Process for producing a sulfur free combustible gas

Claim 2

A process for producing hot gas having 10 to 400 BTU/ft 3 content and devoid of sulfur, halogens and particulate matter comprising the steps of: I. reacting at 750° to 850°C a sulfur-bearing coal, air, steam, and, a metal compound selected from the group consisting of sodium oxide, sodium hydroxide, sodium bicarbonate, sodium carbonate and mixtures thereof, to produce sodium sulfide, wherein A. the atomic ratio of oxygen present in air to carbon in coal is between 1:1 and 1:3, and B. the atomic ratio of metal in the metal compound to sulfur in coal is not less than 2:1, Ii. reacting the sodium sulfide produced from Step I with additional coal, additional air and steam at 200° to 650°C to regenerate sodium carbonate, wherein A. the atomic ratio of carbon in coal to oxygen in air is between 1:1 and 3:1, and B. the molar ratio of the sodium sulfide to carbon in the coal is between 1:3 and 1:10.

Claim 3

A process for producing hot combustible gas with low BTU content and free of sulfur, halognes and particulate matte comprising the steps of: I. reacting in a reacting zone at 750° to 850°C a sulfur contaminated coal, air, steam, and a metal compound selected from the group consisting of sodium oxide, sodium hydroxide, sodium bicarbonate, sodium carbonate and mixtures thereof to produce sodium sulfide and sulfur-free hot combustible gas, amount of metal compound being sufficient so that substantially all of the sulfur is reacted to sodium sulfide, Ii. conveying the sodium sulfide to a second reacting zone, Iii. reacting in the second reactng zone the sodium sulfide produced in Step I with additional coal, air and steam at 200° to 650°C to produce crude hydrogen sulfide, coal ash and sodium carbonate, Iv. leaching the sodium carbonate and coal ash with water to produce sodium carbonate solution and insoluble coal ash, V. separating the sodium carbonate solution, from the insoluble coal ash, Vi. cooling the sodium carbonate solution to produce crystalline sodium carbonate and a supernatant mother liquor, Vii. recycling the crystalline sodium carbonate to Step I, and Viii. recycling the supernatant mother liquor to Step IV.

Claim 4

A process for producing hot combustible gas with low BTU content and free of sulfur, halognes and particulate matte comprising the steps of: I. reacting in a reacting zone at 750° to 850°C a sulfur contaminated coal, air, steam, and a metal compound selected from the group consisting of sodium oxide, sodium hydroxide, sodium bicarbonate, sodium carbonate and mixtures thereof to produce sodium sulfide and sulfur-free hot combustible gas, amount of metal compound being sufficient so that substantially all of the sulfur is reacted to sodium sulfide, Ii. conveying the sodium sulfide to a second reacting zone, Iii. reacting in the second reactng zone the sodium sulfide produced in Step I with additional coal, air and steam at 200° to 650°C to produce crude hydrogen sulfide, coal ash and sodium carbonate, Iv. leaching the sodium carbonate and coal ash with water to produce sodium carbonate solution and insoluble coal ash, V. separating the sodium carbonate solution, from the insoluble coal ash, Vi. cooling the sodium carbonate solution to produce crystalline sodium carbonate and a supernatant mother liquor, Vii. recycling the crystalline sodium carbonate to Step I, and Viii. recycling the supernatant mother liquor to Step IV.

Claim 5

A process for producing hot combustible gases with low BTU content and free of sulfur, halogens and particulate matter comprising the steps of: I. reacting in a first reacting zone at 750° to 850°C A. coal contaminated with sulfur, B. sodium carbonate, C. air, D. steam, E. carbon dioxide, wherein F. the atomic ratio of metal in B to sulfur in A is 2:1 to 10:1, G. the pressure of the first reacting zone is 0 to 50 psig, H. the atomic ratio of oxygen in the air to carbon in A is 1:1 to 1:5, to produce: I. sodium sulfide, J. a hot combustible gas comprising carbon monoxide and hydrogen, K. ash, Ii. conveying the sodium sulfide and ash to a second reacting zone, Iii. reacting at 200° to 650°C in the second reacting zone A. sodium sulfide and ash from Step I, B. additional coal, C. air, D. steam, wherein: E. the pressure of the second reacting zone is 0 to 150 psig, F. the molar ratio of A to carbon in B is 1:3 to 1:10, G. the atomic ratio of oxygen in air to carbon in coal is 1:1 to 3:1, H. crude hydrogen sulfide, I. sodium carbonate, J. ash, Iv. removing the crude hydrogen sulfide, V. leaching the solid sodium carbonate and insoluble ash with water at 25° to 100°C to produce: A. sodium carbonate solution, B. ash, Vi. separating the sodium carbonate solution from the ash Vii. crystallizing the sodium carbonate solution from Step VI by cooling at 0° to 40°C to produce: A. crystalline sodium carbonate, and B. supernatant mother liquor, Viii. recycling the crystalline sodium carbonate from Step VII to Step I, and Ix. recycling and supernatant mother liquor from Step VII to Step V.

Claim 6

A process for producing hot combustible gases with low BTU content and free of sulfur, halogens and particulate matter comprising the steps of: I. reacting in a first reacting zone at 750° to 850°C A. coal contaminated with sulfur, B. sodium carbonate, C. air, D. steam, E. carbon dioxide, wherein F. the atomic ratio of metal in B to sulfur in A is 2:1 to 10:1, G. the pressure of the first reacting zone is 0 to 50 psig, H. the atomic ratio of oxygen in the air to carbon in A is 1:1 to 1:5, to produce: I. sodium sulfide, J. a hot combustible gas comprising carbon monoxide and hydrogen, K. ash, Ii. conveying the sodium sulfide and ash to a second reacting zone, Iii. reacting at 200° to 650°C in the second reacting zone A. sodium sulfide and ash from Step I, B. additional coal, C. air, D. steam, wherein: E. the pressure of the second reacting zone is 0 to 150 psig, F. the molar ratio of A to carbon in B is 1:3 to 1:10, G. the atomic ratio of oxygen in air to carbon in coal is 1:1 to 3:1, H. crude hydrogen sulfide, I. sodium carbonate, J. ash, Iv. removing the crude hydrogen sulfide, V. leaching the solid sodium carbonate and insoluble ash with water at 25° to 100°C to produce: A. sodium carbonate solution, B. ash, Vi. separating the sodium carbonate solution from the ash Vii. crystallizing the sodium carbonate solution from Step VI by cooling at 0° to 40°C to produce: A. crystalline sodium carbonate, and B. supernatant mother liquor, Viii. recycling the crystalline sodium carbonate from Step VII to Step I, and Ix. recycling and supernatant mother liquor from Step VII to Step V.

Claim 7

The process of claim 1 wherein the molar ratio of carbon dioxide to the carbon in the coal is between 1:50 and 1:200.