Uses of KABE

Use in the Petroleum Industry

Bleaching earth or clay is a decolorizing and clarification agent that is much used in the oil industries for the bleaching of vegetable, animal and mineral oils, fats and waxes.

There are two types of bleaching earths - the natural or fuller's earth and the highly active, chemically-processed earth.

Bleaching earth, which is obtained from selected raw material and has naturally a certain bleaching power, requires only simple treatment in its preparation, such as drying and milling it to the desired fineness.

In the petroleum industry, activated bleaching earth is used in the refining, decolourization, deodorization of petroleum based products and petroleum by-products. Activated bleaching earth is produced by a process involving treatment with sulphuric acid, hydrochloric acid or phosphoric acid. Such chemically treated material has an efficacy considerably greater than that of the natural bleaching earths.

For this reason less bleaching agent is required for a desired degree of decolorizing and less oil is lost in the process, since a certain percentage of oil is retained in the earth after filtering. In order to operate most economically and reduce this oil loss to a minimum, one uses advantageously the most highly activated earth possible.

Drilling mud, using bleaching earth is prepared mainly for deep drilling, like oil-well drilling. Bleaching earth imparts two properties:

• It gives the fluid a viscosity several times that of water.
• It seals the wall of the holes, thus preventing water loss.

The quantity of bleaching earth used is variable depending upon the depth of the hole to be drilled. Generally one ton of bleaching earth is used to prepare about 100 barrels of mud.

Decolourizing bleaching earths are those which carry calcium and/or magnesium as an exchangeable ion. They are used in the decolourization of petroleum oil. These are decolourized in two ways:

• By the percolation method.
• By the contact method.

Activated bleaching earth is used in the granular form. Oil is passed through a bed of granules, which as a result is decolourized, deodorized and refined. These granules once used, cannot be used again as they now contain oil.

Statistics show that use of bleaching earth is heavily dependent on the oil and petroleum industry. Increase in natural gas demand will mean continuing growth in exploration and a higher demand for the product.

Use in the Edible Oil Industry

Activated bleaching earth is used for the stabilizing, neutralising, clarifying and decolourising mineral oils, fats and waxes. It is also used for bleaching and decolourising edible oils such as coconut oil, palm oil, cotton seed oil, corn oil, sunflower seed oil, olive oil, soyabean oil, castor oil, mustard oil, groundnut oil, sesame oil and rice bran oil. It helps in removing colour bodies and impurities from oils.

Bleaching earth is a suitable agent for bleaching and decolourising degummed and alkali refined oil. The property of adsorption of bleaching earth is used in this process. In bleaching, it is used alone with activated carbon to remove colour, gums, resins and other impurities present in the oil.

There are two methods of using bleaching earth in the processes mentioned.

• Percolation Method: The material to be processed is filtered through a column of granular bleaching earth which has been heat activated, usually between 300°C to 600°C. The rate of percolation, temperature of operation and optimum temperature of activation of bleaching earth are variable, which are determined experimentally for a specific application.
• Contact Method: The material to be treated is mixed with bleaching earth and the slurry is stirred for period of five to thirty minutes at elevated temperature under vacuum. The treated product is recovered by filtering through a plate and a frame or a continuous type of filter for optimum result. The amount of bleaching earth used, the temperature and the time of treatment are determined experimentally.

Other Industrial Uses of Bleaching Earth

The other areas where activated bleaching earth is used are:

• Refining, decolourizing and bitumen extraction in sulphur production.
• Powder fire extinguishing agents and binding agents for oil on water.
• Refining, decolourizing and purifying of mineral oils, fats, waxes, paraffin. Bleaching earth is also used as a catalyst for oil cracking and in grease thickening.
• Refining of wine, beer stabilization, purifying of saccharine juice and syrup.
• In the chemical industry as catalysts carriers, dehydrating agents, water and waste-water purification adsorbents.
• As a colour developer in carbonless copying paper and stabilising the hydrogen peroxide used to bleach paper.
• For generating organic fluids used for dry cleaning.
• Used in polishes and dressings, additives for washing and cleaning agents and for soap production.
• As starting material for healing earths and bases for creams and cosmetics.
  As a binding agent for ore pelletising.
• In supporting suspensions for cut-off diaphragm wall constructions and shield tunnelling/subsoil sealing (for example - dumps), anti-friction agents for pipe jacking and shaft sinking, additive for soil concrete and mortar.