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De Smet provides advanced solutions for the industry
| Refining |
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De Smet supplied over 200 wet and 250 dry degumming units. Degumming  Degumming is the first operation in refining. The Impac® Degumming process consists of a mere hydration of the crude oil. Certain impurities like phospholipids, gums and proteins are soluble in oil in their anhydrous form, but insoluble once they are hydrated. This is how the hydratable phospholipids are removed from the oil. Part of the constituents however remain in the oil, and an acid treatment is needed to remove them.Water degumming is more generally carried out in the extraction plant rather than in the refinery, lest foots should conglomerate in the crude oil intermediate tanks. The aqueous phase obtained after degumming separation is recirculated into the meal stream of the toaster. Should lecithin be of significant commercial value, it can be dried separately. De Smet has supplied over 145 neutralising units. Neutralisation  This operation consists in neutralising the free fatty acids, using caustic soda. The process transforms the free fatty acids into soaps. These are no longer soluble in water and can be removed easily by decantation or centrifugal force. The removal of the free fatty acids does not close neutralisation, as the operation also eliminates the phospholipids that are not hydrated at degumming level, and it reduces the amount of metal traces as well as some pigments and minor constituents. [Top] [Home page] De Smet has supplied over 530 bleaching plants Bleaching   Bleaching is the process operation which is carried out before deodorisation.In addition to colouring matters, the bleaching treatment using actived earth will remove residual phosphatides, metals, soaps and oxidation products. Bleaching in 3 stages Bleaching is performed in 3 stages : Initial mixing of oil with bleaching earth under controlled conditions of temperature, acidity and humidity for a specific residence time. Secondly the oil is heated under vacuum with sparge steam to ensure proper mixing with bleaching earth for a specific residence time. Finally the mixture is pumped through hermetic leaf filters with stainless steel mesh elements followed by polishing filtration. Spent cake is dried by steam blowing to remove the oil from the wet cake. [Top] [Home page] DeSmet unique SPARBLEACH The originality of Sparbleach® is that the adsorption of coloring matters by the bleaching earth is enhanced by means of sparge steam resulting in a significant saving in bleaching earth. The Sparbleach® is a two stage vessel. Oil/earth mixure is introduced under vacuum into the top stage where it is heated and continuously agitated by injected sparge steam. The dispersion of earth at optimum conditions of : vacuum temperature combined with steam agitation of the oil mass ensures ideal conditions to start the adsorption process. The bottom holding compartment where the decoloration is completed is equipped with an arrangement of partitions ensuring uniform residence time and sparge steam distributors
Sparbleach® with prefiltration De Smet has developped this new technology, which has now been adopted on a large scale by the industry. This new process is based on the re-use of the spent bleaching earth, without removing it from the bleaching filters. Once the spent bleaching earth is re-used in the filter, it is discharged and evacuated. The prefiltration requires an additional filter.
Combiclean The Combiclean is a further development, which has received a lot of interest of all our customers. The Combiclean is the combination of a Sparbleach® with prefiltration together with a silica pretreatment, followed by a separate active carbon treatment with dedicated filters. This allows the reduction of polluted filter cakes amount. .
