THE MANNHEIM PROCESS
Traditionally, SOP has been produced by the Mannheim process, in which KCl is reacted with sulfuric acid to yield K2SO4. Although this method does work, it produces the desired compound as a byproduct; the primary product resulting from the process is HCl.
This process consists of first carrying out an exothermic reaction between potassium chloride (KCl) and sulfuric acid (H2SO4), and then an endothermic reaction between potassium chloride (KCl) and potassium bisulfate (KHSO4) to produce HCl and K2SO4.
The resulting K2SO4 is cooled in a rotary cooler and may then be further finished into the desired product form.
