Claims
- 1. A continuous process for the production of desulfurized synthesis gas, fuel gas, or reducing gas comprising:
- (1) reacting a first portion of sulfur-containing heavy liquid hydrocarbonaceous fuel and/or sulfure-containing solid carbonaceous fuel containing about 0.2 to 8.0 wt. % sulfur by partial oxidation with controlled amounts of free-oxygen containing gas and temperature moderator in a first free-flow refractory lined reaction zone of a gas generator at an autogenous temperature in the range of about 1900.degree. F. to 2900.degree. F. and a pressure in the range of about 2 to 250 atmospheres so that an equilibrium oxygen concentration with a partial pressure which is less than about 10.sup.-12 atmospheres is provided in the gas phase in said first reaction zone and in a downstream second reaction zone; and in said first reaction zone the O/C atomic ratio is in the range of about 0.3 to 1.1, the weight ratio of water to solid carbonaceous fuel plus liquid hydrocarbonaceous material, if any, is in the range of about 0.03 to 0.70, and about 70 to 98 wt. % of the carbon in said sulfur-containing fuel is converted into carbon oxides, thereby producing a hot gas stream including a raw product gas mixture comprising H.sub.2, CO, CO.sub.2, H.sub.2 S, COS, at least one gas selected from the group consisting of H.sub.2 O, N.sub.2, CH.sub.4, and A, and entrained material comprising particulate carbon, unreacted fuel if any, and molten slag; and the temperature is above the softening temperature of the ash in the fuel, and at least 90 wt. % of the sulfur in the fuel in the first reaction zone is converted into sulfur-containing gas;
- (2) passing at least a portion of the hot gas stream from (1) in admixture with a second portion of said sulfur-containing fuel and a calcium-containing additive through a second unobstructed free-flow refractory lined reaction zone, wherein sufficient calcium-containing additive is introduced into the second reaction zone so as to provide calcium atoms in the amount of about 0.95 to 1.8 times the atoms of sulfur in the second reaction zone plus about 0.1 to 0.2 times the atoms of silicon in the ash in the second reaction zone, and the mole ratio of H.sub.2 O and/or CO.sub.2 to carbon in the second reaction zone is in the range of about 0.7 to 25;
- (3) devolatilizing said second portion of sulfur-containing fuel and reacting in said second reaction zone in the absence of additional free-oxygen containing gas at a temperature below that in said first reaction zone and below the ash softening temperature, (i) H.sub.2 O and/or CO.sub.2 with carbon from said second portion of fuel, and carbon from the unreacted portion of said first portion of fuel, if any, to produce supplemental H.sub.2 and carbon oxides, and (ii) said calcium-containing additive with the sulfur containing gases in the gas streams produced in steps (1) and (2) to produce particulate matter comprising calcium sulfide and combining in said second reaction zone a portion of said newly formed particulate matter and/or calcium-containing additive with slag and/or ash to produce fly-ash having an increased ash softening temperature; and
- (4) discharging from said second reaction zone a stream of synthesis gas, reducing gas, or fuel gas with entrained fly-ash and in comparison with a gas stream produced without the introduction of said calcium-containing additive in (2), the gas stream discharged from the second reaction zone contains a reduced amount of sulfur-containing gases, and increased amounts of H.sub.2 + carbon oxides and calcium sulfide-containing particulate matter.
- 2. The process of claim 1 wherein said calcium-containing additive is introduced into the hot gas stream from (1) at the entrance to and/or at one or more locations within the second reaction zone.
- 3. The process of claim 1 provided with the step of contacting the hot gas stream passing through the central passage of said second reaction zone with an atomized spray of said calcium-containing additive.
- 4. The process of claim 1 provided with the step of separating at least a portion of the fly-ash from the gas stream in (4).
- 5. The process of claim 1 wherein the calcium-containing additive in (2) comprises an inorganic or an organic calcium compound.
- 6. The process of claim 1 wherein the said calcium-containing additive in (2) is an organic calcium compound selected from the group consisting of formate, oxalate, acetate, stearate, benzoate, tartrate, and mixtures thereof.
- 7. The process of claim 1 wherein the said calcium-containing additive is selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, calcium hydride, calcium nitrate, calcium phosphate, and mixtures thereof.
- 8. The process of claim 1 wherein the dwell times in the first and second reaction zones in (1) and (2) are respectively in the ranges of about 0.5-10 seconds and about 5 to 50 seconds.
- 9. The process of claim 1 wherein the hot stream of gas leaving the first reaction zone in (1) is introduced into the second reaction zone in (2) with substantially no change in temperature and pressure, except for ordinary losses of temperature and pressure in the lines.
- 10. The process of claim 1 wherein at least a portion of the entrained material and slag in the hot gas stream leaving the gas generator in (1) are removed respectively by gas-solids separation means and gravity prior to introducing the hot gas stream into the second reaction zone in (2).
- 11. The process of claim 1 wherein said sulfur-containing solid carbonaceous fuel is selected from the group consisting of coal, coke from coal; lignite; residue derived from coal liquefaction; oil shale; tar sands; petroleum coke; asphalt; pitch; particulate carbon (soot); and mixtures thereof.
- 12. The process of claim 1 wherein the calcium-containing additive in (2) is introduced into said second reaction zone at one or more levels between the top and bottom of said reaction zone.
- 13. The process of claim 1 wherein said sulfur-containing solid carbonaceous fuel is introduced into said second reaction zone in (2) entrained in a liquid or gaseous carrier.
- 14. The process of claim 13 wherein said liquid carrier is selected from the group consisting of water, liquid hydrocarbonaceous fuel, and mixtures thereof.
- 15. The process of claim 13 wherein said gaseous carrier is selected from the group consisting of steam, air, N.sub.2, CO.sub.2, recycle synthesis gas, and mixtures thereof.
- 16. The process of claim 1 in which said temperature moderator is selected from the group consisting of steam, water, CO.sub.2 -rich gas, liquid CO.sub.2, N.sub.2, recycle synthesis gas, exhaust gas from a turbine, and mixtures thereof.
- 17. The process of claim 1 in which said free-oxygen containing gas is selected from the group consisting of air, oxygen-enriched air, i.e. greater than 21 mole % O.sub.2, and substantially pure oxygen, i. e. greater than about 95 mole % O.sub.2.
- 18. The process of claim 1 wherein said mixture of solid carbonaceous fuel and calcium-containing additive is introduced downwardly into said second reaction zone entrained in a gaseous or liquid mixture.
- 19. The process of claim 1 wherein said solid carbonaceous fuel and supplemental calcium-containing material is introduced into the second reaction zone as a slurry in a liquid hydrocarbonaceous fuel.
- 20. The process of claim 1 where in (2) said second portion of sulfur-containing fuel comprises a pumpable slurry of solid carbonaceous fuel and calcium-containing material having a solids content of about 50-70 wt. % in a liquid carrier selected from the group consisting of H.sub.2 O and CO.sub.2 ; and provided with the step of skimming said liquid carrier prior to said mixture entering the second reaction zone to reduce the amount of H.sub.2 O entering the second reaction zone to about 5 to 10 wt. % (basis weight of feed), or alternatively to reduce the amount of CO.sub.2 entering the second reaction zone to about 10 to 30 wt. % (basis weight of feed).
- 21. The process of claim 1 provided with the steps of cooling and cleaning, the hot raw product gas mixture in (2) by contacting said raw product gas mixture with a liquid hydrocarbonaceous fuel cooling and scrubbing agent thereby producing a slurry comprising fly-ash and calcium sulfide in liquid hydrocarbonaceous fuel.
- 22. The process of claim 21 provided with the steps of steam stripping said slurry comprising fly-ash and calcium sulfide in liquid hydrocarbonaceous fuel and separating H.sub.2 S, and recycling the sulfur-depleted calcium-containing slurry to the second reaction zone.
- 23. The process of claim 22 provided with the step of recovering sulfur from the mixture of steam and H.sub.2 S.
- 24. The process of claim 1 provided with the step of cooling the hot gas stream from (4) by indirect heat exchange thereby producing by-product steam.
- 25. The process of claim 1 provided with the steps of separating particulate matter comprising calcium sulfide and particulate carbon from the partially cooled gas stream in a gas-solids separation zone, roasting said particulate matter thereby substantially producing calcium oxide and sulfurcontaining gas, and separating said calcium oxide from said sulfur-containing gas.
- 26. The process of claim 25 provided with the step of introducing a portion of said calcium oxide in admixture with make-up calcium-containing additive entrained in a carrier into the second reaction zone in (2), where said materials are mixed with said hot gas stream from (1).
- 27. The process of claim 25 provided with the step of introducing a portion of said calcium oxide into said partial oxidation reaction zone in (1) in admixture with said heavy liquid hydrocarbonaceous and/or solid carbonaceous fuel.
- 28. The process of claim 25 provided with the step of classifying said particulate matter prior to said roasting step and separating out materials having a particle size greater than about 100 microns.
- 29. The process of claim 28 provided with the step of mixing said materials having a particle size greater than about 100 microns with a second portion of said sulfur-containing heavy liquid hydrocarbonaceous fuel feed and/or sulfur containing solid carbonaceous fuel feed and introducing at least a portion of said mixture into the second reaction zone.
- 30. The process of claim 1 wherein the hot process gas stream from (1) is passed either in a downward or upward direction through said first and second reaction zones.
- 31. The process of claim 1 wherein said first and second reaction zones are coaxial and horizontally oriented.
- 32. The process of claim 1 wherein the hot gas stream from (1) is contacted in said second reaction zone with at least one atomized spray of calcium-containing additive at and/or beyond the entrance of said second reaction zone.
