The feedstock challenge

The processing of oils and fats into biofuels, regardless of whether they are waste oils or crude vegetable oils, requires pretreatment before the feedstock can be utilised in a biodiesel or hydrogenation process (HVO, HEFA, sustainable aviation fuel [SAF] or renewable diesel).
This step is crucial for the economic, efficient and reliable operation of the downstream process.
The pretreatment requirements depend on two parameters. First of all, the question should be asked which feedstock is to be processed.
It makes a huge difference whether a crude vegetable oil or a fatberg from the sewage system should be processed.
Secondly, the tolerance of the downstream process regarding various impurities should be examined. Figure 1 shows a comparison of pretreatment process steps for vegetable oil and waste feedstock as well as for a hydrogenation process and for a biodiesel process. As one can see, more effort is necessary to prepare such a waste feedstock for the use in an HVO process, as feedstock quality requirements are stricter for HVO-processes.
Biodiesel versus HVO
Both biofuels use the same feedstock, based on...