Acetylene removal process

摘要

Acetylenes are selectively removed and recovered from a C2-C12 acetylene-containing stream by contacting the stream at a temperature of 0-75 DEG C. with cuprous halide, cuprous salt of a C1-C4 monocarboxylic acids, cuprous ammonium salt of C1-C4 monocarboxylic acids or cuprous hydroxide. The contacting precipitates complexed complex acetylides of general formula wherein CuY is a cuprous salt as above and each R is a radical selected from H, C1-C11 alkyl or C1-C11 alkylene groups. The cuprous salt is dissolved in a basic solvent having solubility for the cuprous salt and a solubility of less than 1 wt. per cent for complexed complex acetylides. After contact with the solution the stream reduced in acetylene content is separated from the solvent solution. The stream may be a liquid or vapour. A proton acceptor may be present in the solvent solution or be present in the acetylene-containing stream; specified proton acceptors are ionic bases such as NaOH, KOH, NH4OH, NH3, and amines. These proton acceptors can be present in the amount of 0.1-25 wt. per cent of the solvent. The solvent may contain less than 40 wt. per cent water. The solvent may be liquid NH3, sulphoxides, amines or amides. Any amount of cuprous salt up to a supersaturated solution may be used. The mole ratio of acetylene to cuprous salts during contact may be 0.1 to 10. Liquid stream contact times can be 1-120 min. and vapour stream contact times can be 5-100 sec. The pressure during contact may be sub- or super-atmospheric, e.g. 10-120 p.s.i.a. The solvent solution and precipitated solids separated from the acetylene-containing stream, may be heated to 75-150 DEG C. to release the acetylenes and regenerate the solution. The solvent may be stripped, e.g. with N2, before and/or during regeneration. Alternatively the solid complexed complex acetylides may be removed before regeneration of the solution, then preferably stripped of physically absorbed material and heated to 75-150 DEG C. to recover the acetylenes. This latter heating may be performed in the presence of 0-1 equiv. of a proton donor, e.g. corresponding acids of the curprous salts, water and C1-C8 organic acids.ALSO:The invention comprises complexed complex acetylides of the general formula wherein CuY is a cuprous halide, cuprous salt of C1-C4 mono-carboxylic acids, cuprous ammonium salt of C1-C4 monocarboxylic acids or cuprous hydroxide, and each R is a radical selected from H, C1-C11 alkyl or C1-C11 alkylene groups. Amine-cuprous chloride complexes may be co-crystallized with the above. They are prepared in a process for selectively removing acetylenes from a C2-C12 acetylene-containing stream which comprises contacting the stream at a temperature of 0-75 DEG C. with one of the above cuprous salts. The cuprous salt is dissolved in a basic solvent having solubility for the cuprous salt and a solubility of less than 1 wt. per cent for complexed complex acetylides. After contact with the solution the stream, reduced in acetylene content, is separated from the solvent solution. The stream may be a liquid or vapour. A proton acceptor may be present in the solvent solution or be present in the acetylene-containing stream, specified proton acceptors are ionic bases such as NaOH,KOH,NH4OH,NH3, and amines. These proton acceptors can be present in the amount of 0.1-25 wt. per cent of the solvent. The solvent may contain less than 40 wt. per cent water. The solvent may be liquid NH3, sulphoxides, amines or amides. Any amount of cuprous salt up to a supersaturated solution may be used. The mole ratio of acetylene to cuprous copper during contact may be 0.1 to 10. Liquid stream contact times can be 1-120 min. and vapour stream contact times can be 5-100 sec. The pressure during contact may be sub- or super-atmospheric, e.g. 10-120 p.s.i.a. The solvent solution and precipitated solids separated from the acetylene-containing stream, may be heated to 75-150 DEG C. to release the acetylenes and regenerate the solution. The solvent may be stripped, e.g. with N2, before and/or during regeneration. Alternatively the solid complexed complex actylides may be removed before regeneration of the solution, then preferably stripped of physically absorbed material and heated to 75-150 DEG C. to recover the acetylenes. This latter heating may be performed in the presence of 0-1 equiv. of a proton donor, e.g. corresponding acids of the cuprous salts, water and C1-C8 organic acids.