Experimental Research On TiO₂/ACF Photocatalytic Oxidation Of Indoor VOCs

Indoor air pollutants VOCs in many(volatile organic compounds)category,formaldehyde gas is one of the familiar mass of VOCs gas species.Residence time is long,pollution of formaldehyde in the indoor range,for the people who work in the indoor for a long time,it will cause certain harm to their health.Therefore,study of gas purification in the removal of indoor air pollution is meaningful,in this simulation is formaldehyde pollution gases in use in the test.Recently in the study of air purification,titanium dioxide(TiO2)and activated carbon fiber(ACF)composite photocatalytic oxidation pollution gas direction was much attention.Among them,the concentration efficiency of purification treatment of indoor formaldehyde in the bedroom is not very high,this is because most of formaldehyde in the indoor is in a state of free,decentralised,gaseous formaldehyde free to mass transfer resistance on the surface of the photocatalyst is larger,the mass transfer rate is not high also.So,want to improve the efficiency of the photocatalyst degradation of formaldehyde,need to find new mode to degradation,such as modified light catalyst,catalyst under different environment light on the differences in degradation of formaldehyde,etc.,so as to find out the effective pattern of the photocatalytic degradation of formaldehyde.This experimental study by homemade activated carbon fiber and titanium dioxide composite photocatalytic materials,put up closed cycle for degradation of formaldehyde test cabin.At the same time,through the change of different reaction conditions(initial concentration of formaldehyde,environment humidity,gas flow velocity,etc.),understand in a closed cycle test system,the initial reaction of formaldehyde concentration,the temperature and humidity of the test apparatus,gas flow velocity and gas residence time in device,and the effects of factors on degradation of formaldehyde.Also borrowed from the X-ray diffraction(XRD),scanning electron microscope(SEM),the chemical characterization methods such as specific surface area(BET),to recognize the homemade titanium dioxide and activated carbon fiber composite catalytic materials microstructure.In the process of degradation of formaldehyde test also adjust the placement of the uv lamp.Degradation of formaldehyde trial uv lamp as light source,placed in photocatalytic degradation of formaldehyde gas processing period in central location,activated carbon fiber as the carrier of catalyst,light also put it in the photocatalytic degradation process of parts.Found in the early formaldehyde degradation test whether light evenly placed on the degradation rate of formaldehyde is influential,near the light source the light catalytic complex can absorb ultraviolet light energy,more and more remote to accept less than enough light energy even to zero,which can not use the light catalyst,therefore,made the following adjustment,change the location of the photocatalytic process Duan Guangyuan,with power,with the wavelength of ultraviolet lamp equidistant horizontal in the degradation process period.In closed cabin also joined the centrifugal ventilator,the purpose is to provide different airflow speed test process.In addition in the experiment,using the portable gas speed detector,the goal is to enter the degradation process of the section inlet velocity were determined,the analysis results show that the gas in the whole section can be at a constant speed distributed evenly into the purification degradation treatment period.In conclusion,through many times to improve the placement of the instruments in the test apparatus,make the homemade composite photocatalytic materials by uniform illumination,gas into the degradation process of sectional velocity distribution even,make the photocatalyst can be fully used in the experimental study.To formaldehyde gas in closed cycle space capsule for the experiment of photocatalytic degradation,is to put the titanium dioxide catalyst load to the surface of activated carbon fiber,but easy reunion powders on the dispersion of titanium dioxide,and on the carrier surface adhesion ability is poorer,difficult to uniform load on the activated carbon fiber,the light catalytic degradation of formaldehyde,titanium dioxide is easy to fall off and affect the catalytic degradation of the application.Based on the above reasons,in homemade composite photocatalytic materials when choose the method of adding inorganic binder,so that the titanium dioxide better solid on activated carbon fiber body,moreover inorganic binder in use process will not be titanium dioxide degradation by ultraviolet irradiation pulverization.Using self-assembly of closed cycle and homemade cabin of composite photocatalytic degradation of formaldehyde and purification of the experimental analysis results show that the degradation of formaldehyde purification efficiency under different conditions can achieve 74% above,but if there is a new gas in the process of degradation of purification of organic intermediate,is uncertain.In addition,formaldehyde degradation experiment was carried out in the space cabin is in a certain period of time steady flow fluid dynamic circumstances.This experimental study based on titanium dioxide photocatalysis oxidation degradation of the study of the theory of the purify indoor VOCs,simulated pollutants is formaldehyde,structures,experimental closed cycle space capsule,the activated carbon fiber adsorption characteristics,as the carrier of titanium dioxide,at the same time,the preparation of titanium dioxide and activated carbon fiber composite photocatalytic oxidation,the condition of different environmental factors in formaldehyde gas,its widespread use indoor pollutants degradation photocatalyst offers help,provide people with a healthy home office environment has made a contribution.