Crude oils that are transported to refining or markets tend to separate into heavier and lighter hydrocarbon layers over time. The heavy hydrocarbons that deposit on the bottom of tanks are known as “tank bottoms”, or “sludge”.
Tanks bottoms consist of hydrocarbons, sediment, paraffins, and water, and accumulates on the tank floor as a viscous gel. The sludge must be removed regularly for several reasons: to restore tank capacity, comply with inspections policies, prevent clogged suction lines from deposited sludge, and to avoid damage to downstream processes.
There are two Main Challenges for sludge produced in Tank Terminal facilities:
1. Paraffinic Cluster
Paraffins create strong clusters and layers, which have also to be broken from oil water emulsions.
2. Asphaltene In Tank.
Asphaltenes are natural surfactants, and when the sludge removed from tank with water asphaltene create strong polar emulsion with oil and water. In order to separate oil and water, asphaltene bond has to be broken by non-ionic demulsifier or process (Molano, 2018).
The properties were tested at the Long Beach University Laboratory indicated that the
sludge has Total Petroleum Hydrocarbon (TPH) concentration - 293670 mg/kg and
Polycyclic Aromatic Hydrocarbons (PAH) concentration of 117520 mg/kg.
Use diesel or kerosene as solvent to help mobilize heavier hydrocarbons into a medium grade crude in the likes of to make Marine/Bunker Fuel. This process is more economical because produces valuable product to offset opex or use additional income to properly process water and solid residues from the sludge.
Additionally, solid residue can be further collected using a flocculant to then process the solids in digester for effective degradation of TPH and PAHs using prolific hydrocarbon digestion bacteria.
GreenZyme Detergent Separator is also an option for Hydrocarbon polishing. We have designed a special centrifuge to use and recycle GreenZyme detergent while recovering hydrocarbon product created with less that 6% water content.
After separation obtained product has properties of Marine Fuel and can be sold as a valuable product.