Enzimatic Processes Development for Oil Degumming Residues Utilization

The oleaginous crop sector of Argentina is one of the biggest and more efficient of the World, and is a very important part of the country economy. The oil seeds industry produces as primary products the vegetable oil and the meal, and has incorporated in the last decade the production of biodiesel in large scale. The vegetable oil processing, either for edible uses or biodiesel production, requires the separation of phospholipids. This step is commonly known as degumming. The ´gums´ represents approximately 5% of the treated oil, and therefore is an important by-product in an oil industry. It is very important to find applications for this product that typically contains 30% of oil, 40% of phospholipids, and 30% of water.

Today, this by-product is often a problem due to the lack of market and applications in which it can be used. Therefore, it’s an important issue to find new routes in which this stream can be transformed in an added-value product.

 It is known that it is possible to obtain free fatty acids from the degumming residues by hydrolysis using a strong acid, such as sulphuric acid. However, this treatment is extremely aggressive and leads to the generation of effluents that are difficult to treat, and also, gases emissions and corrosion throughout the process. This is a severe environmental problem.

One alternative is the use of enzymes, such as the phospholipases, that selectively break certain bonds in the phospholipid molecule.

In this work, enzymatic catalysis is used to transform the phospholipids present in the gums by hydrolysis, leading to the production of materials that can be transformed in biodiesel.

The objective of this work is to develop enzymatic processes to treat the degumming residues, recovering the occluded oil in the emulsion and the fatty matter present in the phospholipid, either as fatty acids, or mono and di-glycerides. These compounds are then used to obtain biofuels or in the oleochemistry industry.

The study involved a systematic search for solvents in order to fluidize the emulsion minimizing the addition of the chosen solvent. The raw material was fully characterized, and reactions catalyzed by phospholipases A and C were carried out. The effects of enzymes concentration, temperature and solvents were addressed. Products were characterized by GC, HPLC, FTIR, P analysis by XRF and colorimetric spectrometry, and CHON elemental analysis.

It was found that it is possible to obtain a mixture of fatty acids and di-glycerides that could be transformed to high quality biodiesel.