[Top] [Home page] De Smet supplied over 110 winterising plants. Winterisation   Winterisation is an operation designed to preserve limpidity and refined oils brightness. The Wintrend® process consists in removing from these oils, mainly maize and sunflower, small quantities of solids that cause cloudiness when the oil is kept at ambient or low temperature. These solid substances can be saturated glycerides or waxes. Thanks to the relatively small amount of solids - between a few hundred and 2000 ppm - winterising is a continuous and, therefore, cost-effective process. In order to obtain an oil with good stability, the wax content needs to be reduced to a level of less than 10 ppm. To achieve this, the variables of time, temperature and agitation require special care to produce oil in a closely controlled range. The process is conducted in four steps:
De Smet supplied over 900 deodorising plants. Deodorising Final stage in refining process Deodorising is the final stage in oil refining. Deodorising removes odoriferous material, free fatty acids and other undesired minor components to produce a bland oil with a good shelf life.  State-of-the-art deodorisingOver the latest years, the aim of a state-of-the-art deodorising became: maximise: - odour, flavour removal - free fatty acid removal - colour reduction (heat bleaching) - peroxides destruction minimise: - losses in essential fatty acids (EPA/DHA) - creation of transisomerisation (TFA) - polymerisation - breakdown vitam. A+D+E Organoleptic & Nutritional Value - Shelf life Final customers require a perfect oil with high organoleptic and nutritional values, even one year after production. Deodorising stages The different stages in deodorising are : - Deaeration - Heating - Deodorising / steam stripping - Heat recovery / cooling - Final cooling - Polishing filtration Top quality products require optimal conditions at all stages. Available deodorising technologies We supply a Continuous Deodoriser, the Qualistock® and a Feedstock change Deodoriser, the Multistock®. For both systems, we can propose the Sublimax Ice Condensing System. [Top] [Home page] Continuous Deodorisers Qualistock® Deodoriser Highly demanding processors The Qualistock® Deodoriser is a new fully integrated compact deodorising system, including a new steam injection concept, in which deaeration, heat exchanging, heating, deodorising/stripping, cooling and scrubbing all take place in one single vessel. The Qualistock® (patented) has been developed for highly demanding processors seeking reliable, consistent and efficient product quality, and is the result of a continuous R&D effort based on the experience of more than 900 deodorising plants.
Qualistock®‘s superior benefits.... 1. Superior Oil Quality Deaeration The first important step is to correctly deaerate the oil to remove the dissolved oxygen with as positive result the limitation of excessive oxidation and polymerisation. Contact Area Deodorisation is a physical process where it is important to optimise the contact area between the steam and the oil.  Remove shorter chain compounds...The purpose is to effectively remove the shorter chain compounds, such as ketones and aldehydes. These are the source of off-flavours and smell in the final product. ..and longer chain compounds It is simultaneously a chemical process where longer chain compounds are thermally cracked by a defined time at deodorising temperature, to be removed during the physical process. Cooling of the oil takes place under vacuum with sparge steam, by means of heat exchange with the incoming oil. These cooling conditions are necessary to ensure a first class refined oil. Actual trends Actually the trend in deodorising is to deodorise at lower temperatures (220-235 °C) and with a deeper vacuum (2mbar) to minimise trans and polymer formation and the loss of valuable minor components like tocopherols. 2. Minimal Oil Losses Reduced losses The neutral oil losses have been substantially reduced compared to conventional deodorisers, thanks to the unique integrated concept of the Qualistock®. Negligible pressure drop The pressure drop in a Qualistock® is negligible, and high vacuum conditions allow deodorising to take place at a lower temperature, which is beneficial for the retention of natural anti-oxidants.  Double steam injection In the Qualistock®, steam injection is effected on one hand through special designed gas-lift pumps and on the other hand through steam injection rings located at the bottom of the tray. Low velocity gases In the Qualistock® the gases loaded with stripped components are moving down in the large central chimney at very low velocity. Furthermore, the Qualistock® is concieved in such a way that the temperature gradiant of the deodoriser vessel is gradually going down from top to bottom. 3. Reduced Steam & Fuel Consumption New design gas-lift pumps The stripping steam is blown into the tray by gas-lift pumps of a new design. The high capacity pumping action enhances rapid circulation of the oil in the tray, and oil at the bottom of the tray is carried to the surface many times during the process cycle, offering optimum contact area. Large heat exchange area Fuel consumption is kept to a minimum thanks to the large heat exchange area of a number of individual coils manufactured from high quality stainless steel pipes of large diameter. Uniform foam layer A large surface area between oil and steam is ensured by the intimate contact within the gas-lift pumps, generating a uniform foam layer creating an enormous contact surface. 4. Fits in Confined Spaces
