Types of raw material
The first years of BioDiesel production were characterised by the utilisation of renewable raw materials. However, faced with the constant increase in the worldwide demand for food, it became necessary to open up alternative sources of raw materials. In the meantime, BioDiesel production based on residual and waste products such as used cooking oils, animal fats and trap grease has established itself as the way forward – last, but not least, due to the BDI multi-feedstock technology that we keep evolving further. However, there is still a huge potential of unused raw materials out there that needs to be made accessible. BioDiesel production from waste materials thus fulfils two essential functions: safe waste disposal and energy production.
The utilisation of animal by-products that constitute hazardous materials in a legal sense entails additional official procedures and monitoring and control mechanisms at the plant. Using BDI multi-feedstock technology also enables you to utilise hazardous materials (category 1 and 2 animal fats) in BioDiesel production. The EU has permitted this use in a regulation dating from 2005.
Used cooking oil
In addition to animal fats, used cooking oil is also available in large quantities, with every household producing several kilograms of used cooking oil every year. However, only 5-10 percent of this amount is collected for further processing in a structured way. By far the largest share is disposed of via the sewage system, causing problems for purification and waste water treatment plants. The potential for producing high-grade BioDiesel from used cooking oil thus remains enormous.
Wherever cooking fats or oils are used – for instance in large-scale kitchens, restaurants or supermarkets – oil may be filtered as a precious raw material from waste water. To do this, a grease trap must be installed at a point where it stops the fat from entering the sewage system. Where specialised technologies are used, the collected grease is excellently suited for producing high-grade BioDiesel while also solving what is a genuine waste problem for many municipalities.