Microbial colonisation presents itself as a jelly-like mass that can block filters in fuel dispensing equipment and vehicle engines.
Preventing Microbacterial Growth in Diesel Fuel
The introduction of bio products into modern diesel fuels has created a need for fuel storage systems that combat hgroscopic (water absorbing) properties which might otherwise support microbacterial growth, according to Cameron Forecourt.
Water has always been the enemy of mineral fuels, but has historically been ignored as it fell out of suspension to accumulate at the bottom of tanks to be drawn-off safely and effectively in traditional diesel fuel formulations.
Today's fuels, however, contain a mixture of mineral and biological material; with bio components creating particular difficulties since their hygroscopic nature is an attractive environment for different types of microbe that live in water but also feed off hydrocarbons in mineral fuels.
The introduction of bio matter in mineral fuels means that water is now also more easily miscible with mineral fuel by way of the hygroscopic nature of the bio products. The result is that microbes can now more readily exist within bulk fuel storage.
Microbes present multiple barriers to effective fuel storage:
- Microbial colonisation presents itself as a jelly like mass that can block filters in both the fuel dispensing equipment and the vehicle’s engine.
- Microbes excrete waste that can build up in the bottom of the tank and quickly deteriorate the quality of the fuel as well as affect the inner skin of the fuel storage tank.
- The presence of microbes in fuel storage can affect the quality of the fuel and impact the chemical specification.
- Microbial contamination can result in uneconomical and poor vehicle running and can damage the vehicle injector system.
The problem is not as widespread as one might expect. When bio mass was first introduced into mineral fuels it was predicted that contamination would become a significant and on-going issue. Certainly, there is evidence that it is an on-going issue, but it is far less significant than was first expected. What is prominent however is the random way in which contamination problems present themselves.
As with everything, prevention is always better than a cure - and in this instance far, far, cheaper, and the following measures have been proven to make storage more effective:
- Using a reputable fuel supplier with a recognisable quality management system (QMS).
- Using fuel quickly - and ideally, within 1 or 2 months of delivery to reduce the timeframe for any potential contamination.
- Storing fuel in a modern, totally enclosed, fuel storage tank.
- Operating a tank to a reasonably low level before accepting a new load of fuel.
- Testing fuel for contamination on an annual basis and, more regularly, when problems are suspected.
- Reacting to a suspected contamination problem promptly.
Despite the plethora of available, commercially advertised solution to fuel contamination, at Cameron Forecourt we believe the only absolutely effective means of eradicating contamination is to empty and manually clean the interior of tanks and associated pipework.