VOC Recovery Via Membrane Separation

VOCs (Volatile Organic Compounds) include dozens of gaseous pollutants. Their sources are very wide, and they do much harm to the health of humanbeing, besides, they are dangers to factories producing them or using them. With economy developing, the volumes of VOCs discharged are bigger and bigger, therefore, they become the key objects of gasesous pollutants controlling. Membrane technique which developed in 20^th century is a novel separation technique. Applying Membrane technique in the separation of VOCs not only could control the pollution of VOCs, but also could recover VOCs which are of great value in industry. This satisfies the requirement of instructing economic society.This papar applies a novel silicone membrane Polyoctylmethylsiloxane (POMS) in the field of VOCs separation and recovery for the first time. Experiments in this paper investigated the POMS's separation efficiency of common VOCs, Toluene and Ethal acetate, compared the results under different operating conditions and analyzed the influence of permeate pressure difference, feed condentration, feed volumes and the thickness of POMS on the separation efficiency, which supplied valuable data for the industrial application of POMS. Besides, experiments in this paper also tested and compared the solubility of toluene, ethyl acetate, dimethylbenzene, acetone and n-butanol, and forcasted the separation efficiecy of them using POMS membrane.The separation experiments were all operated under vacuum pressure ≦0.1MPa, and the separation effiency of toluene and ethyl acetate are quite good: when feed capacity is1.78m³/(m² ? h), the removal of tolunen and ethyl acetate could reached nearly 90% using spiral wound membrane. When pressure difference is 0.08MPa with spiral wound membrane, the toluene permeance could reach 8.01E-07 mol/(s ? m² ? Pa), and ethyl acetate 8.12E-07 mol/(s ? m² ? Pa); Among all operating parameter, permeate pressure difference influnces the separation efficiency most, the higher permeate pressure using, the highter separation efficiency could reach; VOCs'removal becomes smaller with the feed flow augmenting, however, when feed volume ranges between 1.78m³/( m²Â·h)-2.81m³/( m²Â·h) , the VOCs's permeance don't change much, being a stable value, which could be used in the design of membrane separation process; The feed concentration and the thickness of POMS don't influent much on the separation efficacy of VOCs, experiments of feed concentrion range...