What are the main production routes for hydrochloric acid and how do they affect supply?

Industrial hydrochloric acid is predominantly a byproduct of chlor-alkali electrolysis, where saturated brine is electrolyzed to produce chlorine, hydrogen, and caustic soda. The hydrogen and chlorine are then burned to form hydrogen chloride gas, which is absorbed in water to yield hydrochloric acid. This means supply is tightly coupled to caustic soda and chlorine demand rather than driven by standalone acid plants. A second route involves Mannheim furnaces reacting potassium chloride with sulfuric acid, generating hydrogen chloride as a coproduct alongside potassium sulfate. A third, increasingly important source is organic synthesis, where HCl is recovered as a byproduct from processes like PVC or chlorinated solvent production. These byproduct streams often feed the merchant market, making price dynamics more dependent on upstream operating rates than on acid-specific demand.