Solid fuel preparation method

• US 4,280,817 A
• Filed: 06/25/1980
• Issued: 07/28/1981
• Est. Priority Date: 10/10/1978
• Status: Expired due to Term

• Current Assignee: Battelle Development Corporation
• Original Assignee: Battelle Development Corporation
• Inventors: Chauhan, Satya P., Stambaugh, Edgel P., Feldmann, Herman F., Liu, Ke-Tien
• Primary Examiner(s): DEES, CARL
• Application Number:
  US06/162,979
• Time in Patent Office: 398 Days
• Field of Search: 44/1 SR, 44/1 R, 44/1 F, 201/17
• US Class Current: 44/604
• CPC Class Codes: C10J 2300/0906 Physical processes, e.g. shredding, comminuting, chopping, sorting
• CPC Class Codes: C10J 2300/0909 Drying
• CPC Class Codes: C10J 2300/093 Coal
• CPC Class Codes: C10J 2300/0943 Coke
• CPC Class Codes: C10J 2300/0946 Waste, e.g. MSW, tires, glass, tar sand, peat, paper, lignite, oil shale
• CPC Class Codes: C10J 2300/0959 Oxygen
• CPC Class Codes: C10J 2300/0973 Water
• CPC Class Codes: C10J 2300/0976 as steam
• CPC Class Codes: C10J 2300/0996 Calcium-containing inorganic materials, e.g. lime
• CPC Class Codes: C10J 3/00 Production of combustible gases containing carbon monoxide from solid carbonaceous fuels destructive distillation processes C10B
• CPC Class Codes: C10J 3/56 Apparatus; Plants
• CPC Class Codes: C10J 3/723 Controlling or regulating the gasification process
• CPC Class Codes: C10L 9/02 by chemical means
• CPC Class Codes: C10L 9/10 by using additives
• CPC Class Codes: Y10S 44/905 Method involving added catalyst

Abstract

A process for treating solid particles (66) of a raw carbonaceous fuel (62) such as coal having an original sulfur content comprises producing (at 68) a slurry (74) of a quantity of the raw fuel particles and a liquid medium (70) comprising water, at least one alkali metal compound including a substantial amount of sodium or potassium sulfide or polysulfide or a combination thereof, and a catalytic agent (72) comprising calcium or magnesium oxide or carbonate, or dolomite. The slurry is subjected (in 78) for an effective period of time to elevated temperature and pressure effective with the alkali metal compounds and water to cause the medium to penetrate the microscopic structure of the particles and to chemically and physically incorporate a substantial amount of the catalytic agent into the structure. The readily separable medium is separated (at 84) from the fuel particles and the particles are washed (at 84,106) to produce a particulate fuel product (88,110) containing the incorporated catalytic agent. A substantial portion (90,94) of the separated medium is added (at 70) to the slurry produced as above. A sufficient quantity of the catalytic agent is added (at 72) to the medium or the slurry to replace the catalytic agent removed from the slurry with the particulate fuel product. More raw fuel particles (66) are added to the medium or the slurry. The foregoing steps are carried out continually with a multiplicity of new additions of the raw fuel particles and with a multiplicity of reuses of the separated medium to produce fuel product particles (88,110) containing a quantity of sulfur that is not less than the original sulfur content, in addition to the catalytic agent.

Claims

1. A process for treating solid particles of a raw carbonaceous fuel of the coal or coke type having an original sulfur content, comprising

(a) producing a slurry of a quantity of the raw fuel particles and a liquid medium comprising water, at least one alkali metal compound including a substantial amount of sodium or potassium sulfide or polysulfide or a combination thereof, and a chemical agent comprising calcium or magnesium oxide or carbonate, or dolomite,

(b) subjecting the slurry for an effective period of time to elevated temperature and pressure effective with the alkali metal compounds and water to cause the medium to penetrate the microscopic structure of the particles and to chemically and physically incorporate a substantial amount of the chemical agent into the structure,

(c) separating the readily separable medium from the fuel particles and washing the particles to remove most of the alkali metal therefrom while producing a particulate fuel product containing a substantial amount of the chemical agent therein,

(d) adding most of the separated medium to the slurry produced in step (a),

(e) adding to the medium or the slurry a sufficient quantity of the chemical agent to replace the chemical agent removed from the slurry with the particulate fuel product,

(f) adding more raw fuel particles to the medium or the slurry, and

(g) continuing to carry out steps (b-f) with a multiplicity of new additions of the raw fuel particles and with a multiplicity of reuses of the separated medium to produce fuel product particles containing a quantity of sulfur that is not substantially less than the original sulfur content, in addition to the chemical agent.

2. A process as in claim 1, wherein a multiplicity of new additions of the raw fuel particles and a multiplicity of reuses of the separated medium are carried out while the process is in a substantially steady state.

3. A process as in claim 2, wherein the concentration of sulfur in the medium remains substantially constant in the steady state process.

4. A process as in claim 1, wherein an alkali metal sulfide is added to the medium in order to replace the portion of the alkali metal retained in the fuel product particles.

5. A process as in claim 1, wherein an alkali metal hydroxide is added to the medium in order to replace the portion of the alkali metal retained in the fuel product particles.

6. A process as in claim 3, 4, or 5, wherein the medium is purged to maintain the process in a steady state with a desired concentration of at least one constituent or combination of constituents in the medium.

7. A process as in claim 1, wherein the alkali metal compounds also comprise hydroxides.

8. A process as in claim 7, wherein the mole percent of the total alkali metal in the medium that is in the sulfide or polysulfide form is at least about 15.

9. A process as in claim 1, wherein oxygen is substantially excluded from the medium to inhibit the formation of sulfites or sulfates therein.

10. A process as in claim 9, wherein the process is at least partially carried out in a substantially inert atmosphere.

11. A process as in claim 10, wherein the atmosphere is enriched with nitrogen.

12. A process as in claim 1, wherein the ratio of the chemical agent to the coal in the slurry is about 0.03 to 0.10 by weight.

13. A process as in claim 1, wherein the ratio of the sulfide compound to water is about 0.01 to 0.1 by weight.

14. A process as in claim 13, wherein the ratio of water to coal is about 1 to 2 by weight.

15. A process as in claim 14, wherein the ratio of the chemical agent to the coal is about 0.03 to 0.10 by weight.