Patent ID: 6332949
Filing Date: 2001-12-25
Classification: C01B,Y10S

Abstract:
A process for concentrating spent sulfuric acid comprisinga) feeding spent sulfuric acid to an evaporator,b) heating the spent sulfuric acid to a temperature that is sufficient to cause evaporation of water under subatmospheric pressure and to form a gas phase, which is loaded with water vapor and additionally contains sulfuric acid, and to form a concentrated bottom product,c) bringing the gas phase above the bottom product into contact with an aqueous phase that is provided at a rate that ranges from about 10 to about 1000 kg/hour of aqueous phase, per 1000 kg/hour of vapors, wherein the sulfuric acid contained in the gas phase is absorbed by the aqueous phase and a second gas phase, which is substantially free from sulfuric acid is obtained, and wherein the aqueous phase is provided by injection into the gas phase below a demister in co-current flow with the gas phase, andd) returning the aqueous phase from c), which contains sulfuric acid, to the bottom in the form of drops which are formed on a demister which is mounted above the bottom.