Minimizing evaporator scaling and recovery of salts during gasification
AssigneeTexaco Inc.
InventorsGeorge Henry Webster, Jr., Byron Von Klock, Dinh-Cuong Vuong, John Saunders Stevenson, Steven Robert Johnson
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Abstract
A process for minimizing evaporator scaling during the recovery of liquids and solids from the aqueous effluent discharged during a partial oxidation gasification, wherein the aqueous effluent contains ammonium chloride (NH.sub.4 Cl). The aqueous effluent is evaporated to produce a distillate water and a brine having an NH.sub.4 Cl concentration of about 10 to 60 weight percent. The brine can be further concentrated and ammonium chloride crystals are recovered. The distillate water is recycled to the gasification reaction. No effluent discharges to the environment.
Claims22
A process for minimizing evaporator scaling and for recovering water and salts from an aqueous effluent containing ammonium chloride that is formed during the partial oxidation gasification of a hydrocarbonaceous feedstock to produce a synthesis gas, comprising:
- (a) scrubbing the synthesis gas with water at a pH of at least about 6.0, wherein said pH is maintained with ammonia;
- (b) separating the synthesis gas from the scrubbing water;
- (c) separating a portion of the scrubbing water to form an aqueous effluent which is introduced to an evaporation system;
- (d) evaporating the aqueous effluent to produce water vapor and a brine having an ammonium chloride concentration of about 10 to about 60 weight percent;
- (e) separating the water vapor from the brine;
- (f) condensing the water vapor to form a distillate water;
- (g) recycling the distillate water to the partial oxidation gasification;
- (h) recovering the ammonium chloride from the brine;
- and
- (i) operating the evaporator at conditions that minimize evaporator scaling.
Dependencies are inferred from the claim text.