Gasoline recovery systems

FIGURE 18.6 (a) Single-pump and (b) dual-pump gasoline recovery systems. 

Bjorklund, R. A. and Ryason, R. R. 1980. Detonation-Flame Arrester Devices for Gasoline Cargo Vapor Recovery Systems. JPL Publication 80-18. Jet Propulsion Laboratory, Pasadena, CA... 

MTBE) and benzene, toluene, ethyl benzene, and xylene (BTEX), which are primary components of gasoline. Groundwater Recovery Systems, Inc. (GRS), is the sole licensed manufacturer of the OXY I system. Matrix Biotechnologies has had involvement with technical aspects of the units and is also a vendor of the technology. 

Like dispensing hoses, nozzles must be made specifically for methanol fuel. Gasoline nozzles usually contain aluminum parts and elastomers that are not compatible with methanol. Most gasoline nozzles will function for a time, but even when they are working, they are putting corrosion products directly into the vehicle. Emco-Wheaton makes a dispensing nozzle compatible with methanol and configured for vapor recovery systems. 

What is the fraction of gasoline recovered by the vapor recovery system that reduces the gasoline concentration in the vapor from saturation at 75°F to 35mg/L ... 

Although many aspects of a solvent-vapor system apply to gasoline recovery, there are some fundamental differences. The recovery of a solvent is a relatively simple process in which an adsorbable vapor is removed from non-adsorbable air whereas the recovery of gasoline involves a selective separation of ingredients that are more adsorbable from ingredients that are less adsorbable. Because of this, the arrangement and design of the equipment and the operational procedure must be modified to fit the needs of the individual operation. The operation can be adjusted to include the recovery of propane, butane, pentane. 

Gasoline vapor recovery systems at large terminals... 

The surface of carbon is essentially nonpolar although a slight polarity may arise from surface oxidation. As a result, carbon adsorbents tend to be hydrophobic and organophilic. They are therefore widely used for the adsorption of organics in decolorizing sugar, water purification, and. solvent recovery systems as well as for the adsorption of gasoline vapors in automobiles and as... 

Figure 21 Flow schemalic of a gasoline vapor recovery system, using a combination of absorption and membrane separation to recover 98 + % of the hydrocarbons in the vent gas, followed by a molecular sieve pressure swing absorption (PSA) unit to remove the final 1 -2% hydrocarbon.

GKSS s licensees have installed about 30 gasoline vapor recovery systems at fuel transfer terminals, mostly in Europe. The alternative technology is to use some sort of thermal oxidizer, and this approach seems to be the most widely used technology, especially in the United States. 

The cracked products pass out through two stages of cyclones which collect entrained catalyst and return it to the dense bed. Velocities at the outlet of the dense bed are normally 2.0-3.0 ft./sec. Upon leaving the cyclones, the vapors go to the primary fractionator which separates the heavy products from the gasoline and lighter components. The light products go on to the light ends recovery unit. The heavy material is separated and either recycled to the reactor or withdrawn from the system. 

The dual-pump system is used when a large amount of gasoline is to be recovered. Separate gasoline and water pumps are used. The dual-pump system significantly reduces the amount of water that must be treated. Water pumps are placed at a depth lower than the water table to be able to establish a cone of depression, and the gasoline pumps draw out the gasoline that floats into the depression on the top of distorted water table for product recovery (Figure 18.6b). 

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