Research On Control Of VOCs In Condensation Zone Coking Plant

The volatile organic compounds (VOCs) were released in various industry activitieswith complicated compositions. Recently， the serious influence of VOCs to the humanhealth and the environment were recognized gradually, and there are more attentions tothe disposal of VOCs. Volatile organic gases mainly include toluene, xylene, phenol andnaphthalene in Condensation Zone Coking Plant. The treatment methods of VOCs areincluding adsorption, membrane condensation, biochemical method and combustion etc.The adsorption has been suggested as the most common treatment technology toVOCs. Many studies have shown that activated carbon (AC) is the best adsorbent used toadsorption of VOCs. The study mainly investigated the influences of AC types, thethickness of adsorption bed, temperature, the gas concentrations of the entrance, gas flowrate on adsorption efficiency. The main results are summarized as follows:(1) theadsorption capacity of AC positively correlated with the specific surface area and porosity.(2) The change of thickness of adsorption bed did not affect the shape of adsorptioncurves, however caused the adsorption curve left-right shifts.(3) The higher the inputconcentration and superficial velocity, the lager the breakthrough curve slope in center ofthe MTZ (Mass Transfer Zone), and the easier to reach saturated extent of adsorption.(4)Compared with higher temperature, the adsorption capacity under lower temperature islarger, the operation is more simple and convenient. Consequently, the study determinedthat adsorption is under normal temperature. Desorption is the reverse process ofadsorption, and usually occurred under high temperature or low pressure. The studydiscussed the desorption efficiencies of the100℃,150℃,200℃under ordinarypressure, drew a conclusion that high temperature is beneficial to desorption, but overhigh lead to increasing of operating cost. So, the research determined the desorptiontemperature as200℃, desorptiontime as120min.