Gasification of black liquor

Patent · Tue Jul 28 04:00:00 EDT 1987

OSTI ID:6193388

Kohl, A L

A process is described for treating a concentrated aqueous black liquor carbonaceous material and alkali metal sulfur compounds to form a combustible gas and a sulfide-rich melt comprising: (a) providing a gasifier vessel maintained at a pressure of from about 1 to 50 atmospheres and containing a relatively shallow molten salt pool at its bottom within a sump equipped with an overflow discharge; (b) introducing into the top of the drying zone the concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds; (c) evaporating water from the concentrated aqueous black liquor in the drying zone by direct contact of the aqueous black liquor with the hot gas rising from the gasification zone to produce dried black liquor solids; (d) introducing a first portion of an oxygen-containing gas into the gas space in the gasification zone located below the drying zone immediately above the molten salt pool to partially oxidize and gasify a fraction of the carbonaceous material in the dried black liquor solids falling through the zone to form a hot combustible gas; (e) introducing a second portion of the oxygen-containing gas beneath the surface of the molten salt pool in an amount sufficient to cause gasification of essentially all carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool; (f) withdrawing the cooled combustible gas having a higher heating value of at least about 90 Btu/scf (dry basis) from an upper portion of the drying zone; and (g) withdrawing from the overflow discharge in the molten salt reduction zone a melt in which the sulfur content is predominantly in the form of alkali metal sulfide.

• Assignee: Rockwell International Corp., El Segundo, CA
• Patent Number(s): US 4682985
• OSTI ID: 6193388
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKALI METAL COMPOUNDS
AQUEOUS SOLUTIONS
BLACK LIQUIDS
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
CHEMICAL REACTORS
CONTAINERS
DISPERSIONS
DRYING
ELEMENTS
EVAPORATION
FLUIDS
GASES
GASIFICATION
HYDROGEN COMPOUNDS
LIQUIDS
MATERIALS
MEDIUM PRESSURE
MELTING POINTS
MIXTURES
MOLTEN SALTS
NONMETALS
OXIDATION
OXYGEN
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
QUANTITY RATIO
SALTS
SOLUTIONS
SULFUR COMPOUNDS
THERMOCHEMICAL PROCESSES
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
VAPORS
WATER
WATER VAPOR