Can heavy fractions with a flash point of 78°C be stored in internal floating roof tanks?
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A C9 project has been designed, whose products contain heavy components with a flash point of 78 degrees Celsius; 30% of these products is naphthalene. It is necessary to heat the contents in the tank to 80 degrees Celsius and maintain that temperature. What type of tank is used to store the reconstituted components? Code for Design of Oil Depots 6.0.2: For above-ground vertical oil tanks used to store Class A and Class BA oils, floating roof tanks or internal floating roof tanks should be selected; floating roof tanks shall be equipped with a secondary sealing system. For covered soil tanks and manhole tanks used for storing Class A oils, as well as tanks used for storing other types of oils, fixed-roof tanks are preferred. ”——————I believe the heavy fractions should be stored in dome tanks, where they can be heated and kept warm ； However, since the owner has already carried out a similar project using internal floating roof tanks for heating and insulation, I don’t understand why. Please advise – can internal floating roof tanks be used? There is a heater inside the internal floating roof tank, and it heats the temperature to 80 degrees Celsius – will this have any adverse effects on the internal floating disk?
An internal floating roof should be used. The flash point of this component is 78°, which indicates that vaporization occurs at this temperature, meaning there are gaseous components present. Since this tank needs to be heated to 80°, the absence of an internal floating roof will inevitably lead to evaporation losses of this component, posing safety risks.
Please explain the specific uses of storage media
Heat to 80 degrees; an internal floating roof is appropriate
No internal floating disk is required; for heavy aromatic hydrocarbons C10, heating to 60 degrees is sufficient, and since they contain naphthalene as well, there is virtually no loss. If the temperature inside the tank is very high, it has no effect on the floating disk; however, if the heating temperature is not sufficient, crystallization on the walls and bottom will severely affect the floating disk. Additionally, pipeline purging also has an impact on the floating disk.
Naphthalene is a colorless flaky crystal with a melting point of 80.5°C and a boiling point of 218°C; it has a distinctive odor and is prone to sublimation. Insoluble in water, soluble in hot ethanol and ether. Naphthalene is an important organic raw material in the chemical industry, and it is also commonly used as a moth repellent. &Nbsp; Naphthalene is a crystal with a melting point. During the heating process, the temperature of solid naphthalene gradually increases and it begins to melt ； The melting process: during this phase, heating continues, but the temperature remains constant; this temperature is the melting point of naphthalene, which is 80℃ ； Continue heating; once the naphthalene has melted, the liquid naphthalene will continue to heat up as further heat is applied. As mentioned above, the heavy fraction contains 30% naphthalene, with the remaining 70% being macromolecular substances. The melting point of naphthalene is 80 degrees Celsius, which seems to be contradictory to the flash point of the heavy fraction, which is 78°C These data were provided to me by the owner and the process team; I am responsible for the storage and transportation design of the tank area for this project, and I have doubts about the conditions specified by the process team.
The reconstituted fraction is a product of the C9 project; it comes out of the resin oil tower, is cooled to 60 degrees in a cooler, and then sent to the reconstituted fraction storage tank. There, it is heated to 80 degrees before being sent out
Reply to 6# lvshan2004-9: The flash point is the lowest temperature at which a flammable liquid or solid can release enough vapor to form a flammable mixture with air at the surface of the liquid or solid in its container. It has no direct relation to the boiling point of the substance. Also, doesn’t naphthalene dissolve at a temperature lower than 80 degrees?