Hydrogenation is an oils and fats modification process.It is mainly used on vegetable oils like soya, 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 reaction