Process and apparatus for recovery of spent pulping liquors
AssigneeInternational Paper Company
InventorsSalvatore T. DiNovo, Wayne E. Ballantyne
Life of this patent
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Abstract
An integrated system, process and apparatus are provided for the efficient and effective recovery of spent pulping liquors, particularly kraft black liquor, whereby in an initial stage concentrated spent liquor is subjected to combustion in a reactor equipped with a plurality of particulate materials, at least one of which is of finer particle size than the other, preferably subjecting a portion of said particulate materials to at least one further treatment in a fluidized bed unit, and treating the inorganic solid combustion products in a reducing atmosphere.
Claims42
An integrated process for the recovery of the energy and chemical values from spent pulping liquors, comprising an initial stage of subjecting concentrated spent pulping liquor to combustion with air in a fluidized bed reaction chamber provided with a plurality of solid particulate materials, at least one of which is of finer particle size than another, followed by separation of the finer particle size particulate material from the gaseous and solid combustion products outside of said initial fluidized bed reaction chamber, followed by at least one further step of treating the separated finer particle size particulate material in an external fluidized bed unit to remove heat values from the separated finer particle size particulate material and followed by return of the separated finer particle size particulate material to said initial fluidized bed reaction chamber.
An integrated process for the recovery of the energy and chemical values from spent pulping liquors, comprising an initial stage of subjecting concentrated spent pulping liquor to combustion with air in a fluidized bed reaction chamber provided with a plurality of solid particulate materials, at least one of which is of finer particle size than another, followed by separation of the finer particle size particulate material from the gaseous and solid combustion products outside of said initial fluidized bed reaction chamber, and followed by regeneration of the pulping chemicals of the spent pulping liquor from the solid combustion products and return of the separated finer particle size particulate material to said initial fluidized bed reaction chamber.
An integrated process for the recovery of the energy and chemical values from spent pulping liquors, comprising an initial stage of subjecting concentrated spent pulping liquor to combustion with air in a fluidized bed reaction chamber provided with a plurality of solid particulate materials, at least one of which is of finer particle size than another, said air being introduced at sufficient velocity to provide removal of the combustion products and the finer particle size particulate material from the upper portion of said initial fluidized bed reaction chamber, separating at least some of the entrained finer particle size particulate material from the gaseous and solid combustion products, returning at least some of the finer particle size particulate material to said initial fluidized bed reaction chamber, and subjecting a portion of the inorganic solid combustion products to chemical reduction, after which the chemically reduced inorganic solid products are dissolved in water.
An integrated process for the recovery of the energy and chemical values from spent pulping liquors, comprising the steps of:
- (a) subjecting concentrated spent pulping liquor to combustion with air in a fluidized bed reaction chamber provided with a plurality of inert solid particulate materials substantially inert to the reactions occurring in said combustion, said inert solid particulate materials containing at least one fraction of finer particle size than the other, said air being introduced at sufficient velocity to provide removal of the combustion products and the finer particle size fraction of the inert solid particulate materials from the upper portion of said fluidized bed reaction chamber,
- (b) substantially separating the gaseous and solid combustion products from the finer particle size fraction of the inert solid particulate materials,
- (c) returning the thus separated inert solid particulate material to the initial fluidized bed reaction chamber after first subjecting these solids to a further treatment in a second fluidized bed unit in an external heat exchange operation,
- (d) subjecting the gaseous and solid combustion products of (b) above to a further separation of the gaseous and solid components,
- (e) subjecting the solid component of the separated combustion products of (d) above to a chemical reduction,
- (f) passing the gaseous component of the combustion products in (d) above and the gaseous component of the reduction step in (e) above through an external heat exchange operation so as to recover the heating value of these components,
- (g) dissolving the chemically reduced inorganic solid products of step (e) in water.
An integrated system for the recovery of the energy and chemical values from spent pulping liquors, comprising in sequence and combination:
- an initial fluidized bed reaction chamber provided with means for combusting concentrated spent pulping liquor with air and a plurality of solid particulate materials, at least one of which is of finer particle size than another;
- means for separating the finer particle size particulate material from the gaseous and solid combustion products outside of said initial fluidized bed reaction chamber;
- means for returning the separated finer particle size particulate material to said initial fluidized bed reaction chamber;
- and chemical means for reducing at least a portion of the solid combustion products of said initial fluidized bed reaction chamber by action of a reducing gas in a molten inorganic salt mass which comprises the solid combustion products of said initial fluidized bed reaction chamber.
An integrated apparatus for use in the recovery of the energy and chemical values from spent pulping liquors, comprising in combination:
- an initial fluidized bed reaction chamber provided with means for combusting concentrated spent pulping liquor with air and a plurality of solid particulate materials, at least one of which is of finer particle size than another;
- means for separating the finer particle size particulate material from the gaseous and solid combustion products outside of said initial fluidized bed reaction chamber;
- means for returning the separated finer particle size particulate material to said initial fluidized bed reaction chamber;
- and chemical means for reducing at least a portion of the solid combustion products of said initial fluidized bed reaction chamber by action of a reducing gas in a molten inorganic salt mass which comprises the solid combustion products of said initial fluidized bed reaction chamber.
An integrated process for the recovery of the energy and chemical values from spent pulping liquors, comprising the steps of:
- (a) subjecting concentrated spent pulping liquor to combustion with air in a fluidized bed reaction chamber provided with a plurality of solid particulate materials, said solid particulate materials containing at least one fraction of finer particle size than the other, said air being introduced at sufficient velocity to provide removal of the combustion products and the finer particle size fraction of the solid particulate materials from the upper portion of said fluidized bed reaction chamber,
- (b) substantially separating the gaseous and solid combustion products from the finer particle size fraction of the solid particulate materials,
- (c) returning the thus separated solid particulate material to the initial fluidized bed reaction chamber after first subjecting these solids to a further treatment in a second fluidized bed unit in an external heat exchange operation,
- (d) subjecting the gaseous and solid combustion products of (b) above to a further separation of the gaseous and solid components,
- (e) subjecting the said solid component of the separated combustion products of (d) above to a chemical reduction,
- (f) passing the gaseous component of the combustion products in (d) above and the gaseous component of the reduction step in (e) above through an external heat exchange operation so as to recover the heating value of these components, and
- (g) dissolving the chemically reduced inorganic solid products of step (e) in water.
Dependencies are inferred from the claim text.