Hydrogenation is an oils and fats modification process.It is mainly used on
vegetable oils like soya, rape, cotton or sunflower to increase their
oxidative stability and to improve their melting properties by reducing
their degree of unsaturation. As a result, these oils or fats reach a
consistency that is ideal for use as margarine or shortening components
Hydrogenation is a reaction involving the use of a catalyst, most generally
nickel, and is also an exothermic reaction.
Careful and precise hydrogenation requires that the constituents
oil, gaseous hydrogen and solid catalyst should be mixed perfectly.
This is done in a closed vessel, by agitation of the catalyst fatty
material suspension in contact with hydrogen.
The purpose of agitation is to promote hydrogen absorption and to maintain
a permanent flow of fatty material through the pores of the catalyst. To do
this, we use the Hydrogenator, in which hydrogen is forced into the oil and
remains in it until the gas is fully consumed. The hydrogenator is batch
type. It is equipped with several features to control and master reaction
pressure, reaction temperature and the quantity and flow of hydrogen
injected, all of which are essential to guarantee selective hydrogenation.
The feedstock used for hydrogenation is usually caustic refined and
bleached oil. With the improvement of the degumming processes, there is a
tendency to hydrogenate degummed oils. After hardening, those oils are
bleached and physically refined.
Main Advantages of this process are:
Improved gas dispersion;
Low specific energy consumption;
Fully automated plant and reliable controls;
No venting required as hydrogen is entirely consumed at the end of
The process of fractionation consists of the separation of the liquid part
(olein) from the solid part (stearin). In principle the process is very
Keeping the fat at a controlled temperature to allow crystallization.
Separate the formed crystals
Veendeep has adopted the dry fractionation process operating batch
wise, as opposed to centrifugal separation with the aid of detergents or
solvent fractionation. With this process oil is kept at a controlled
temperature in large tanks with slow stirrers. Crystals form and build into
aggregates of several millimetres in diameter. The slurry is pumped through
a membrane-filter press for separation of the olein and stearin fraction.
The stearin cake obtained from the membrane filter press is melted in the
stearin-melting tank below the press, which also acts as a stearin
intermediate tank, prior to storage or packaging.