Oil and gas recovery in gas stations refers to the collection of volatile gasoline oil and gas in the process of loading and unloading gasoline and refueling vehicles, or reducing oil and gas pollution by one or two methods such as absorption, adsorption or condensation, or changing oil and gas from gas to liquid and then to gasoline, so as to achieve the purpose of recycling.
Oil and gas recovery is a new technology of energy saving and environmental protection. Using oil and gas recovery technology to recover oil and gas discharged during storage, transportation, loading and unloading can prevent air pollution caused by oil and gas volatilization, eliminate potential safety hazards, and reduce economic losses by improving energy utilization rate, thus obtaining considerable returns.
2. What are the oil and gas recovery equipment at the gas station?
Oil and gas recovery equipment in gas stations is generally divided into three types: primary recovery equipment, secondary recovery equipment and tertiary recovery equipment, namely:
1. Primary recovery equipment: quick connector and cover for returning oil and gas, flange valve connector for unloading resistance, etc.
2. Secondary recovery equipment: oil-gas separation joint, coaxial short hose, pull-off valve, coaxial long hose, oil gun for oil-gas recovery, gas-liquid ratio control valve, etc.
3. Tertiary oil recovery equipment: mainly some oil and gas emission treatment devices.
Third, there are several methods for oil and gas recovery in gas stations.
1, adsorption method
The separation of oil and gas from air can be realized by using the adsorption force of adsorbents such as activated carbon, silica gel or activated fiber to the oil-gas/air mixture. Oil and gas pass through adsorbents such as activated carbon, and the oil and gas components are adsorbed on the surface of the adsorbents, and then desorbed under reduced pressure or steam, and the enriched oil and gas is pumped to an oil tank by a vacuum pump or liquefied by other methods; However, adsorbents such as activated carbon have little adsorption power to air, and the unabsorbed tail gas is discharged through the exhaust pipe.
2. Absorption method
According to the solubility of each component in the mixed oil and gas in the absorbent, the oil and gas are separated from the air. Generally, lean oil such as diesel oil is used as absorbent. Generally, oil and gas are in countercurrent contact with the absorbent sprayed from the top of the absorption tower. The absorbent selectively absorbs hydrocarbon components, and the unabsorbed gas is discharged through the flame arrester. The absorbent enters the vacuum desorption tank for desorption, and the enriched oil and gas is absorbed by the oil product.
3, condensation method
Using the vapor pressure difference of hydrocarbon substances at different temperatures, the vapor pressure of some hydrocarbons in oil and gas is supersaturated by cooling, and the supersaturated vapor is condensed into liquid state to recover oil and gas. Generally, multi-stage continuous cooling is adopted to reduce the temperature of oil and gas and condense it into liquid for recovery.
4. Membrane separation method
The special polymer membrane has the characteristic of preferential permeability to hydrocarbons, so that oil and gas molecules can preferentially permeate through the polymer membrane under the drive of a certain pressure, while air components are intercepted and discharged, and the enriched oil and gas are transported back to the oil tank or liquefied by other methods.