The process of recovering oil from crude/product storage tank bottom sludge addresses environmental concerns, minimizes waste and arguably poses one of the most challenging questions in separation technology. Having said that, PT-MC offers a system that complies with the standard practices of the Environmental 3R’s – Reduce, Recycle, Re-use. Not all waste products can be reused or recycled completely, therefore there is a need to find efficient methods to remediate and reduce waste volumes for environmentally acceptable and efficient disposal. PT-MC treated oily waste is:
- Reduced (minimized) to solids by removal of liquids, and
- Recycling of Oil and Water, and
- Re-use of oil as a product with water returned to nature.
PTMC’s Sludge Liquid Treatment system involves a mechanical oil–sludge treatment plant which uses thermo-mechanical processes to separate the oil-sludge into its primary components. The treatment process generally involves the following steps:
Sludge Preparation and Conditioning
Sludge preparation and conditioning involves heating of sludge, breaking down solids, fluidizing, blending, mixing and homogenizing of sludge to achieve consistent and to maintain suspended mixture. The sludge is homogenized and conditioned in conditioning tanks via mechanical agitators which fluidizes solidified oily sludge hence making it pumpable to the next phase of separation.
Mechanical Screen Separation
Linear motion vibratory Mechanical Shakers are used to screen off solid particles such as rust scales, stones, sand and other foreign debris. Generally wired mesh screens are used at this stage of separation.
Hydrocyclones, used in conjunction with mechanical shakers, forms a vital intermediate step in the separation process. Hydrocylones are designed for separating solids from liquids and are successfully used in a broad range of industrial and environmental applications. Coarse particles separation takes place at this stage of oil-sludge treatment.
Decanter Centrifuge Separation
The high G-force generated by a centrifuge provides further effective separation of solids from liquids. Centrifugal force moves solids from the center to the bowl walls where it is accumulated.
Oil and Water Recovery
The liquid mixture is sent through a series of floatation processes and settling processes, resulting in the recovery of oil and water with oil floating on top and water settled down at the bottom. The recovered oil is returned to the refinery, while the recovered water is sent to the water treatment facility.