Example of removal of organic pollutants from off gas generated from small activities in proximity of urban areas

This article describes a theoretical application aiming at the potential recovery of organic pollutants poorly soluble in water and with a molecular weight higher than that of water. The organic pollutants must be present in the gas stream to be treated only in low concentrations. A case study was considered in which chlorobenzene was taken as organic pollutant of reference. The application can be interesting when applied to industrial off-gases, especially if generated in proximity of urban areas. Indeed, often in most industrialized regions of northern Italy the urban/industrial planning has not adequately separated the residential and productive areas: the presence of a number of small polluting activities can create critical conditions of human exposure even in absence of large emitters. The system is developed according to two alternative process schemes (liquid -liquid separator equipped with a coalescer and separation using membrane process). The goal is twofold: from an environmental point of view, the aim is to treat the gas flow, limiting the dispersion into the atmosphere of hazardous pollutants; to this, an economic target should be added, with the opportunity to simultaneously retrieve reusable substances in industrial production cycles.