20,000 Tons / Year N, N-dimethyl-1,3-propanediamine Production Technology Development

N,N-dimethyl-1,3-propanediamine(DMAPA) is an important fine organic chemical intermediate, mainly used in the manufacturing of surfactants, dyes, D213 ion exchange resin, Epoxy resin curing agent and accelerant, gasoline additives, plastics antistatic agent, lubricating oil detergent, antioxidant, emulsifier, fabric softener, fiber and leather treatment agent and bactericidal agent and so on.In the paper, acrylonitrile and dimethylamine as raw materials, firstly, β-dimethylamino propionitrile(DMAPN) was prepared in the fixed bed reactor for continuous Michael addition reaction. Then, DMAPA crude product was prepared by solvent free catalytic hydrogenation of DMAPN to batch process. Finally, the final product of high purity DMAPA was obtained by the distillation. The optimum technological conditions for continuous addition reaction are determined, they were reaction pressure from 0.50 Mpa to 0.75 MPa, reaction temperature from 28 DEG C to 36 DEG C, dimethylamine and acrylonitrile molar ratio 1.08:1.00, LHSV from 0.4 h-1 to 0.6 h-1, and acrylonitrile conversion rate up to 100%, intermediate β-dimethylamino propionitrile selectivity reached 99.8% under optimal reaction conditions. The optimum technological conditions for batch hydrogenation reaction of DMAPN and suitable catalyst are determined, the better catalyst was N211 and N311 catalyst, the better conditions were reaction pressure 4.0 MPa, reaction temperature 80 DEG C, and DMAPN conversion rate up to 100%, DMAPA selectivity reached 99% under optimal reaction conditions. The optimum conditions for DMAPA purification were determined, the better reflux ratio of light component in crude DMAPA was 10:1, and the better reflux ratio of DMAPA product isolated from the top of the tower was 3:1,and the purity of the product is more than 99.90% under optimal distillation conditionsBased on small scale technology, the continuous process and batch process combination, a high conversion rate and high selectivity DMAPA preparation technology was developed, and the formation of 20000 tons / year DMAPA production device concept design. These provide technical support for the construction of DMAPA industrial device in the future.