System for the chemical decontamination of corrosive gases

Abstract

The use of a composition including at least one acido-basic neutralising agent for decontaminating an atmosphere contaminated by a corrosive gas, the acido-basic neutralising agent having at least 2 pKa's and being characterised by: pKa 1≤pKa 2, pKa 1>2, pKa 2<12, 4<½ (pKa 1+pKa 2)<10 pKa 1, representing the smallest of the basic pKa's and pKa 2 representing the largest of the acidic pKa's. Also, a method for decontaminating an atmosphere contaminated by a corrosive gas comprising the spraying of the neutralising agent, and to a decontamination device.

1 . A composition comprising at least one acido-basic neutralising agent for decontaminating an atmosphere contaminated by a corrosive gas, said at least one acido-basic neutralising agent being an amphoteric agent selected from the group consisting of: an amino acid or a salt of an amino acid, a citric acid salt, a phosphoric acid salt, a pyrophosphoric acid salt, an ethylenediaminetetraacetic acid (EDTA) salt, complexed or free, and a carbonate, and said at least one acido-basic having at least 2 pKa's, wherein:
   pKa 1≤pKa 2,
     pKa 1>2,     pKa 2<12−4<½, and
     (pKa 1+pKa 2)<10,   pKa 1 representing the smallest of the basic pKa's and pKa 2 represents the largest of the acidic pKa's.   
     
     
         2 . The composition according to  claim 1 , wherein said composition is in solution form or in solid form. 
     
     
         3 . The composition according to  claim 2 , wherein said composition in solution form or in solid form is formulated as an aerosol. 
     
     
         4 . The composition according to  claim 2 , wherein said composition in solution form is formulated as a foam. 
     
     
         5 . The composition according to  claim 1 , wherein said composition is sprayed directly into the atmosphere contaminated by corrosive gases. 
     
     
         6 . The composition according to  claim 1 , wherein said at least one acido-basic neutralising agent is sodium glutamate. 
     
     
         7 . The composition according to  claim 1 , wherein said at least one acido-basic neutralising agent is L-alanine. 
     
     
         8 . The composition according to  claim 1 , wherein said at least one acido-basic neutralising agent is EDTA disodium. 
     
     
         9 . The composition according to  claim 1 , wherein said at least one acido-basic neutralising agent is a hydrogencarbonate. 
     
     
         10 . The composition according to  claim 9 , wherein said at least one acido-basic neutralising agent is a sodium hydrogencarbonate. 
     
     
         11 . A method for decontaminating an atmosphere contaminated by a corrosive gas comprising the following steps:
 1) spraying, directly into the contaminated atmosphere, a composition comprising at least one acido-basic neutralising agent for decontaminating an atmosphere contaminated by a corrosive gas, said at least one acido-basic neutralising agent being an amphoteric agent selected from the group consisting of: an amino acid or a salt of an amino acid, a citric acid salt, a phosphoric acid salt, a pyrophosphoric acid salt, an ethylenediaminetetraacetic acid (EDTA) salt, complexed or free, and a carbonate, and said at least one acido-basic having at least 2 pKa's and wherein:
   pKa 1≤pKa 2,
 
   pKa 1>2, 
   pKa 2<12−4<½, and
 
   (pKa 1+pKa 2)<10, 
   pKa 1 representing the smallest of the basic pKa's and pKa 2 represents the largest of the acidic pKa's; then   2) checking the decontamination;   3) optionally repeating steps 1 and 2 until there is total decontamination;   4) recovering the solid or liquid residues; and   5) optionally rinsing the decontaminated zone to eliminate the residues of the composition.   
     
     
         12 . A device for decontaminating an atmosphere contaminated by a corrosive gas, comprising:
 at least one means able to spray a composition comprising at least one acido-basic neutralising agent for decontaminating an atmosphere contaminated by a corrosive gas, said at least one acido-basic neutralising agent being an amphoteric agent selected from the group consisting of: an amino acid or a salt of an amino acid, a citric acid salt, a phosphoric acid salt, a pyrophosphoric acid salt, an ethylenediaminetetraacetic acid (EDTA) salt, complexed or free, and a carbonate, and said at least one acido-basic having at least 2 pKa's and wherein:
   pKa 1≤pKa 2,
 
   pKa 1>2, 
   pKa 2<12−4<½, and
 
   (pKa 1+pKa 2)<10, 
   pKa 1 representing the smallest of the basic pKa's and pKa 2 represents the largest of the acidic pKa's; and   at least one reservoir intended to receive said composition.   
     
     
         13 . The device according to  claim 12 , wherein said at least one reservoir is connected to at least one circuit comprising a fluid, said at least one circuit being a circuit belonging to a fire extinguishing plant.