Abatement of gaseous volatile organic compounds: A process perspective

Abstract

Abstract Volatile organic compounds (VOCs) are a class of liquid compounds with low saturation vapor pressures, which enables them to change phases even at ambient conditions. This causes a huge problem when it comes to emissions. A large portion of VOCs cause catastrophic health effects such as cancer or liver damage even at very low concentrations (ppm), and the control of these compounds is vital in ensuring good air quality. Many VOCs are used in common household implements such as wood finishes or paints and can even be emitted off improperly ventilated cooking. This significantly alters indoor air quality, and as such, a large portion of research into these compounds have focused on indoor air. On the other hand, their widespread use as solvents in most industries along with their emission rates from vehicular exhausts results in contamination of outdoor air as well. The combination of these VOCs and NOx pollutants tends to cause ground level ozone formation, which has a large bio-toxicity and causes the formation of a smog. Densely populated cities have also seen a sharp rise in VOC emissions due to the increase in both vehicular traffic and industrialization. A myriad of options is available for the abatement of VOCs, and they are similar to other pollution control strategies. These methods can be broadly be classified into destruction, separation and hybrid methods. This review discusses the different perspectives to be considered for this scenario, along with descriptions of the different methods available to the industry, along with some novel technologies that have been introduced recently. The influential parameters for each method have been investigated, along with optimum catalyst/material selection. In addition to this, a mathematical modeling perspective has also been examined, with significance to simulation studies performed for the control of VOC emission technologies.