Posted 21st January 2020
An ever-increasing issue over the course of this winter has been clogging filters. It hit the industry seemingly at random but at last, we have some clue as to what the cause might have been. New regulations to increase the biodiesel percentage up to 7% have required the use of animal tallows in fuel production.
Recent B7 Biodiesel is clogging up fuel filters on diesel dispensers across the country. Especially where there has been a particularly chilly night! Normally winter diesel comes equipped with anti wax agents that prevent this build of diesel waxes. However, recent changes to Biodiesel 7 have called for increased use of animal fats in diesel fuel.
These animal fats have a much higher saturation than standard vegetable oil. Therefore, the stored fuel has a higher cloud point than standard winter fuel. This means that the tallow starts to crystallise at a much higher temperature than normal. So cold weather is increasingly affecting gas oil fuel tanks as early as November and December.
Tank Services have visited sites experiencing these issues and have observed the waxing first hand. Often our clients are very high demand users so they have a high throughput of fuel. That high usage eliminates the time required for diesel to stagnate and grow diesel bug. That’s why we think it is highly unlikely that filters are clogging up because of microbial contamination.
Unfortunately, the problem being experienced with diesel tallow can’t be solved by running the fuel through filters. Whilst the filters will catch the gel, they will clog just as heavily as a diesel dispenser filter. Adding to that, the filters on a fuel polishing system are much, much more expensive than those on a standard diesel dispenser. So it is far more cost-effective to replace the filters on the dispensers than to try and process all of the fuel through a diesel conditioning system.
There aren’t any known solutions to this problem as of yet but there are a few unproven suggestions out there. We go into further detail on these solutions in our article about this issue found here. However, we suggest gently warming the tank or the filter area to prevent the gel from building up on the filter. Other suggestions include adding kerosene to the fuel although not recommended due to the sensitivity of common rail engines.
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