| 摘要 |
A hydrocyanation reaction is used to react 1,3-butadiene with hydrogen cyanide in the presence of a catalyst to produce pentenenitriles, as well as reaction byproducts, such as methylglutaronitrile (MGN). The effluent from the hydrocyanation reaction is distilled in a particular manner to produce a pentenenitrile-enriched stream, a catalyst-enriched stream and a stream enriched in methylglutaronitrile (MGN). At least a portion of the catalyst enriched stream may be recycled to the hydrocyanation reaction. 3-pentenenitrile may be recovered and, optionally, further reacted with HCN to make adiponitrile (ADN). |
| 主权项 |
1. A process for making adiponitrile, said process comprising the steps of:
(i) reacting in a reaction zone a mixture comprising 1,3-butadiene (BD) and hydrogen cyanide (HCN) in the presence of a catalyst comprising zero-valent Ni and a phosphorus-containing ligand, wherein said phosphorus-containing ligand is selected from the group consisting of a monodentate or bidentate phosphite ligand, a monodentate or bidentate phosphine ligand, a monodentate or bidentate phosphonite ligand, a monodentate or bidentate phosphinite ligand, and a mixture of these ligands, to produce a reaction product comprising 3-pentenenitrile (3PN), 2-methyl-3-butenenitrile (2M3BN), adiponitrile (ADN), and methylglutaronitrile (MGN); (ii) distilling the effluent from the reaction zone of step (i) to remove 1-3-butadiene and to obtain a 1,3-butadiene-depleted stream; (iii) distilling the 1,3-butadiene-depleted stream from step (ii) to obtain streams comprising a pentenenitrile-enriched stream and a catalyst-enriched stream; and (iv) recycling at least a portion of the catalyst-enriched stream of step (iii) to the reaction zone of step (i),
wherein catalyst flows through the reaction zone along with reactants and products,wherein the 1,3-butadiene-depleted stream from step (ii) is introduced into a distillation column comprising a feed inlet, an upper draw outlet, a side draw outlet, a bottom draw outlet and a rectifying section,wherein the rectifying section is provided between the feed inlet and the upper draw outlet,wherein the rectifying section comprises at least two stages of separation,wherein the pentenenitrile-enriched stream of step (iii) is withdrawn from the upper draw outlet,wherein the catalyst-enriched stream of step (iii) is withdrawn from the bottom draw outlet,wherein the rectifying section further comprises a liquid collection apparatus,wherein the liquid collection apparatus is located above the feed inlet,wherein liquid is collected in the liquid collection apparatus and passed through the side draw outlet to form a side draw stream, andwherein the side draw stream comprises methylglutaronitrile (MGN). |
