Claims
- 1. A method for processing a waste stream from digestion of lignocellulosic material to form useful products, comprising:
partially oxidizing the waste stream to form hot gases and molten salts; cooling the hot gases and molten salts using a quench liquor to form quenched gas and carbonate liquor; removing particles from the quenched gas to form a raw fuel gas; removing H2S from the raw fuel gas using an H2S removal process which is more selective for H2S than it is for CO2, the removing step forming a usable fuel gas and acid gases; and further processing the acid gases to form additional useful products and without reusing the acid gases in any of the aforementioned steps.
- 2. The method according to claim 1, further comprising subjecting the carbonate liquor to a causticizer to form a caustic liquor and lime mud, the lime mud comprising a suspension of calcium carbonate, and further processing the acid gases by combining the caustic liquor with the acid gases in a caustic liquor scrubber to form a tail gas and a sulfur-rich caustic liquor.
- 3. The method according to claim 2, further comprising filtering the lime mud to separate the caustic liquor from the lime mud and washing the lime mud with water to produce weak wash.
- 4. The method according to claim 3, further comprising supplying the weak wash as part of the quenching liquor for cooling of the hot gases.
- 5. The method according to claim 4, further comprising forming a condensate with dissolved fumes while removing particles from the quenched gas, and combining the condensate with dissolved fumes and the weak wash to form the quench liquor.
- 6. The method according to claim 2, further comprising calcining the lime mud in a kiln to produce calcium oxide.
- 7. The method according to claim 6, further comprising recycling the calcium oxide from the kiln to the causticizer.
- 8. The method according to claim 1, further comprising the step of recovering sulfur from the raw fuel gas as the H2S is removed from the raw fuel gas.
- 9. The method according to claim 1, further comprising processing a waste stream of black liquor.
- 10. The method according to claim 1, further comprising processing a waste stream of red liquor.
- 11. The method according to claim 1, further comprising processing a waste stream of one of alkaline, acidic, and neutral sulfite spent liquor.
- 12. The method according to claim 1, further comprising processing a waste stream of polysulfide spent liquor.
- 13. An apparatus for processing a waste stream from digestion of lignocellulosic material to form useful products, comprising:
gasifier means for partially oxidizing the waste stream to form hot gases and molten salts; quenching means, fluidically connected to the gasifier means, for cooling the hot gases and molten salts using a quench liquor to form quenched gas and carbonate liquor; particle removing means, fluidically connected to the quenching means, for removing particles from the quenched gas to form a raw fuel gas; H2S scrubbing means, fluidically connected to the particle removing means, for removing H2S from the raw fuel gas using an H2S removal process which is more selective for H2S than it is for CO2, the removing step forming usable fuel gas as one useful product, and acid gases; and means for further processing the acid gases to form additional useful products, the means for further processing only being fluidically connected to the H2S scrubbing means in a manner which permits extraction of the acid gases without reusing any of the acid gases in the quenching means.
- 14. The apparatus according to claim 13, further comprising means for providing the carbonate liquor to causticizer means to form a caustic liquor and lime mud, the lime mud comprising a suspension of calcium carbonate, said processing means including means for combining the caustic liquor with the acid gases in a caustic liquor scrubber to form a tail gas and a sulfur-rich caustic liquor.
- 15. The apparatus according to claim 14, further comprising means for filtering the lime mud to separate the caustic liquor from the lime mud and means for washing the lime mud with water to produce weak wash.
- 16. The apparatus according to claim 15, further comprising means for supplying the weak wash as part of the quenching liquor for cooling of the hot gases.
- 17. The apparatus according to claim 16, further comprising means for forming a condensate with dissolved fumes while removing particles from the quenched gas, and means for combining the condensate with dissolved fumes and the weak wash together to form the quench liquor.
- 18. The apparatus according to claim 14, further comprising means for calcining the lime mud in a kiln to produce calcium oxide.
- 19. The apparatus according to claim 18, further comprising means for recycling the calcium oxide from the kiln to the causticizer means.
- 20. The apparatus according to claim 13, further comprising means for recovering sulfur from the raw fuel gas as the H2S is removed from the raw fuel gas.
- 21. The apparatus according to claim 13, wherein the waste stream comprises black liquor.
- 22. The apparatus according to claim 13, wherein the waste stream comprises red liquor.
- 23. The apparatus according to claim 13, wherein the waste stream comprises one of alkaline, acidic, and neutral sulfite spent liquor.
- 24. The apparatus according to claim 13, wherein the waste stream comprises polysulfide spent liquor.
- 25. A method according to claim 1, wherein the removing the particles from the quenched gas further comprises subjecting the quenched gas to a multi-step fume reduction process which includes heat extraction from the quenched gas to reduce particulate load and water content of the quenched gas to form a low fume fuel gas; and wherein the usable fuel gas from the removing H2S from the low fume fuel gas using an H2S removal process forms a clean, sweet, fuel gas which is conveyed to a combustion process.
- 26. The method according to claim 25, wherein the multi-step fume reduction process comprises passing the quenched fuel gas through a first venturi scrubber, an electrostastic agglomerator, and a second venturi scrubber in series.
- 27. The method according to claim 25, further comprising subjecting the carbonate liquor to a causticizer to form a caustic liquor and lime mud, the lime mud comprising a suspension of calcium carbonate, and further processing the acid gases by combining the caustic liquor with the acid gases in a caustic liquor scrubber to form a tail gas and a sulfur-rich caustic liquor.
- 28. The method according to claim 27, further comprising filtering the lime mud to separate the caustic liquor from the lime mud and washing the lime mud with water to produce weak wash.
