Catalytic Processes for Environmentally Friendly Methylene Diphenyl Diisocyanate Production

Isocyanates are industrially produced using strong mineral acids (e.g. HCl), in the condensation of aniline to produce methylenedianiline (MDA), and phosgene, in the conversion of MDA to the corresponding isocyanates. Huge quantities of sodium chloride, contaminated with organic compounds, are produced during process, and their disposal is a relevant issue.