Minimizing energy consumption in edible oil refining
A world-leading company in the refining of vegetable oils (palm oil, soyabean oil, rapeseed oil, sunflower oil, among others) has contacted SACOME to design and manufacture a process plant for the thermal treating of 45.000 kg/h of different types of edible oils within the refining process for one of its factories.
One of the main concerns of our client was to reduce as much as possible the energy consumption. With this in mind, our Technical Staff got involved to the maximum in the design of the tubular heat exchangers, paying special attention to the heat recovery section. We proposed our client different alternatives, advising him to get a minimum payback time to recover the initial investment.
Furthermore, our Technical Department proposed a customized design which included a special cladded insulation with the aim to minimise the heat losses to the environment, thus contributing to reduce the energy consumption.
In addition to dealing with the heat recovery, in the next sections we will go into the details of the design of heat exchangers for the processing of vegetable oils.
As stated earlier, it is not necessary to emphasize the critical importance of the energy consumption in the costs when refining oil. Using energy in the most economical way was the biggest concern for our client, hence energy recovery and reduction in the consumptions became in our main objective in the design of the tubular heat exchanger.
In this regard, our Technical Department checked different alternatives and advised our client to get a payback time as short as possible.
Moreover our engineers checked the different phases of operation, as start-up and shutdown, from the thermal and mechanical point of view.
All the above, together with the fact of the restrictive working conditions due to the high temperatures and pressures, made using the tubular heat exchangers with corrugated tubes to be the most suitable from the mechanical and thermal point of view.
Edible oils can be obtained from a wide variety of seeds, grains and nuts, being essential its refining to allow they can be used for cooking purposes.
The fact is that vegetable oils and fats contain some impurities, being some examples moisture, lecithins, insoluble solids, free fatty acids, waxes and metals as sodium, potassium, magnesium or calcium.
Colour, odour and taste are also features that must be taken into consideration to get an optimal quality for the oil.
The refining process comprises several steps such as bleaching (removal of pigments) and deodorising (removal of odor and taste), but also other stages as degumming (removing of hydratable and non-hydratable gums, i.e. lecithin), neutralising (to remove free fatty acids), and dewaxing (removal of waxes).
In all these phases, important changes of temperature (from ambient temperature up to 300 ºC) are involved.
Due to the important temperatures reached along the process (close to 300 ºC) one of the key feature in this project was to recover as much energy as possible, minimizing the heat consumption.
The heat exchanger of this project had to process different types of vegetable oil during its production cycle. Vegetable oil is an organic compound formed of triglycerides extracted from a plant.
In this regard, SACOME has hundreds of references in the processing not only of numerous types of edible oil, but also of animal fats and their derivatives, such as:
Sunflower seed oil
Fish-by-products in oil phase
This huge number of references has brought us an extensive knowledge of the process and of the different products that can be processed.
Apart from the difficulties for the thermal calculation with fluids having such low conductivity and medium viscosity, several details had to be taken into consideration by our engineers during the design stage.
As an example, some types of vegetable oils can become polymerized after the high temperatures reached during deodorisation, resulting in high fouling and even plugging of the flow paths.
It was also significant to choose properly the order in which the different oils were processed, as some kinds (to be processed the last ones) can do a self-cleaning effect in the product side.
SACOME can provide you with an extensive knowledge about the process of vegetable oils, animal fats and their derivates
Tubular Heat Exchanger Design
For this project we have supplied our I-TFM-I tubular heat exchanger, whose main features are as follows:
Corrugated inner tubes
Flanged or welded tubesheet
Self-drainability in tubeside
Removable tube bundle
Cladded and insulated frame
Process Flowrate (Kg/h)
Design Temperature (°C)
Design Pressure (bar)
Heat Recovery (kcal/h)
Floor Space (mm)