Crude-oil Storage Tanks

Waste material snch as tank bottoms from crude oil storage tanks constitute a large percentage of refinery solid waste and pose a particularly difficult disposal problem due to the presence of heavy metals. Tank bottoms are comprised of heavy hydrocarbons, solids, water, rust, and scale. Minimization of tank bottoms is carried ont most cost-effectively through careful separation of the oil and water remaining in the tank bottom. Filters and centrifuges can also be used to recover the oil for recycling. 

Chemical reaction or polymerization High-temperature coking Corrosion Buildup on internal reactor surfaces, and in crude-oil storage tanks, is often encountered Carbonaceous material is deposited on walls of furnace tubes Common problem in heat exchangers... 

Figure 10. Typical piping arrangement for a crude oil storage tank.

Emerson Gumming, Inc., eventually bought the rights to the Sohio process and produced a variety of microspheres. Union Carbide was licensed to produce the phenolic microspheres offered under the name Phenolic Microballoons (Table 15). When Phenolic Microballoons are introduced into a crude-oil storage tank, they form a fluid seal that rises and falls with the level of the oil. A continuous vapor-barrier seal is formed, which reduces evaporational losses up to 90%. Tests have been conducted under various mechanical and weather conditions and with crude oils of varying vapor pressure. 

Excellent resistance to mild acids, mild alkalies, salt water and freshwater. Poor solvent resistance. Used for crude oil storage tanks, sewage disposal plants, and water works. 

Combination rate of rise and fixed temperature The author has even observed the provision of a tensioned string connected to a pressure switch that has been provided as detection over the vapor seal of a floating roof crude oil storage tank. Although this method may be considered primitive and inexpensive, it is eflFective and beneficial compared to the option of no detection. 

Rotation of floating roof of crude oil storage tank Operation Crude oil storage tank Oil Physical damage Control failure... 

---