Patent GB-467581-A (GB)
Title: Improvements relating to the purification of gases and liquids from carbon disulphide
IPC: C10K1/14
Filed: 1935-12-18
Abstract: Carbon disulphide is recovered from liquids or gases by treating them with a solution of a secondary amine salt of a disubstituted dithiocarbamic acid and a metallic oxide or hydroxide to form a metallic dithiocarbamate which is then removed from contact with the source of carbon disulphide and is decomposed to regenerate carbon disulphide and the secondary amine salt, the salt so regenerated being used again, if necessary with the addition of further metallic oxide or hydroxide, to absorb a further quantity of carbon disulphide.  Suitable combinations of starting materials are the piperidine salt of pentamethylene-dithiocarbamic acid in conjunction with magnesium oxide if liquids are to be treated, or with calcium oxide if gases are to be treated.  Reference is also made to the diethanolamine, diethylamine and morpholine salts of the substituted dithiocarbamic acids derived respectively from diethanolamine, diethylamine and morpholine.  The use of cadmium lead and zinc oxides is also referred to.  Regeneration may be effected by heating or in cases where simple heating does not suffice, by treatment with sulphuric acid or carbon dioxide, the presence of some water being necessary in the case of heating or treatment with carbon dioxide. The process is applicable to the purification of hydrocarbon liquids such as crude benzol, an aqueous solution of the secondary amine salt being employed.  The Provisional Specification describes also the employment of the corresponding primary amine or ammonium salts and refers to the purification of crude naphtha.ALSO:Carbon disulphide is recovered from liquids or gases by treating them with a solution of a secondary amine salt of a disubstituted dithiocarbamic acid and a metallic oxide or hydroxide to form a metallic dithiocarbamate which is then removed from contact with the source of carbon disulphide and is decomposed to regenerate carbon disulphide and the secondary amine salt, the salt so regenerated being used again, if necessary with the addition of further metallic oxide or hydroxide, to absorb a further quantity of carbon disulphide.  Suitable combination of starting materials are the piperidine salt of pentamethylene-dithiocarbamic acid in conjunction with magnesium oxide if liquids are to be treated, or with calcium oxide if gases are to be treated.  Reference is also made to the diethanolamine, diethylamine and morpholine salts of the substituted dithiocarbamic acids derived respectively from diethanolamine, diethylamine and morpholine.  The use of cadmium, lead and zinc oxides is also referred to.  Regeneration may be effected by heating or in cases where simple heating does not suffice, by treatment with sulphuric acid or carbon dioxide, the presence of some water being necessary in the case of heating or treatment with carbon dioxide.  The process is applicable to the purification of hydrocarbon liquids such as crude benzol, an aqueous solution of the secondary amine salt being employed.  The Provisional Specification describes also the employment of the corresponding primary amine or ammonium salts and refers to the purification of crude naphtha.