1、,Air Pollution Control Engineering,Lecture 10 Control of Volatile Organic Compounds (VOCs),Particulate pollutantsVolatile Organic Compounds (VOCs)(the second-most widespread and diverse)Sulfur OxidesNitrogen Oxides,The four major air pollutants,Lecture 10 Control of Volatile Organic Compounds (VOCs)
2、, VOCs and Vapor Pressure Control by Prevention Control by Concentration and Recovery Control by Oxidation Summary, VOCs and Vapor Pressure,VOCs are those organic liquids or solid whose room temperature vapor pressures are greater than about 0.01psia (=0.0007atm), and whose atmospheric boiling point
3、 are up to about 500 (=260), which means most organic compounds with less than about 12 carbon atoms.,Page 336,Definition, VOCs and Vapor Pressure,Vapor pressure,Liquid, xi,gas, yi, pi,p,Raoults law,Page 333, VOCs and Vapor Pressure,Vapor pressure,Liquid, xi,gas, yi, pi,p,Page 333,yi, VOCs and Vapor
4、 Pressure,Examples,Hydrocarbon(HC),Acetone, CH3-CO-CH3,Mercury,Methyl chloride, CH3Cl, Control by Prevention,(1) substitution,(2) Process modification,(3) Leakage control,Breathing losses, Control by Prevention,Breathing losses,Tanks containing liquid VOCs can emit VOC vapors because of filling and
5、emptying activities as well as changes in temperature and atmospheric pressure. These emissions are called filling or displacement losses, emptying losses, and breathing losses, working losses,Page 338, Control by Prevention,Vapor,Liquid, Control by Prevention,Floating roof tank,Page 345, Fig. 10.4,
6、 Control by Prevention,Underground storage tank having a vapor return system,Page 345, Fig. 10.5, Control by Prevention,Page 347, Fig. 10.6,Underground storage tank to a users vehicle using a vapor return system, Control by Concentration and Recovery,(1) Condensation (冷凝法),(2) Adsorption (固体吸附法),(3)
7、 Absorption (液体吸收法), Control by Concentration and Recovery,(1) condensation,One can remove most of the VOCs from an air or gas stream by cooling the stream to a low enough temperature that most of the VOCs are condensed as a liquid and then separated from the gas stream by gravity.,Page 350, Control
8、 by Concentration and Recovery,Page 351, Fig. 10.8, Control by Concentration and Recovery,(2) Adsorption,Adsorbent bed,Page 354, Control by Concentration and Recovery,(2) Adsorption,Page 355, Fig. 10.10,Adsorbent bed,Cleaned Air with few VOCs,# 1,# 2,# 3,Condenser,Cooling water,separator,乐凯胶片集团公司二氯甲
9、烷尾气吸附回收装置,活性炭纤维有机废气吸附回收装置,齐鲁石化储运厂石脑油回收装置,活性炭纤维有机废气吸附回收装置,南通农药厂混苯回收装置,活性炭纤维有机废气吸附回收装置, Control by Concentration and Recovery,(3) Absorption (scrubbing),If we can find a liquid solvent in which the VOC is soluble and in which the remainder of the contaminated gas stream is insoluble, then we can use a
10、bsorption to remove and concentrate the VOC for recovery and re-use, or destruction., Control by Concentration and Recovery,(3) Absorption (scrubbing),Page 362, Fig. 10.15,Absorption and stripping process,备有喷淋、洗涤、吸收及中和功能,Comparison between adsorption and absorption, Control by Concentration and Reco
11、very,Adsorption,Absorption, Control by Oxidation,(1) combustion(Incineration) (焚烧法),(2) Biological Oxidation(Biofiltration) (生物氧化法), Control by Oxidation,(1) combustion(Incineration),Page 371,(1) combustion(Incineration),Combustion may cause the secondary pollution.,Hg(L),Hg(G),(1) combustion(Incine
12、ration),(a) Simple thermal incinerator,(b) Thermal incinerator with regenerative heat recovery,(c) Catalytic incinerator,Page 376, Fig. 10.17,一般催化燃烧流程,废气入口,热交换器,预热室,催化床,排气,补充能量,有机废气的种类,烷烃类、苯及苯系物、醇类、酚类、酮类、醛类、酯类、胺类、腈、氰、金属有机物、非金属有机物等。,有机废气净化装置应用范围,汽车制造业、自行车、摩托车、家用电器、电线电缆、漆包线、电机及电机绝缘处、电器、仪表、电子、石油化工、涂料、化
13、工、印铁、印刷、家具、皮革、鞋业、玻璃、建材等行业。, Summary,Choosing a control technology according to the different concentration.,Page 382, Fig. 10.19,This Lecture and the Next Lecture,This Lecture: Chapter 10 page 329382,The Next Lecture: Chapter 11 page 395430,Exerciser,Please comparing the Adsorption with absorption for VOCs control.,DISCUSSION,Topics about Air pollution: Introducing yourself Interesting news or information about air pollution your having read or heard Your opinions on this Air Pollution course Your suggestions for Chinese Air Pollution Other familiar issues about Air Pollution,
