Acid gas treatment

Abstract

Apparatus and methods for treating acid gas, which utilizes multi-stage absorption cycle of ammonia desulfurization to treat acid tail gas after pre-treatment of the acid gas, thereby achieving the purpose of efficient and low-cost treatment of acid tail gas. The parameters of the acid tail gas may be adjusted by a regulatory system such that the enthalpy value of the acid tail gas is in the range of 60-850 kJ/kg dry gas, for example, 80-680 kJ/kg dry gas or 100-450 kJ/kg dry gas, to meet the requirements of ammonia desulfurization, and achieve the synergy between the acid gas pre-treatment and ammonia desulfurization. Furthermore, hydrogen sulfide may be converted into sulfur/sulfuric acid plus ammonium sulfate at an adjustable ratio.

1 - 54 . (canceled) 
     
     
         55 . A method for treating acid gas, the method comprising:
 receiving acid gas having an elementary sulfur and hydrogen sulfide content that is not greater than 30 ppm;   regulating an enthalpy value of the acid gas to 66-850 kJ/kg dry acid gas; and, then,   deriving from the acid gas:
 ammonium sulfate; and 
 net tail gas that has a sulfur dioxide content no greater than 400 mg/m 3 . 
   
     
     
         56 - 57 . (canceled) 
     
     
         58 . The method of  claim 55  wherein the deriving includes:
 recovering sulfur from the acid gas to produce sulfur-recovered tail gas; and, then, 
 incinerating the sulfur-recovered tail gas. 
 
     
     
         59 . The method of  claim 55  wherein the deriving includes producing sulfuric acid from the acid gas. 
     
     
         60 . The method of  claim 55  wherein the deriving includes incinerating. 
     
     
         61 . The method of  claim 55  further comprising channeling the acid gas from a petrochemical chemical reaction. 
     
     
         62 . The method of  claim 55  further comprising channeling the acid gas from a natural gas chemical reaction. 
     
     
         63 . The method of  claim 55  further comprising channeling the acid gas from a coal chemical reaction. 
     
     
         64 . The method of  claim 55  wherein:
 the deriving includes generating catalytic cracking regeneration flue gas; and 
 the acid gas includes the catalytic cracking regeneration flue gas. 
 
     
     
         65 . The method of  claim 55  wherein the deriving comprises adjusting an enthalpy value of acid gas. 
     
     
         66 . The method of  claim 55  wherein the deriving includes passing adjusted tail gas formed in the regulatory system through:
 a cooling stage, 
 an absorption stage, and 
 a water-washing stage, 
 
       all in an ammonia circulation desulfurization reactor. 
     
     
         67 . The method of  claim 65  wherein the adjusting includes changing a temperature of the acid gas. 
     
     
         68 . The method of  claim 65  wherein the adjusting includes changing a humidity of the acid gas. 
     
     
         69 . The method of  claim 68  wherein the adjusting further includes changing a temperature of the acid gas. 
     
     
         70 - 133 . (canceled) 
     
     
         134 . The method of  claim 58  further comprising channeling the acid gas from a petrochemical chemical reaction. 
     
     
         135 . The method of  claim 59  further comprising channeling the acid gas from a petrochemical chemical reaction. 
     
     
         136 . The method of  claim 60  further comprising channeling the acid gas from a petrochemical chemical reaction. 
     
     
         137 . The method of  claim 58  further comprising channeling the acid gas from a natural gas chemical reaction. 
     
     
         138 . The method of  claim 59  further comprising channeling the acid gas from a natural gas chemical reaction. 
     
     
         139 . The method of  claim 60  further comprising channeling the acid gas from a natural gas chemical reaction. 
     
     
         140 . The method of  claim 58  further comprising channeling the acid gas from a coal chemical reaction. 
     
     
         141 . The method of  claim 59  further comprising channeling the acid gas from a coal chemical reaction. 
     
     
         142 . The method of  claim 60  further comprising channeling the acid gas from a coal chemical reaction. 
     
     
         143 . The method of  claim 58  wherein the deriving comprises adjusting an enthalpy value of acid gas. 
     
     
         144 . The method of  claim 143  wherein the adjusting includes changing a temperature of the acid gas. 
     
     
         145 . The method of  claim 143  wherein the adjusting includes changing a humidity of the acid gas. 
     
     
         146 . The method of  claim 145  wherein the adjusting further includes changing a temperature of the acid gas. 
     
     
         147 . The method of  claim 59  wherein the deriving comprises adjusting an enthalpy value of acid gas. 
     
     
         148 . The method of  claim 147  wherein the adjusting includes changing a temperature of the acid gas. 
     
     
         149 . The method of  claim 147  wherein the adjusting includes changing a humidity of the acid gas. 
     
     
         150 . The method of  claim 149  wherein the adjusting further includes changing a temperature of the acid gas.