The Assessment on the Efficiency of Vapor Recovery System in Gas Station
| Autor: | Yu-Tsung Cheng, 鄭育宗 |
|---|---|
| Rok vydání: | 2006 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 94 This research mainly investigates the improvement of vapor recovery efficiency by adding a VACONOVENT membrane-adsorption vapor recovery system to the traditional vacumm type system. The membrane-adsorption system can collect the excessive gasoline vapor in the fuel tank and recycle back into liquid gasoline. Such system can achieve A/L values up to 1.5. Therefore the membrane-adsorption system not only effectively reduces the vapor discharge but also improves the vapor discharge problem. In order to evaluate the recovery efficiency, an experiment was conducted to measure the concentrations of VOCs at various locations in a gasoline station and the A/L values under the conditions with and without the VACONOVENT membrane-adsorption system. The purpose of these measurements is to understand the VOCs pollution problems during the refueling process. The gasoline vapors are not only effectively recycled and the adsorbed vapors are stored in the membrane. Because the volatile macromolecules are absorbed by the membrane unit and then followed by the desorption process in the membrane pot. The percentages of desorption can reach to 99%. The adsorbed vapors are decomposed to hydrocarbon and air and then flow back to the fuel tank as the liquid gasoline. Only the clean air is allowed to be discharged so that the VOCs pollution is reduced. In the actual test of the A/L recovery efficiencies, the recovery efficiency is 1: 1 for the traditional vacuum system and 1:1.5 for the system adding the membrane-adsorption vapor recovery unit. The results show that the system with the vacuum recovery unit can reduce 75% vapor discharge and the membrane-adsorption recovery system can reduce 95% vapor discharge. The measurements were conducted at eight locations with two various heights from ground in a gas station during the heavy traffic hours and the regular hours. The experiments were performed for nine days. With the additional VACONOVENT membrane-adsorption vapor recovery system, the reduction rate of VOCs concentrations near the gasoline refilling location can reach to 45%. In conclusion, this research evaluates the improved vapor recovery efficiency by adding the VACONOVENT membrane-adsorption gasoline vapor recovery system to the traditional vacumn system. The results provide the useful data and information for improving the air pollution problem in the gas stations. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|