Published March 2019
Hydrochloric acid (HCl) is available commercially in anhydrous gas form or as an aqueous solution. Anhydrous HCl is highly hydroscopic; it produces white hydrochloric acid fumes when it comes into contact with moist air. Anhydrous HCl gas dissolves in water and produces hydrochloric acid, which is also known as muriatic acid. Commercially, hydrochloric (muriatic) acid is available in different concentration solutions. It is a highly corrosive liquid that must be stored and handled safely. Hydrochloric acid is one of the most important inorganic basic chemicals and is widely used in the chemical industry as a reagent in the manufacturing of other chemicals. The largest end uses for hydrochloric acid are steel pickling, oil well acidizing, food manufacturing, calcium chloride producing, and ore processing.
Academicians, industry researchers, and hydrochloric acid production process technology licensors have published several research papers, scientific reviews, technical reports, and patents. S&P Global’s Process Economics Program (PEP) previous covered HCL in PEP Report 134, Hydrochloric Acid (November 1979), which presented a technoeconomic analysis of HCl from different technologies. The economic evaluation of anhydrous HCl production presented in this review is PEP’s independent interpretation based on companies’ patent literature and other open source information. It may not reflect, in whole or in part, the actual plant configuration.
This review covers three anhydrous hydrochloric acid production processes:
- Anhydrous HCl production from dehydration by concentrated sulfuric acid process
- Anhydrous HCl production by hydrochloric acid boiling process
- Anhydrous HCl production by electrolysis of rock salt via membrane cells process
This review presents a technoeconomic assessment of the abovementioned anhydrous HCl production processes, along with an overall picture of the carbon and water footprints of these processes. The review also includes an interactive costing module (iPEP Navigator), which provides a snapshot of the economics of all the anhydrous hydrogen chloride processes. The module also allows the user to select the process, units, and region of interest according to the user’s costing needs.