEOUS MATERIAL TO CONVERT SAID CARBONACEOUS MATERIAL TO A SUBSTANTIALLY SULFURFREE COMBUSTIBLE GAS AND COMBINING THE SULFUR IN SAID CARBONACEOUS MATERIAL WITH THE ALKALINE EARTH METAL OF SAID PARTICLES TO FORM ALKALINE EARTH METAL SULFIDES, TRANSFERRING SAID PARTICLES FROM A DOWNSTREAM REGION OF SAID REACTOR BED TO REGENERATOR BED WHEREIN SAID TRANSFERRED PARTICLES ARE REACTED AT A TEMPERATURE IN THE RANGE OF ABOUT 1000* TO 1100*C. WITH AN OXYGEN-CONTAINING GAS TO THEREBY CONVERT THE ALKALINE EARTH METAL SULFIDES TO ALKALINE EARTH METAL OXIDES WITH THE CONCURRENT EVOLUTION OF SULFUR DIOXIDE, RETURNING SAID PARTICLES FROM SAID REGENERATOR TO THE UPSTREAM REGION OF SAID REACTOR BED, INTRODUCING A HYDROCARBON OIL IN THE SAID DOWNSTREAM REGION OF SAID REACTOR BED AND INTRODUCING STEAM IN THE OXYGENCONTAINING GAS ENTERING AT LEAST UPSTREAM OF THE REGION OF SAID OIL INTRODUCTION.

Claim 8

A METHOD OF PRODUCING A SUBSTANTIALLY SULFUR-FREE COMBUSTIBLE GAS FROM A SOLID CARBONACEOUS MATERIAL SELECTED FROM THE GROUP CONSISTING OF COAL, LIGNITE, PEAT AND SHALE AND MIXTURES THEREOF, WHICH COMPRISES REACTING SAID CARBONACEOUS MATERIAL IN THE UPSTREAM REGION OF A REACTOR BED OF FLUIDIZED PARTICLES CONTAINING AT LEAST ONE ALKALINE EARTH METAL OXIDE AT A TEMPERATURE OF BETWEEN ABOUT 800*C. AND 1,025*C. WITH AN OXYGEN-CONTAINING GAS HAVING AN OXYGEN CONTENT OF BETWEEN ABOUT 20 PERCENT AND 50 PERCENT OF THE AMOUNT REQUIRED FOR STOICHIOMETRIC COMBUSTION OF SAID CARBONACEOUS MATERIAL TO CONVERT SAID CARBONACEOUS MATERIAL TO A SUBSTANTIALLY SULFURFREE COMBUSTIBLE GAS AND COMBINING THE SULFUR IN SAID CARBONACEOUS MATERIAL WITH THE ALKALINE EARTH METAL OF SAID PARTICLES TO FORM ALKALINE EARTH METAL SULFIDES, TRANSFERRING SAID PARTICLES FROM A DOWNSTREAM REGION OF SAID REACTOR BED TO REGENERATOR BED WHEREIN SAID TRANSFERRED PARTICLES ARE REACTED AT A TEMPERATURE IN THE RANGE OF ABOUT 1000* TO 1100*C. WITH AN OXYGEN-CONTAINING GAS TO THEREBY CONVERT THE ALKALINE EARTH METAL SULFIDES TO ALKALINE EARTH METAL OXIDES WITH THE CONCURRENT EVOLUTION OF SULFUR DIOXIDE, RETURNING SAID PARTICLES FROM SAID REGENERATOR TO THE UPSTREAM REGION OF SAID REACTOR BED, INTRODUCING A HYDROCARBON OIL IN THE SAID DOWNSTREAM REGION OF SAID REACTOR BED AND INTRODUCING STEAM IN THE OXYGENCONTAINING GAS ENTERING AT LEAST UPSTREAM OF THE REGION OF SAID OIL INTRODUCTION.

Claim 9

A method of producing a substantially sulfur-free combustible gas from a solid carbonaceous material selected from the group consisting of coal, lignite, peat and shale and mixtures thereof, which comprises reacting said carbonaceous material in the upstream region of a reactor bed of fluidized particles containing at least one alkaline earth metal oxide at a temperature of between about 800*C. and 1,025*C. with an oxygen-containing gas having an oxygen content of between about 20 and 50 percent of the amount required for stoichiometric combustion of said carbonaceous material to convert said carbonaceous material to a substantially sulfur-free combustible gas and combining the sulfur in said carbonaceous material with the alkaline earth metal of said particles to form alkaline earth metal sulfides, transferring said particles from a downstream region of said reactor bed to a regenerator bed wherein said transferred particles are reacted at a temperature in the range of about 1000* to 1100*C. with an oxygen-containing gas to thereby convert the alkaline earth metal sulfides to alkaline earth metal oxides with the concurrent evolution of sulfur dioxide, returning said particles from said regenerator to the upstream region of said reactor bed, introducing a hydrocarbon oil in the said downstream region of said reactor bed and introducing steam in the oxygen-containing gas entering at least upstream of the region of said oil introduction.

Claim 10

A method of producing a substantially sulfur-free combustible gas from a solid carbonaceous material selected from the group consisting of coal, lignite, peat and shale and mixtures thereof, which comprises reacting said carbonaceous material in the upstream region of a reactor bed of fluidized particles containing at least one alkaline earth metal oxide at a temperature of between about 800*C. and 1,025*C. with an oxygen-containing gas having an oxygen content of between about 20 and 50 percent of the amount required for stoichiometric combustion of said carbonaceous material to convert said carbonaceous material to a substantially sulfur-free combustible gas and combining the sulfur in said carbonaceous material with the alkaline earth metal of said particles to form alkaline earth metal sulfides, transferring said particles from a downstream region of said reactor bed to a regenerator bed wherein said transferred particles are reacted at a temperature in the range of about 1000* to 1100*C. with an oxygen-containing gas to thereby convert the alkaline earth metal sulfides to alkaline earth metal oxides with the concurrent evolution of sulfur dioxide, returning said particles from said regenerator to the upstream region of said reactor bed, introducing a hydrocarbon oil in the said downstream region of said reactor bed and introducing steam in the oxygen-containing gas entering at least upstream of the region of said oil introduction.