Novel Polymer Resin For Adsorption Of Low Concentration Organic Waste Gas

The pollution of Volatile Organic Compounds(VOCs)is a serious environmental problem.The adsorption is a widely used technique in the industry to eliminate VOCs for its operation simply,low cost,high efficiency.Activated carbon is the widely used adsorbent at present,but its development has been limited by some drawbacks such as fire risk,pore clogging,hygroscopicity and a lack of regenerative ability.Therefore,there is an urgent call for polymer resin with a considerable adsorption capacity,hydrophobicity and stability to replace the active carbon.The effect of adsorption conditions such as VOCs,concentration,different humidity on adsorption ability were investigated over the commercial macroporous adsorption resins X-5,AB-8,D101,D1400,XAD-2 resin.The results showed that macroporous adsorption resins have better adsorption performance for these VOCs with higher boiling point and bigger molecular diameter.The resins with high specific surface area,large entrance,small pore diameter is more suitable to the adsorption of organics.The adsorption is mostly not effected by water vapor because of its high hydrophobicity of resin.The VOCs on resins can be desorbed mostly at 60?.However,macroporous adsorption resins are not competitive in adsorption of low concentration VOCs comparing with activated carbon.Therefore,polymer resins with higher specific surface area and smaller pore size is necessary for low concentration.Two kinds of polymer resin StD-1 and PDVB with micropores and high surface area were prepared.The adsorption equilibria of dichloromethane and ethanol vapor onto StD-1 resin were investigated by the danymic adsorption method at the temperature of 303K,318K and 333K.The adsorption equilibria of toluene on PDVB at the above temperatures were also investigated.The results showed that:?StD-1 and PDVB resins have excellent adsorption characteristic under the conditions of low-temperature and higher-pressure.The experimental data could well be fitted by Dubinin-Astakov equation in the experimental temperature range.?The qv-? equation could predict the adsorption isotherm of another temperature according to the adsorption isotherm of a given temperature.?The isosteric heats of adsorption from Clansius-Clapeyron equation show that the isosteric heats of StD-1 resin are lower than that of activated carbon.?The Yoon-Nelson model is good to fit the breakthrough curves of StD-1 and PDVB resins,and the model parameters obtained from the experimental data not only could describe the adsorption process but also predict the breakthrough curves correctly.For the weakness of bigger pore diameter and poor skeleton structure of MCM-41,while PDVB resin has unique pore structure,large specific surface area and good adsorption performance,divinylbenzene(DVB)monomer was adsorbed into the pore of MCM-41 and then reacted under solvothermal condition.As a result,the novel PDVB@MCM-41 adsorbent was prepared by polymerization which made this organic-inorganic material has small pore diameter and high hydrothermal stability.The adsorption performance of low concentration toluene on PDVB@MCM-41 and the hydrothermal stability of PDVB@MCM-41 were investigated.Comparing with pure MCM-41,the average pore diameter shrinks from 2.4nm of MCM-41 to 2.0nm of PDVB@MCM-41,and the wall thickness of pores increases from 1.1924nm to1.6763nm.The adsorption capacity of 1000mg/m3 toluene on PDVB@MCM-41 is raised by 2.2 times higher than that on MCM-41.PDVB@MCM-41 still has mesoporous structure after hydrothermal treatment for 10h,which indicated that PDVB@MCM-41 has high hydrothermal stability.PDVB@MCM-41 can be efficiently regenerated at the temperature of 80?.Therefore,PDVB@MCM-41 has great desorption performance.