SINGAPORE: Hydrochloric acid (HCl) is a clear, colorless, highly pungent solution of hydrogen chloride in water. It is an extremely important product of the chemical industry and used in many industrial processes. Here are some of the important applications and uses of hydrochloric acid.
Steel Pickling: This is a process whereby rust and scale is removed from steel sheet or coil with the use of a dilute solution of hydrochloric acid. The metal can then be processed. Hydrochloric acid is used in pickling operations for carbon, alloy and stainless steels. Pickling is required for steel products that undergo further processing such as wire production, coating of sheet and strip, and tin mill products. Hydrochloric acid is used primarily for continuous pickling operations in which hot-rolled strip steel is passed through a countercurrent flow of acid solution.
Used in manufacture of organic compounds: HCl is used to manufacture organic compounds such as vinyl chloride and dichloroethane which are used to produce polyvinyl chloride (PVC).
HCl as cleaning agent: One of the strongest commercially available cleaners today is hydrochloric acid. Hydrochloric acid is extremely powerful and is recommended as a cleaner. Industrial strength hydrochloric acid, is commonly used on masonry; however, the acid can be used to clean any product that can withstand its effects.
Used to neutralise water in swimming pools: HCl is used to neutralize water in making it safe for bathers. Most often the pH level is high; the best way to lower pH is by slowly pouring hydrochloric acid directly into the deep end of the pool while the pool pump is on and the water is circulating.
Used to regulate pH level: HCl is used to regulate the pH level in a wide range of manufacturing and treatment processes including the production of drinking water, pharmaceuticals, beverages and foods. It is used in the processing of additives for the food industry including fructose, citric acid and hydrolyzed vegetable protein.
Cleans up accumulated algea, zebra mussels on pontoon boats: Aluminum pontoons on pontoon boats accumulate algea, zebra mussels, etc and become badly fouled in one or two seasons. Low odour hydrochloric acid cleans it up very well. Apply with pump up garden sprayer (all plastic) and wash off after 5 - 10 minutes with water or pressure washer. Very expensive cleaners are sold for this same purpose and do not work any better.
To regenerate ion exchangers: High-quality hydrochloric acid is used in the regeneration of ion exchange resins. HCl is very efficient and does not cause precipitations in the resin bed. Cation exchange is widely used to remove ions such as Na+ and Ca2+ from aqueous solutions, producing demineralized water. The acid is used to rinse the cations from the resins. Na+ is replaced with H+ and Ca2+ with 2H+.
Used in activating oil wells: HCl is used in a process known as oil-well acidization. This process involves injecting the acid into the cavities of oil wells to dissolve away sections of rock, leaving an open column behind. Ultimately, the method serves to accelerate oil production from the well.
Production of inorganic compounds: Numerous products can be produced with hydrochloric acid in normal acid-base reactions, resulting in inorganic compounds. These include water treatment chemicals such as iron(III) chloride and polyaluminium chloride (PAC).
Fe2O3 + 6 HCl → 2 FeCl3 + 3 H2O
(ferric oxide) (ferric chloride)
Both iron(III) chloride and PAC are used as flocculation and coagulation agents in wastewater treatment, drinking water production, and paper production.
pH control and neutralization: Hydrochloric acid can be used to regulate the basicity (pH) of solutions.
OH− + HCl → H2O + Cl−
In industry demanding purity (food, pharmaceutical, drinking water), high-quality hydrochloric acid is used to control the pH of process water streams. In less-demanding industry, technical quality hydrochloric acid suffices for neutralizing waste streams and swimming pool treatment.
No comments:
Post a Comment