Title : Development of specialty amines derived from acrylonitrile: A case study of N,N-dimethyl-1,3-propanediamine
Abstract:
Acrylonitrile serves as a key intermediate in the petrochemical industry and provides an essential feedstock for numerous downstream products including synthetic fibers, plastics, rubbers, and fine chemicals. Rapid expansion of global acrylonitrile capacity in recent years has created a supply surplus that has reduced market prices and compressed industrial profit margins. Development of high-value downstream products therefore represents an important pathway for improving the economic competitiveness of the acrylonitrile industry. Specialty amines derived from acrylonitrile have attracted increasing attention because they exhibit broad applications in personal care products, pharmaceuticals, surfactants, and functional materials.
This study investigates the catalytic synthesis of N,N-dimethyl-1,3-propanediamine, an important intermediate widely used in the production of surfactants and cosmetic ingredients. Industrial production technologies for this compound remain dominated by foreign continuous processes, while domestic production primarily relies on batch operations with limited efficiency and scalability. Development of efficient catalytic systems and scalable reaction processes therefore represents a critical objective for improving domestic production capacity.
A supported Ni-based catalytic system was designed for the amination and hydrogenation reactions involved in the synthesis route. Systematic screening of active metals and catalyst supports was conducted to improve catalytic activity, selectivity, and stability. Commercial Al2O3 exhibited favorable surface properties and strong metal dispersion ability and therefore served as an effective catalyst support. Catalyst deactivation behavior was investigated through XRD, XPS, TEM, and thermogravimetric analysis. The results demonstrate that catalyst deactivation primarily originates from metal oxidation, carbon deposition, and particle sintering during the reaction process. Catalyst modification strategies were subsequently developed in order to enhance stability. Introduction of Cu effectively suppressed metal sintering, while incorporation of CeO2 reduced carbon deposition and allowed a lower Ni loading without sacrificing catalytic performance.
The optimized catalytic system achieved complete conversion of acrylonitrile and produced the intermediate N,N-dimethylaminopropionitrile with a yield of 99.7 percent. Subsequent hydrogenation afforded N,N-dimethyl-1,3-propanediamine with yields exceeding 90 percent under optimized reaction conditions. The developed catalytic process was successfully scaled from laboratory reactors to a 20 L pilot reactor. Comprehensive safety evaluation including risk assessment and HAZOP analysis confirmed the operational safety and technical feasibility of the process.
This work further explores catalytic synthesis routes for additional acrylonitrile-derived specialty amines including propionitrile and N,N-bis (3-aminopropyl) methylamine. The results demonstrate that catalytic amination and hydrogenation strategies provide an efficient pathway for the scalable synthesis of high-value specialty amines from acrylonitrile. The study therefore offers a practical catalytic and process development framework for upgrading acrylonitrile downstream products and supports the industrial production of high-value functional amines.