- 33. The process of claim 1 wherein an alkali metal and/or an alkaline earth metal compound is introduced into the second reaction zone in (2) in admixture with said calcium-containing additive and said second portion of fuel.
- 34. The process of claim 33 wherein said alkali metal and/or alkaline earth metal constituents are selected from the metals in the Periodic Table of Elements in Groups IA and/or IIA.
- 35. A continuous process for the production of desulfurized synthesis gas, fuel gas, or reducing gas comprising:
- (1) mixing a first portion of sulfur-containing heavy liquid hydrocarbonaceous fuel and/or sulfur-containig solid carbonaceous fuel whose ashes include a minimum of 5.0 wt. % vanadium, a minimum of 2.0 wt. % of nickel, and silicon with additive A comprising an iron-containing additive when the silicon content of said fuel feedstock is less than about 350 ppm, additive B comprising an iron and calcium-containing additive when the silicon content of said fuel feedstock is about 400 ppm or more; and reacting said mixture by partial oxidation with a free-oxygen containing gas and in the presence of a temperature moderator in a first free-flow refractory lined reaction zone of a gas generator at an autogeneous temperature in the range of about 1900.degree. F. to 2900.degree. F. and above the softening temperature of the ash in the first reaction zone, and a pressure in the range of about 2 to 250 atmospheres to produce a hot stream of synthesis gas, reducing gas, or fuel gas comprising H.sub.2, CO, CO.sub.2, H.sub.2 S, COS and at least one gaseous material selected from the group consisting of H.sub.2 O, N.sub.2, CH.sub.4, NH.sub.3, A, and containing entrained material comprising particulate carbon, unreacted fuel if any, and slag, wherein sufficient additive A or B is introduced into the first reaction zone so as to provide iron atoms when additive A is used or iron and calcium atoms when additive B is used in the amount of about 1.0 to 1.8 times the atoms of sulfur in the first reaction zone plus about 0.3 to 1.2 times the atoms of silicon in the ash in the second reaction zone; and for each part by weight of vanadium there is at least 10 parts by weight of iron when additive A is used, or at least 10 parts by weight of iron and calcium when additive B is used;
- (2) passing at least a portion of the hot gas stream from (1) in admixture with a second portion of said sulfur-containing heavy liquid hydrocarbonaceous fuel and/or sulfur-containing solid carbonaceous fuel and a calcium-containing additive through a second unobstructed free-flow refractory lined reaction zone; wherein sufficient calcium-containing additive is introduced into the second reaction zone so as to provide calcium atoms in the amount of about 0.95 to 1.8 times the atoms of sulfur in the second reaction zone plus about 0.1 to 0.2 times the atoms of silicon in the ash from said second portion of sulfur-containing fuel, and the mole ratio of H.sub.2 O and/or CO.sub.2 to carbon in the second reaction zone is in the range of about 0.7 to 25.0; and the weight ratio of calcium-containing additive to ash in the second reaction zone is in the range of about 1.0-10.0 to 1.0;
- (3) devolatilizing said second portion of sulfur-containing fuel and reacting in said second reaction zone in the absence of additional free-oxygen containing gas; and at a temperature below that in said first reaction zone and below the ash softening temperature, (i) H.sub.2 O and/or CO.sub.2 with carbon from said second portion of fuel, to produce supplemental H.sub.2 and carbon oxides, and (ii) said calcium-containing additive with the sulfur containing gases in the gas streams produced in steps (1) and (2) to produce particulate matter comprising calcium sulfide and combining in said second reaction zone a portion of said newly formed particulate matter and/or calcium-containing additive with slag and/or ash to produce fly-ash having a reduced ash softening temperature; and
- (4) discharging from said second reaction zone a stream of synthesis gas, reducing gas, or fuel gas with entrained fly-ash; and in comparison with a gas stream produced without the introduction of said calcium-containing additive in (2), the gas stream discharged from the second reaction zone contains a reduced amount of sulfur-containing gases, and increased amounts of H.sub.2 + carbon oxides and calcium sulfide-containing particulate matter.
- 36. The process of claim 35 wherein said iron-containing additive A contains iron compounds selected from the group consisting of oxides, carbonates, carbonyl, nitrates, and mixtures thereof.
- 37. The process of claim 35 wherein said additive B contains iron and calcium compounds selected from the group consisting of oxides, carbonates, nitrates, and mixtures thereof.
- 38. The process of claim 35 wherein said calcium-containing additive is selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, calcium hydride, calcium nitrate, calcium phosphate, and mixtures thereof.
- 39. The process of claim 35 provided with the step of removing at least a portion of the molten slag entrained in the effluent gas stream from the first reaction zone prior to the second reaction zone
Parent Case Info
This application is a continuation-in-part of application Ser. No. 07/101,519 filed Sept. 28, 1987.
US Referenced Citations (7)
Continuation in Parts (1)
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101519 |
Sep 1987 |
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