- 29. The method according to claim 28, further comprising supplying the weak wash as part of the quench liquor for cooling of the hot gases.
- 30. The method according claim 29, further comprising forming a condensate with dissolved fumes in the multi-step fume reduction process while removing particles from the quenched gas, and combining the condensate with dissolved fumes and the weak wash to form the quench liquor.
- 31. The method according to claim 27, further comprising calcining the lime mud in a kiln to produce calcium oxide.
- 32. The method according to claim 31, further comprising recycling the calcium oxide from the kiln to the causticizer.
- 33. The method according to claim 25, further comprising the step of recovering sulfur from the low fume fuel gas.
- 34. The method according to claim 25, further comprising processing a waste stream of black liquor.
- 35. The method according to claim 25, further comprising processing a waste stream of red liquor.
- 36. The method according to claim 25, further comprising processing a waste stream of one of alkaline, acidic, and neutral sulfite spent liquor.
- 37. The method according to claim 25, further comprising processing a waste stream of polysulfide spent liquor.
- 38. The method according to claim 25, further comprising conveying the clean, sweet, fuel gas to a combustor of a gas turbine coupled to an electric generator.
- 39. The method according to claim 38, further comprising producing hot exhaust gases in the gas turbine and conveying the hot exhaust gases to a waste heat boiler and producing steam in the waste heat boiler.
- 40. The method according to claim 39, further comprising conveying steam from the waste heat boiler to a steam turbine coupled to an electric generator.
- 41. The method according to claim 1, further comprising contacting one of hot water and steam obtained from the quenched gas as it is processed in the multi-step fume reduction process with the clean, sweet, fuel gas to increase the heat and water content of the clean, sweet, fuel gas.
- 42. The apparatus according to claim 13, wherein the particle removing means comprises a multi-step fume reduction process means for removing particles from the quenched gas to form a raw fuel gas which includes means for extracting heat and water from the quenched gas to reduce particulate load and water content of the quenched gas to form a low fume fuel gas; and wherein the usable fuel gas is a clean, sweet, fuel gas; and further comprising means for conveying the clean, sweet, fuel gas to a combustion process.
- 43. The apparatus according to claim 42, wherein the multi-step fume reduction process means comprises a first venturi scrubber, an electrostastic agglomerator, and a second venturi scrubber in series.
- 44. The apparatus according to claim 42, further comprising means for providing the carbonate liquor to causticizer means to form a caustic liquor and lime mud, the lime mud comprising a suspension of calcium carbonate, said processing means including means for combining the caustic liquor with the acid gases in a caustic liquor scrubber to form a tail gas and a sulfur-rich caustic liquor.
- 45. The apparatus according to claim 44, further comprising means for filtering the lime mud to separate the caustic liquor from the lime mud and means for washing the lime mud with water to produce weak wash.
- 46. The apparatus according to claim 45, further comprising means for supplying the weak wash as part of the quench liquor for cooling of the hot gases.
- 47. The apparatus according to claim 46, further comprising means for forming a condensate with dissolved fumes in the multi-step fame reduction process while removing particles from the quenched gas, and means for combining the condensate with dissolved fumes and the weak wash together to form the quench liquor.
- 48. The apparatus according to claim 44, further comprising means for calcining the lime mud in a kiln to produce calcium oxide.
- 49. The apparatus according to claim 48, further comprising means for recycling the calcium oxide from the kiln to the causticizer means.
- 50. The apparatus according to claim 42, further comprising means for recovering sulfur from the low fume fuel gas.
- 51. The apparatus according to claim 42, wherein the waste stream comprises black liquor.
- 52. The apparatus according to claim 42, wherein the waste stream comprises red liquor.
- 53. The apparatus according to claim 42, wherein the waste stream comprises one of alkaline, acidic, and neutral sulfite spent liquor.
- 54. The apparatus according to claim 42, wherein the waste stream comprises polysulfide spent liquor.
- 55. The apparatus according to claim 42, further comprising means for conveying the clean, sweet, fuel gas to a combustor of a gas turbine coupled to an electric generator.
- 56. The apparatus according to claim 55, wherein the gas turbine produces hot exhaust gases and comprising means for conveying the hot exhaust gases to a waste heat boiler to produce steam in the waste heat boiler.
- 57. The apparatus according to claim 56, further comprising means for conveying steam from the waste heat boiler to a steam turbine coupled to an electric generator.
- 58. The apparatus according to claim 42, further comprising means for contacting one of hot water and steam obtained from the quenched gas as it is processed in the multi-step fume reduction process with the clean, sweet, fuel gas to increase the heat and water content of the clean, sweet, fuel gas.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Reference is made to related U.S. Pat. No. 6,238,459 to William Downs (also a named co-inventor in the present application), issued May 29, 2001. U.S. Pat. No. 6,238,459 is hereby incorporated by reference as though fully set forth herein. Unless otherwise stated, definitions of terms in that patent are also valid for this disclosure.
[0002] This Continuation Application bases its priority from co-pending U.S. Ser. No. 09/284,973, filed on Apr. 23, 1999 and titled “Gasification Process for Spent Liquor at High Temperature and High Pressure.” To the extent that the parent application previously incorporated by reference now-abandoned U.S. Ser. No. 09/284,533 filed by Jerry D. Blue, William Downs, Timothy A. Fuller, and Christopher L. Verrill on Apr. 23, 1999, and titled “Sulfur Recovery From Spent Liquor Gasification Process,” the text of the U.S. Ser. No. 09/284,533 application is now explicitly included the text of this Continuation Application.
Continuations (1)
|
Number |
Date |
Country |
Parent |
09284973 |
Oct 1999 |
US |
Child |
09945927 |
Sep 2001 |
US |