AXI Technology Solves Water Contamination of Underground Fuel Storage Tank

Report on 9,000 Litre Unleaded Underground Storage Tank Clean
30^th November 2005, Plymouth, U.K.

Introduction

E&S Fuel Improvement Systems were asked to attend site by Wyatt Engineering Fuel Services and use our Algae-X fuel polishing technology to deal with water contamination within a 9,000 litre underground unleaded storage tank. At our request the tank contained approximately 5000 litres of fuel.

Initial Sample

Before commencing the cleaning and before the addition of the AFC705 Fuel Catalyst a sample was taken from the bottom of the tank. Inspection of the sample revealed the following:

• A large amount of free water.
• Suspended within the water was a large amount of fine sludge that settled out over time.
• Large amounts of rust particles.
• The fuel itself was slightly hazy and brownish in colour.

Cleaning

AFC705 was added to the tank at the ratio of 1:2500 (double dose), and the fuel was initially passed through the coalescer, magnetic fuel conditioner and one water block filter. The coalescer was drained regularly and the water and particulates were allowed to settle out before any unleaded was put back into the tank.

The pick up pipes position was changed frequently during the process to ensure as much agitation of the tanks contents allowing for maximum removal of contaminants. Regular samples were taken from after the water block filter, when these samples started to appear bright and clear to visual inspection the flow was changed to enable the fuel to be passed through a further water block filter for final polishing of the fuel. This was achieved after 2,500 litres. The fuel was then cycled through until a) the level of contaminants drained from the coalescer had been reduced to an acceptable level of rust particles (it would not be possible to remove 100% of small rust particulates from this particular tank, this was explained to the customer at the time), b) No free water was present in the samples drained from the coalescer, c) the sample taken from after the final water block filter was clear, bright and free from any visible contamination.

Final Sample

A final sample was taken from the bottom of the tank in the same manner as the initial sample. The sample was found to be clear and bright and clear of water. A greatly reduced number of rust particulates were present, however it was explained to the customer that the total removal of these particles would be virtually impossible. However given their nature in that they settle quickly to the bottom of the tank, they should cause no problems to his installation.

The customer was left with the remainder of the AFC705 catalyst and instructions to add this to the tank when he takes his next delivery and to ensure that his next delivery fills the tank.

Microbial Contamination

A test was carried out on both the initial and final sample using a liqui-kult test kit. The initial sample showed a light contamination and the final sample showed no contamination.

Recommendations

The following recommendations were explained to the customer on site. • Dosing of all tanks with AFC705 at a rate of 1:5000 every quarter. • Keeping his storage tanks as full as possible to prevent condensation. • A regular sampling procedure with a simple visual check to identify any potential problems quicker. The customer was shown our FS100 sampling pump. Conclusion It can be clearly seen from the photographs of the before and after samples that the mobile tank cleaning machine in conjunction with the AFC705 in a little over four hours on site has fully restored the fuel within the customers tank to its original state. This has saved on the costly disposal of contaminated fuel and the hazardous, time consuming, expensive and inconvenient way of cleaning the tank by putting someone inside which was the alternative. Provided the customers adopts a regime of preventative rather than reactive maintenance (regular dosing with AFC705) the need to carry out a full cleaning job such as this is greatly diminished.