Study On Adsorption Improvement Of Low Concentrations Toluene On Active Carbon

With the enhancement of environmental awareness and extension of clean production, the industry waste gas shows gradually the characteristic of low concentration and high air volume, and indoor VOCs under very low concentration can be harm to people's lives and properties. The adsorption of VOCs with active car bon is classical technique. Based on above aspects, this paper adopts the methods of inducing Ozone, impregnating modification and so on to improve adsorption of low concentration VOCs on active carbon, and research the enhancement effect of used measurements.This paper chooses Toluene as the VOCs representation, and adopts three materials, namely fresh origin active carbon, ozone modification active carbon and impregnating modification carbon, to study the toluene adsorption experiment on low concentration toluene and mixture gas of toluene and zone. This paper also discusses the effect of zone in this system, and preliminary attempt to study the effect of inducing mist. The main results are showed in followings:The inlet concentration of toluene and ozone is about 33mg/m³ and 550mg/m³ respectively, and air flow velocity is 0.68m/s. Compared with the breakthrough of active carbon with toluene alone, the settled concentration breakthrough time of toluene penetration through ozonation origin active carbon and co-penetration through origin active carbon with ozone is prolonged by 8.9% and 22.7% respectively. The protection effect time is prolonged respectively and the adsorption capacity is also increased to a certain extent. The protection effect time prolonging of toluene penetration through origin active carbon is due to enlarging of specific surface area and porosity of origin active carbon by Ozone during penetration through origin active carbon, while the protection time prolonging of co-penetration through origin active carbon with ozone is the result of the modification of interior structure of active carbon and parts of the toluene is oxidized by middle product of the reaction between carbon and ozone. Using Mn(Ac)₂, Cu(Ac)₂, Mn(NO₃)₂, Cu(NO₃)₂ solution to impregnate origin active carbon, and under different temperatures roast and dry, then man can obtain modification active carbon, and sets blank active carbon as reference. The inlet concentration of toluene and ozone is about 33mg/m³ and 550mg/m³ respectively, and air flow velocity is 0.68m/s. The toluene and ozone adsorption testing of impregnated modification active carbon has showed that the support state of metal oxide on active carbon surface under 300°C drying and roasting condition is better than any other conditions. The adsorption capacity of active carbon impregnated by acetate for toluene is better than one impregnated by nitrate, the adsorption/remove capability of active carbon impregnated by manganese salts for ozone is better than one impregnated by cupric salts. Take the active carbon impregnated by Mn(AC)2 under 300°C drying as an example, compared with blank active carbon, the protection time of toluene penetration through this active carbon alone and co-penetration through this active carbon with zone is prolonged by 7.0%,29.0%, the protection time of toluene penetration through ozonation active carbon remains basically unchanged, the protection time of co-penetration through this modification active carbon with ozone is reduced by 14.4% when inducing mist.