Heat treatment
Some low quality feedstocks like animal fats, POME, UCO, can cause problems because of difficult to remove P and metals and also sometimes because of too high organic chlorine in the feedstocks after classical pre-treatment.
Based on extensive research on difficult raw materials, the Desmet R&D team has found a relatively easy way to make the pre-treatment much more effective for these feedstocks.
Extensive R&D research and industrial trials has shown that adding a high temperature heat treatment (HTT) between the degumming and bleaching step, makes the removal of P and metals much more easy and efficient. As a result an important reduction (up to more than 50%!) can be obtained in the amount of bleaching earth needed in the final bleaching step.
As an additional benefit, the heat treatment also allows the partial removal of organic chlorines, that are almost not removed in a classical pre-treatment.
The patented heat treatment section can be added as an option for clients that wants to use these difficult feedstocks as part of the feedstock blends. However, it’s also possible to add the heat treatment as an add-on to an existing pre-treatment plant as an upgrade of the existing plant to treat low quality feedstock blends.
How does it work
The oil coming from the degumming treatment is dried and buffered and then the oil is pumped to the heat treatment reactor. The oil is first heated by heat exchange and then by thermal fluid to the required temperature for the thermal treatment.
After a uniform retention time at higher temperature in the reactor, the oil is then again cooled by heat exchange and water cooling, to the required temperature for the further pre-treatment – oil washing followed by bleaching.
The above process has been patented by Desmet, and more details can only be disclosed upon specific request. It should be clear that the process offers numerous benefits for pre-treatment: not only for difficult feedstocks, but also for easier feedstocks such as UCO and vegetable oils. It is possible to achieve better and more consistent quality specifications for the end product with significantly fewer chemicals and less bleaching earth, resulting in a much lower OPEX for the overall pre-treatment. Additional benefits are less filter aid consumption, less steam consumption and effluents due to longer filter cycles and less disposal costs for the spent filter cakes. On request, a savings calculator is available to evaluate the benefits of the heat treatment for your specific project.
