Biodiesel Storage

When storing B100 biodiesel for blending into petrodiesel, many of the same factors taken into consideration with conventional diesel fuel storage also apply, but on a greater level. What are some of these considerations for storing B100 biodiesel?

• Exposure to air and light causing sludge formation in the fuel over time
• Water absorption leading to high liklihood of microbial contamination

Beyond B100, biodiesel blends (even the low-level blends that are only a small proportion biodiesel to diesel fuel), are just as prone to problems from these same causes. 

Water loves biodiesel

Water gets into regular stored diesel just through processes of natural condensation, building up in storage tanks and forming both free water layers under the fuel and, in many cases, layers of microemulsion within the fuel.

Biodiesel, on the other hand, likes to emulsify and hold on to water because of the presence of mono- and di-glyceride molecules that are often left over from its processing.  When this happens, the emulsified water can affect how the bio-blend burns while contributing to corrosion of storage tanks. It can even freeze when it exists in biodiesel stored in cold winter climates.

Not to mention how microbes love it when water in fuel hangs around.

Microbes love stored biodiesel even more

Being a converted fat (converted from any number of fats and oils like soybean, canola, chicken fat, etc.) makes it extra prone to both the effects of water and to microbial growth.  Microbes love biodiesel as a food source and it doesn’t take much for stored biodiesel blends, even blends with only 2-5% bio (that are labelled as regular diesel) to become a microbe breeding ground.  And if you’re a fleet or other professional who deals with fuels for a living, you know that microbes in fuel are bad, bad news.

Suspecting problems with stored biodiesel

Your stored biodiesel might have one or more of these problems if you can detect water in the storage tank, if your rate of filter use spikes (as filters becomes plugged more easily with sludge or microbial biomass) or if the performance metrics of your equipment suddenly changes.

If you're aware enough to  notice these changes, this only means you now have to fix the aftermath of the problem. And just like with your health, it’s more problematic and expensive to correct stored biodiesel problems than it is to use a little preventive maintenance and keep them from happening.