Abstract
A new paraffin/surfactant/water emulsion (PSW) for volatile organic compounds (VOCs) controlling was prepared and its potential for VOCs removal was investigated. Results indicated that PSW-5 (5%, v/v) provided higher toluene absorption efficiency (90.77%) than the other absorbents used. The saturation pressure, Henry’s constant, and activity coefficient of toluene in PSW-5 were significantly lower than those in water, and toluene solubility (1.331 g·L−1) in the PSW-5 was more than 2.5 times higher than the value in water. Several factors potentially affecting the toluene absorption efficiency were systematically investigated. The results suggested that concentration and pH of PSW, absorption temperature, and gas flow rate all had a strong influence on the toluene absorption, but the inlet concentration of toluene had little effect on the toluene absorption. There were different absorbing performances of PSW-5 on different VOCs, and the ketones, esters, and aromatics were more easily removed by the PSW-5 than the alkanes. Regeneration and reuse of the PSW were possible; after 3 runs of regeneration the absorption efficiency of PSW-5 for toluene also could reach 82.42%. So, the PSW is an economic, efficient, and safe absorbent and has a great prospect in organic waste gas treatment.
Highlights
In recent years, volatile organic compounds (VOCs), due to their high volatility, reactivity, and toxicity to humans and environment, have received increasing attention as the air pollutants of serious concern [1]
It can be seen that the toluene absorption efficiencies of six kinds of absorbents all decreased by time due to the gradual saturation of absorbents
(1) For different types of organic matter, the absorption efficiency generally increases with the increase of the molecular polarity and the decrease of logarithm of the octanol/water partition coefficient of VOCs. (2) For the same type of hydrophobic VOCs, such as benzene series, the larger saturated vapor pressure of VOCs, the lower absorption efficiency achieved, and the absorption efficiency generally increases with the increase of logarithm of the octanol/water partition coefficient of VOCs. (3) The absorption efficiencies of hydrophilic VOCs are better than that of hydrophobic VOCs. (4) Most hydrophobic and hydrophilic VOCs can be effectively removed by paraffin/surfactant/water emulsion (PSW)
Summary
Volatile organic compounds (VOCs), due to their high volatility, reactivity, and toxicity to humans and environment, have received increasing attention as the air pollutants of serious concern [1]. In order to meet the stringent environment regulations, VOCs emission from industry must be effectively controlled. Various technologies have been developed to remove VOCs from exhaust gas and basically classified into two groups based on recovery and destruction [5]. Most of VOCs from industry exhaust gas are hydrophobic, which correspond to low solubility in water, but high solubility in high-boiling organic absorbents. In order to overcome the disadvantages of organic absorbent, emulsions such as surfactant/water [26] and water/oil emulsions [2] have been developed They have low viscosity and high security and can remove VOCs efficiently. Paraffin was used to prepare emulsion, due to its high absorption capacity of VOCs, high stability, low cost (about 900 $⋅ton−1 in China), degradability, and no toxicity. The solubility, saturation pressure, Henry’s constant, and activity coefficient of toluene in the emulsion were calculated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
