The need for effective filtration & pre treatment

Most biodiesel is made from waste vegetable oil (WVO) collected from catering and food production facilities,or from virgin feedstocks.

The WVO often contains high levels of Free Fatty Acids, moisture as well as solids, other impurities and contaminants. The solids can be filtered out using correct filtration procedures. The water must be removed by heating the oil to above 212°F (100°C) for an extended period to drive the water from the oil.

WVO typically contains from 2-5% free fatty acids. If the free fatty acids are above this amount, it is very difficult to produce biodiesel without an acid esterification process. The free fatty acid number is determined by a titration process. A full description of this process is available on request.

A common problem with biodiesel producers is instead of a clear separation between the biodiesel and the glycerine after the reaction and settling process, they end up with a semi-solid, gelatinous mixture that cannot be purified and used as fuel. This is an indication that the oil contained excessive free fatty acids and/or water.

Raw vegetable oils that are produced by pressing oilseeds such as rape (canola), mustard or soybeans can be converted to biodiesel. The free fatty acid level of these raw oils is usually 0.5% or less, which is low enough not to pose a problem. However, the oil may contain gum compounds that can create sludge deposits in the processing equipment and can make it difficult to separate the glycerine at the end of the reaction.

Download a datasheet on WVO filtration