Study On The Carrier And The New Catalyst To Remove Kitchen Cooking Oil Fume

We use catalysts in removing the kitchen cooking fumes before it came into the atmosphere.During this process,we try to reduce the volatile organic compounds(VOCs),the particulate matter(PM)and other pollutants.It is a very useful gas purification method.The current techniques are divided into physical and chemical.The physical methods are mainly by mechanical separation,filtration,absorption,washing and electrostatic law.The chemical methods commonly use thermal oxidation and catalytic combustion.We commonly use a catalyst for platinum,palladium and rhodium combination.By use of such precious metals as the main catalyst components,we can purify the volatile organic compounds(VOCs)and the particulate matter(PM),and other pollutants at the same time.However, precious metals are expensive,their resources are very limited,for these reasons,the use of precious metal as catalyst is not realistic.China is rich in Rare Earth,the reserves of rare earth are the first in the world.It has greater potential that Rare Earth may reduce the precious metal catalyst or even completely replace the precious metal in such areas.Our experimental group aimed at developing a kin of new catalyst for kitchen fume processor.In preparation of diatomite carrier,we used diatomite as the main raw material,then added wood chips and high-temperature adhesive.We did such tests as the X-ray diffraction(XRD),porosity and density,scanning electron microscopy(SEM)and EDAX Spectrum analysis to get the character of diatomite carrier including hole density,density and crystalline phase.The results showed that the porosity of structure relates to the sintering temperature.In 950℃,quartz has not yet begun the real sintering,the non-stereotyped SiO2 changes to quartz.In 1050℃and 1100℃quartz particles begin to sintering and begin the phase transition to quartz.In 950℃diatomite particles are many tubes.and there are distributed small holes in the tube wall.But in 1050℃and 1100℃,it is difficult to find and we see the overall network.In this paper,we also selected nickel-chromium alloy as a carrier,and did pretreatments of sandblasting,acid washing and water washing.In order to increase the surface area,we use the sol-gel method,we coated it with a layer of glass coating,and then coating the catalyst on it.We compared this method to the method of diatomite,both of them can remove more than 90 percent of the fume.But diatomite costs more little,the preparation is more simple,so it has more practical value.Finally,the simulation system was used to test the catalyst,we added benzene instead of fumes,the test results showed that the benzene ignition temperature was below 200℃.in the low-temperature zone(0-200℃),the purification of benzene increased significantly with higher temperature.In high-temperature zone(200-500℃),with temperature rise,the rate of benzene purification increased very slowly and close to 100%.We can come into conclusion that,catalyst in heated condition has good effect.The results showed that the comprehensive utilization of catalyst can effectively remove fumes from the kitchen of volatile organic compounds (VOCs)with more than 90 percent.Metal carrier is expensive,and the preparation of catalyst coating is complex.On the other hand,the diatomite supported catalyst is prior in porosity,the number of holes,simple preparation,broad source of raw materials and low prices.So it has very good value and good prospect.