Fuel polishing is the technical cleaning process used to remove or filter microbial contamination from oil and hydrocarbon fuel in storage. It is essentially the removal of water, sediment and microbial contamination from such fuels as diesel, red diesel and biodiesel.
A fuel evaluation must be undertaken before fuel polishing is started so that the precise problem can be rectified with a focused solution. A second fuel check must be performed after the fuel polishing has been finished to affirm the problem has been fixed.
Sources of Contamination
Over any given period of time fuels in storage can develop pools of sludge, sediment and water caused by microbial contamination. This contamination can quite easily find it’s way into fuel at one of the many exchange points in its journey from source to end user. Left untreated, the levels of contamination worsen to the point where damage to machinery, pumps and engines is likely. When fuel is pumped into a tank condensation, atmospheric absorption, and a faulty tank are usually the main causes of fuel contamination. Microbes find their way into fuel and cause problems as they multiply and grow.
Symptoms of Diesel Bugs
The symptoms of diesel bugs are easy to find. Important things to check over and look out for are:
- Worn Fuel Injectors
- Blocked Filters
- Corroded Tanks
- Engine Failure
Microbial contamination is heavily accelerated when higher biodiesel content occurs along with lower sulphur content.
Water in Fuel
Almost everything on Earth contains elements of water and with fuel there is no exception. Albeit very small amounts exist in fuels to start with, but stored fuel will become a breeding ground for the microbial bacteria and over time, the levels of damage change from dissolved to emulsified and finally free.
Dissolved – Dissolved water in fuel is the presence of water, but unnoticeable to the eye. The water continues to develop until saturation point where water visibility begins.
Emulsified – At the point of saturation, a cloudy appearance will be the tell-tale sign that the water/fuel oil mixture has become emulsified.
Free – The most developed stage of fuel contamination is when free flowing puddles of water appear within the stored fuel. At this point, bacterial contamination and growth is boosted.
