hidden sludge hazards

These three pictures show buildup in a tank that stored petroleum diesel for heating a home. This fuel tank was taken out a basement of a house, and we assume it served the house for approximately 20 to 25 years.

Our plans are to use this tank for settling and heating recycled fryer oil for the process of making biodiesel.

When we cut out the hole to make a lid for this tank, we found the sludge buildup was as much as ½ inch thick.

From a little research, we learned that contamination, oxidation, chemical incompatibility, water and microbes all contribute to the process of polluting and deposits that form tank sludge.

Biodiesel is a solvent that cleans debris out of tanks and fuel lines. Sludge from the petroleum diesel deposits settles in the fuel tank and fuel lines, and loosens via the use of biodiesel.

Tanks sitting stationary for sometime (e.g. farm equipment, construction equipment, etc.) may have a buildup of sludge and may require you to change fuel filters a few times in order to rid the tank of the sludge. Of course, the buildup pictured accumulated over time in a sedentary tank.

With the colder weather setting in, two families we know who switched to biodiesel for home heating recently had to replace the filter and drain a couple of gallons of sludge off.