Process Technology Route

The production of TDI by phosgenation method is currently the unique mature industrial process in the world.
The technology consists of five main production processes: the reaction of carbon monoxide and chlorine to produce phosgene; the reaction of toluene with nitric acid to produce dinitrotoluene (DNT); the reaction of DNT with hydrogen to produce methyltoluene diamine (MTD); the reaction of dried MTD with phosgene to produce toluene diisocyanate (TDI); and the purification and recovery of the TDI product.

Technological characteristics

The nitrification reaction adopts the pump-type continuous nitrification method, which has a high conversion rate, less by-products and is safer.
The hydrogenation reaction is catalyzed by nickel catalyst. The reaction is homogeneous, the catalyst separation process is simple, and the catalyst loss is low.
TDI synthesis adopts two-step reaction of liquid phosgene reaction and jet tower type. Uniform mixing, rapid reaction, high conversion rate, less by-products, high product purity, the solvent is light solvent, and the process is relatively simplified.