Process for the preparation of a catalyst useful for liquid-liquid sweetening lpg and light petroleum distillates

Abstract

The present invention relates to a process for the preparation of metal phthalocyanine sulphonamide [MPc(SO NHR) ] catalyst useful for sweetening of LPG and light petroleum distillates which comprises reacting a metal phthalocyanine with chlorosulphonic acid at 90-150° C. for 1-5 hrs. cooling the reaction mixture adding 1-7 parts of a chloride reagent heating the said mixture at 60-80° C. from 0.5-3 hrs. to obtain the metal phthalocyanine sulphonyl chloride, isolating it by adding the reaction mixture in ice cold water, reacting the isolated metal phthalocyanine sulphonyl chloride with an amine of general formula H NR where R is selected from hydrogen, aryl, alkyl and cycloalkyl in an aqueous or non-aqueous medium or a mixture thereof at a temperature in the range −4 to 15° C. and at a pH ranging between 7-9 in the presence of an acid binding agent to obtain the described metal phthalocyanine sulphonamide catalyst wherein the chloride reagent used is selected from the group consisting of thionyl chloride, phosphorus trichloride and phosphorus pentachloride, the binding agent used is selected from the group consisting of sodium bicarbonate, sodium carbonate, sodium hydroxide and tertiary organic bases selected from pyridine triethyl amine and piperidine and the catalyst metal phthalocyanine sulphonamide is selected from the group consisting of cobalt, manganese, nickel, iron vanadium phthalocyanine sulfonamide most preferably cobalt phthalocyanine sulphonamide.