Crude oils are neutralized either by physical or chemical means:
In the first case the fatty acids are steam stripped, whereas in the second case they are converted into soap with caustic soda.
C.M. BERNARDINI process is fully continuous and automated with all in-line controls and continuous measurement of the oil loss in the soapstock. The plant is designed for utmost versatility, trouble-free operation and for coping with feedstock from the most different sources and with the widest range of acidity.
The plant is composed of the following main sections:
Degumming and neutralizing ;
The number of centrifuges ranges, according to the process steps required , from 2 to 3 with the first centrifuge being normally of the self-cleaning type.
This plant has been specially designed by C.M. BERNARDINI to process sunflower and corn oils. It allows to perform alkali neutralizing and winterizing in a single step only.
The process is fully automatic and continuous. Moreover , as neutralizing takes place in the cold phase, it requires only two centrifuges:
The first centrifuge for combined neutralizing and winterizing
The second centrifuge for washing
The sunflower oil processed in this unit, where no filter aid is required, passes a cold test of over 48 hours at 0 °C.
The design of C.M. BERNARDINI continuous bleaching plant is based on most advanced technology in order to reduce to a minimum the requirements of energy and bleaching earths, floor area and labor, as well as to obtain a final color fully meeting the market standards.
This is attained thanks to:
Continuous and accurate proportioning of the oil and bleaching earths and a special bleacher design.
Usually the last process step in refining is deodorizing where the oil is maintained at a high temperature and under a high vacuum for a certain period of time to crack undesired components into lower boiling products, which are then removed together with the fatty acids and other light boiling.
C.M. BERNARDINI designs and manufactures deodorizing plants of the continuous and semi-continuous type according to process and client’s requirements. The deodorizer and all parts in contact with the oil are fully made of stainless steel.
C.M. BERNARDINI deodorizers consist of a number of superimposed trays and offer the following advantages.
continuous operation and/or quick feedstock changeover with no substantial loss of operating time and with no risk of cross contamination;
very efficient mixing with oil and sparging steam thanks to special mammoth pumps;
low energy requirement;
heat recovery as high as 80% achieved by the use of special gasketsless heat exchanger;
no pollution problem as the condenser water is discharged practically fat-free, thanks to a structured packing vapor scrubber, which is provided as a standard accessory;
all operation are centralized in a control room equipped with PC/PLC .
C.M. BERNARDINI deodorizers process fats and oils on a continuous or semi-continuous basis under programmed and optimum conditions of time and temperature. They are delivered complete with a heating station.
The characteristics of certain oils and fats, such as palm, palm kernel and coconuts oils, tallow, etc., make it possible to deacidify and deodorize them in a single step. In some cases, this is possible, after a very efficient degumming, also for sunflower, soybean, rapeseed, corn oils, etc.
This process has the following distinct advantages vs. alkali refining:
Combined neutralizing and deodorizing;
Direct production of distilled fatty acids instead of soapstock;
Higher yield as no neutral oil is lost in the soapstoack;
Fully continuous and automatic operation with minimum supervision by a single operator who is also in charge of other sections.
For oils the plant includes a structured packing section built in the deodorizer tower.
Fats and oils are marketed with a cold stability temperature determined by a cold test.
To comply with such standard, certain vegetable oils require a winterizing process consisting in precipitating as crystals, under programmed conditions of temperature and time, the saturated glycerides or waxes, which cause them to become cloudy.
The processes normally used are:
As an alternative to winterizing combined with neutralizing, CM BERNARDINI has developed a winterizing system that allows to process almost any type of oil according to the most suitable cooling curve and under the most favorable conditions of temperature , time and agitation.
The latter factors are of primary importance for the formation and nature of the crystals
According to the types of filters installed , filter aid can be used or avoided.
Fully automatic filters are provided for the removal of the solid phase from the crystallized mass.
The main features of C.M. BERNARDINI dry system are:
Possibility of carrying out single or double fractionation without making any modification to the plant and to obtain different kinds of oleine at a different cloud point;
Possibility of obtaining qualities of stearine with a different iodine value and melting point ;
Use of special crystallizers having very high specific surfaces;
Continuous automatic control of the temperature over the oil crystallization curve, controlling at the same time also the cooling water temperature.
This allows to maintain always the same reduced temperature difference between oil and cooling water in order to get the proper crystals growth.
C.M. BERNARDINI dry fractionation plant can be supplied with a membrane or vacuum rotary filter.
A PLC-based control system is provided for the overall process supervision