5. Modular Design All Qualistock® trays are modular. A taylor-made design can be built up out of standard modules, to suit the customer’s requirements. Special options Following special options are available :  Dual-Temperature Deodorising with options:- Low-High - High-Low Dual CondensationFor specific applications we have designed a Low Pressure Drop structured packing (LPDSP).Variable deodorising trayoil bed (shallow-deep)allowing variableresidence time6. Reduced Building & Installation Cost The Qualistock® is self-supporting and supplied with a skirt. Pumps can be installed inside the skirt. The Qualistock® requires only small platforms, giving access to the manholes and sightglasses, which drastically reduces the building cost. Usually, even in cold climates, the Qualistocks® can be installed in the open. Piping is limited due to the integrated vertical concept, which further reduces erection cost and time. 7.Easy Maintenance No high temperature pumps, neither delicate heat exchangers. With a reduced peripheral piping, there is less risk of leaks. Thanks to the low temperature deodorising there is also less build-up of polymers. Designed to operate 24H/day, 7 days a week, 52 weeks a year with-out shut down. Cleaning is limited to once every year depending on the quality and type of processed rawmaterials. 8. Easy Transport The Qualistock® is available in standard diameters from 1,9 m up to 4,2 m. and is usually supplied in one piece, but the possibility exists to supply in two or three segments depending on the off-loading limitations of the customer. [Top] [Home page] Feedstock Change Deodorisers  The Multistock® is a single shell compact column containing several integrated trays or compartments.In the upper part of the Multistock® the oil is heated to deodorising temperature and then cooled in the lower part of the Multistock® Thermosyphon heat exchange This is accomplished with the thermosyphon heat recovery system in which the hot oil after deodorization is used to generate steam, which is condensed in the top tray to heat the incoming bleached oil. In the second tray the oil is heated to deodorization temperature with high pressure steam. In the deodorizing trays the oil remains as a batch in the tray and movement must be induced. This is done by introducing the stripping steam into the tray in a number of gas-lift pumps. Optimum contact area The high capacity pumping action produced results in rapid circulation of the oil in the tray. The oil at the bottom of the tray is moved to the optimum contact area at the surface many times during the process cycle. A large surface area between oil and steam is ensured by the initimate contact within the gas-lift pumps and also by the generation of a thin film at the discharge of each pump.  With this steam injection system, a deeper oil layer improves the circulation rate of the pumps. Therefore, the overall diameter of the Multistock® may be kept within reasonable limits.  After initial cooling in the thermosyphon system, the deodorized oil may be cooled to discharge temperature in a number of ways with the possibility of obtaining some extra heat recovery:
The Multistock® is designed for the factory requiring maximum flexibility in processing different feedstocks daily. Product change is totally automated with the possibility of no production loss and minimum interstock contamination.
[Top] [Home page] Ice Condensing Sublimax  The Sublimax®(patented) is a new generation vertical Ice Condensing technology, optimised specifically for the deodorising process, achieving very low absolute pressures and drastically reducing the running cost of the plant in terms of energy consumption and polluted water flow. Special vacuum production units have been developed to reach lower pressures and operating costs, and at the same time, to reduce emissions by a more efficient condensation of the volatiles. The dry ice condensing system is becoming more and more the standard in new refining plants. In this system, the sparge steam is iced on surface condensers working alternately at extreme low temperatures (around –30°C). The remaining non-condensables are removed either by mechanical pumps or roots blowers in series with a liquid ring pump or by a vacuum steam ejector system (booster). The dry ice condensation system reduces the motive steam consumption but requires extra electrical energy. DC systems essentially consist of two or more freeze condensers containing the cooled tubes, a refrigeration plant for the generation of cold refrigerant which is evaporated in the tubes and a vessel with relatively warm water for defrosting and cleaning of the tubes after a period of freezing.
The Sublimax® has been developed for highly demanding processors seeking reliable, consistent and efficient product quality, based on the experience of over 900 deodorising plants and has been acquired by Cargill, Unilever, Karlshamns, Central Soya, etc... |
