World¡äs First! Non-phosgene TDI Green Synthesis Pilot Plant Passes Evaluation
2024-8-22
On August 18th, the world¡äs first pilot plant for non-phosgene TDI green synthesis technology, independently developed by Shaanxi Coal Chemical Industry Technology Research Institute Co.,Ltd., successfully passed the 72-hour evaluation and calibration organized by the Shaanxi Petroleum and Chemical Industry Federation.
This technology primarily encompasses four process sections: synthesis, separation, water washing, and pyrolysis. It utilizes dimethyl carbonate, a green chemical, to replace the highly toxic phosgene. This green alternative reacts with toluenediamine in the presence of a proprietary catalyst, developed in-house, to produce toluene diaminocarbamate (TDC) as an intermediate product. Following separation and water washing, TDC undergoes pyrolysis under the action of a specialized catalyst to yield toluene diisocyanate (TDI).
The company initiated the R&D project for non-phosgene TDI green synthesis in 2014. After more than three years of laboratory-scale experiments, a technical report was completed in August 2017. In August 2020, a pilot plant was constructed. Subsequently, three feeding trials were conducted in December 2020, March 2021, and August 2021, successfully establishing the process flow and obtaining the target product TDI. Following additional experiments and technical improvements, another successful feeding trial was conducted in October 2023.
The non-phosgene TDI green synthesis process offers an alternative to the traditional phosgene-based route, achieving both low-carbon green production and reduced safety risks. It aligns with China¡äs "dual carbon" goals and the industrial transformation and upgrading policies of the chemical industry. The evaluation expert panel recommends stepping up efforts to industrialize and promote the widespread application of this technology.
This technology primarily encompasses four process sections: synthesis, separation, water washing, and pyrolysis. It utilizes dimethyl carbonate, a green chemical, to replace the highly toxic phosgene. This green alternative reacts with toluenediamine in the presence of a proprietary catalyst, developed in-house, to produce toluene diaminocarbamate (TDC) as an intermediate product. Following separation and water washing, TDC undergoes pyrolysis under the action of a specialized catalyst to yield toluene diisocyanate (TDI).
The company initiated the R&D project for non-phosgene TDI green synthesis in 2014. After more than three years of laboratory-scale experiments, a technical report was completed in August 2017. In August 2020, a pilot plant was constructed. Subsequently, three feeding trials were conducted in December 2020, March 2021, and August 2021, successfully establishing the process flow and obtaining the target product TDI. Following additional experiments and technical improvements, another successful feeding trial was conducted in October 2023.
The non-phosgene TDI green synthesis process offers an alternative to the traditional phosgene-based route, achieving both low-carbon green production and reduced safety risks. It aligns with China¡äs "dual carbon" goals and the industrial transformation and upgrading policies of the chemical industry. The evaluation expert panel recommends stepping up efforts to industrialize and promote the widespread application of this technology.