Quality of Fuel oil and Sludge

It is difficult to define, what may be good for one consumer is unsuitable for another. We should keep this fact in mind, since the quality and condition of many heavy fuel oils produced by the refinery are changed before they are ultimately burned. This is primarily due to the handling, use, operation and type of equipment used, since the advent of the petroleum refining, the refining processes have changed considerably. Today, there are many variations in residuals owing to the methods of refining and blending that create problems for the consumer and equipment manufacturers.

Formation of Sludge

The formation of sludge is due to the blending of fuel oils in the refinery which tend to coagulate forming large particles of solids which settle down faster. Organic precipitation of solids from the liquid oil is due to the heavy liquid, high-molecular weight compounds present in the residual which may be insoluble during blending. In general, sludge contains emulsions found in tank bottoms, suspended heavy chemical compounds, insoluble solid oxidation products, organic products of precipitation, dirt, rust and scale. Major refineries, power plants and all industries in the world are having sludge accumulation in the order of hundreds of thousands tonnes, whose value run into several million of dollars.

The coagulating nature of the sludge makes combustion of the large particles a difficult job for a liquid burner. Sludge gets carried into the fuel lines, leading to fouling of filters, strainers and burners tips, making it difficult to maintain stable flame conditions, resulting in build up of carbon-rich deposits. These deposits often deflect the flame against the refractory walls or water tubes, causing unnecessary outages. Cleaning out sludge from tank bottom, requires extensive maintenance cost and down time.

Sludge formed by the peroxide free radical chain reaction will be very thick and hard at the bottom and very gummy as the sludge layer ascends. Sludge consists of high molecular weight carbon compounds, metals and oxides like Vanadium (from the catalytic cracking of petroleum) and its ferrous oxide (usually as rust), water molecules, some halogens, dirt, scales etc. Usually the sludge will be negatively charged, because the metal ions present in the sludge is positive and the polymerase gum, which has some free radicals, forms a mesh surrounding the metal ions, along with water molecules and dirt.

There is a general notion that no solvent can dissolve fuel oil sludge once it has formed and unless excessive quantities of solvents are used, as several times the quantity of sludge present, would be necessary. E-OIL comes in to play a very vital role in sludge management to save valuable money.