Crude glycerine is the raw material for producing pure glycerine. It is a less pure form of glycerine. It is produced during biodiesel production. It is also known by the name glycerol. For every 100 pounds of biodiesel products created, there is about 10 pounds of crude glycerol produced as by-product.

Glycerine is a hygroscopic trihydroxy alcohol that occurs as combined glycerides and is formed by alcoholic fermentation of sugars, which is a by-product from soap or fatty acids manufacturing. Glycerol is a colourless, odourless, viscous liquid that’s sweet-tasting and non-toxic. While pure glycerine is colorless and has a sweet taste, less pure glycerol stands out due to its usually brown color. It can also vary in color. In crude glycerine, the sweet taste that pure glycerine has is masked by the higher salt content. It is widely used in pharmaceutical industry and as sweetener in the food industry.

Glycerine can be found in higher plants and in animals. In humans, glycerine is accumulated in the form of lipid in muscle tissues. There are 2 types of glycerine – natural and synthetic. Natural glycerine is derived from oils and fats like coconuts, peanuts, palm oils etc. Synthetic glycerine is usually derived from petroleum.


  • Manufacturing :
    Castner-Kellener process - Here,caustic soda is prepared by the electrolysis of aqueous NaCl. It consist mercury cathode cell which is a rectangular vessel divided into three compartments by a non-porous slate partition which do not touch the bottom of the cell. A layer of mercury divides each compartments at the bottom of the cell. One end of the cell is pivoted and the rest of the part rests on an in centric wheel, which gives the rocking motion to the cell so mercury can circulate from one compartment to other.

    Castner-Kellener cell - It is a rectangular cell made up of steel. The inner walls of the tank is lined wih ‘ebonite’. Anode is titanium and mercury acts as cathode.

    Ionization of NaCl - When the solution is subjected to electric discharge the NaCl disassociates into Na+&Cl- ions, now the positive and negative charges migrates towards its respective electrodes. The sodium deposited at mercury forms sodium amalgam and the chlorine produces at the anode is removed from the top of the cell.
    Reaction at cathod - 2Na++2e-→2Na  |  Na+Hg→Na/Hg           Reaction at anode - 2Cl-Cl2+2e- 

  • Formation of NaOH :

    Amalgam now passed to the other chamber known as ‘denuder’, where it is treated with water to produce NaOH, it is in liquid state. Now it produced by multi stage evaporation process and transformed into solid stated as micro spherical particles called prills.

It is used in many applications, for the production of pulp, aluminum, sugar, soaps and detergents. It is used as catalyst in production of biodiesel. It is used as a cleaning and disinfectant agent.

  • Aluminum Industry : Caustic prill is used to dissolve bauxite ore, the raw material for its production.
  • Soap and detergent: It is used in saponification, conversion of fat, vegetable oil into soap. It’s also used in production of anionic surfactants, a crucial component in most detergents and cleaning products.
  • Textile Industry: Used to process cotton and dye synthetic fibers and such as nylon and polyester.
  • Paper industry: Here it involves in pulping and bleaching processes, the de-inking of waste paper and water treatment.
  • Other applications: it is used to make bleach, which has industrial and consumer applications, and also used in petroleum processing, pharmaceutical, pH control, paint stripper, Ion exchange resin regeneration.
  • Used as internal combustion fuel in electric cars.
  • Used as antifreeze in chemical industries.
Property Units Value
Appearance   White pearls
NaOH % 99.00 (min)
Na2SO4 % 0.038 (max)
Na2CO3 % 0.94 (max)
NaCl % 0.022 (max)
Fe ppm 5 (max)
Ni ppm 3 (max)