If you think that the use of lye is circumscribed only to soap making and domestic cleaning, you maybe wrong. Lye or caustic soda has an array of industrial applications too. An essential ingredient in multifarious industrial processes, lye is normally produced by the chlor-alkali process which involves use of brine solution. When manufactured through this process, caustic soda or lye is produced along with chlorine and hydrogen. Some of the impurities that are found in such industrial lye are: sodium chloride, sodium carbonate and sodium sulfate. All these impurities are removed and only 100% lye is present in the caustic soda supplied by your soap making or chemical supplier.
Let’s take a look at the various industrial applications of lye:
1. Paper industry: Lye finds the greatest usage in the pulp and paper industry worldwide. It is used in the de-inking of waste paper and water treatment during pulp and paper manufacturing process. It is also a raw material in the pulp bleaching process. Many manufacturers produce and supply lye only as an essential ingredient for this industry.
2. Textile industry: Lye is used to process cotton and other synthetic fibers like nylon and polyester. Though otherwise caustic on fabrics and surfaces, as a manufacturing ingredient, it finds importance in textile industry.
3. Bleach production: Lye’s popular usage is that of a domestic bleach and cleaner. It is widely used in the bleaching industry, which has consumer applications like mold and mildew control at home or microbial or other infection control in swimming pools, hot tubs, tanks etc.
4. Petroleum production: Lye is used in the processing of petroleum and natural gas. As caustic soda, it removes unwanted odors from petroleum products. Lye is effective in eliminating objectionable smells caused from materials like hydrogen sulfide and mercaptans.
5. Production of aluminum: Lye is used in dissolving bauxite ore, an essential raw material for aluminum production.
6. Feedstock in chemical processes: Lye is used as a basic feedstock for a wide range of products. This includes solvents, plastics, fabrics, adhesives, herbicides, dyes, inks, pharmaceuticals, coatings etc.
7. Soap making: The most common use of lye is in soap making. Everyone from homemade soap makers to large scale soap manufacturers make soaps using lye. Lye soap is still a favorite with many. Laundry soaps made from lye are extremely useful in removing stains, bleaching white clothes etc.
8. Food processing: The food processing industry finds a good and reliable preservative in lye. It is used in the curing of many food stuff, including processing of lutefisk, green olives, hominy, lye rolls, century eggs, pretzels, Chinese dumplings and noodles.
9. Small applications of lye: Caustic soda is used in water treatment, drain cleaners and openers, oven cleaning, household and domestic cleaning products, cleaning beverage bottles etc.