Raschig process

The Raschig process is a chemical process for the production of hydroxylamine, developed by German chemist Friedrich Raschig. The main step in this process, patented by Raschig in 1887, is the reduction of nitrite with bisulfite towards hydroxylamine disulfonate, which is hydrolysed to hydroxylammonium sulfate. Most of the hydroxylamine produced is used in the manufacture of caprolactam, the precursor to the polymer Nylon 6.

The commercially used Raschig process consists of the following steps: