What do I need to know about long term diesel storage?
Quite a bit of our business at Star Oilco is fueling back-up generators, emergency water pumps and other long term off-road diesel storage requirements. In Oregon B5 diesel or 5% biodiesel blends are required by state law. This means that most off-road diesels and heating oils are ultra low sulfur diesel with a small quantity of biodiesel in them. That means long term storage is a proactive thing. You can’t just hope and wait to see what the fuel begins to look like year over year of storage.
Here is a technical document from BP on the subject which runs through the specifics of long term storage and what causes fuel to degrade when stored.
BP Fuel News – Long Term Storage of Diesel
For our customers we recommend that you check the tank bottom fuel quality on an annual basis to make sure the product looks good. If the tank has sat for years and is dark in color (good diesel is bright and transparent you will notice if it is in bad shape) we recommend pumping the tank out at least partially and replacing with fresh fuel. Often you can also hugely improve the quality of the fuel by polishing the fuel. Polishing being when you circulate fuel from the bottom of the tank through a pump and filter repeatedly removing any sediment or growth from the fuel and then place this fuel back in the same tank.
For stored fuel you also want to make sure it is stabilized and has a biocide in the fuel. Stabilizers prevent the oxidation of the fuel and prevents the effect of metals like lead, copper and zinc that can react and cause degraded fuel. Metals like lead, copper and zinc can degrade diesel fuels if they come in contact with fuel. With heating oil systems with a return line for instance the fuel is flowing through a copper line to the furnace and then back to the tank in a return line. Biocides prevent biological activity in the tank from starting. In scenarios where micro-organisms like algea, bacteria, yeasts and other bugs are growing in your fuel, biocides can kill this growth. It is still important though to remove the residual grit and other contaminants that are the hallmark of bugs growing in your tank. Usually you remove them by filtration or total turn over of the fuel. If your tank absolutely has to be clean you can contract a tank professional to enter the tank and physically clean the tank bottom or reline the tank with either fiberglass or an epoxy resin.
In events where water finds it’s way into your storage tank, that as well can be corrected by pumping the tank bottom. Additionally you want to put in an absorbent material designed to absorb water and not fuel. If your long term storage tank has water and you are not planning to burn 100% of the fuel in the near future DO NOT add anything that removes water by distributing into the fuel. Adding a “fuel drier” that actually pushes the water into solution with the diesel will worsen the longterm quality of your fuel not improve it. That water is where bugs find their home to grow in fuel.
Feel free to call us with any questions you may have about long term storage of diesel. Star Oil can also deliver treated diesel ready for long term storage complete with Hydrotex PowerKleen Premium Diesel additive to improve the long term storage quality of your fuel. For biocide we use Valvtect BioGuard fuel microbiocide to kill any possible biological activity and prevent any chance of it starting.
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