Analysis of VOCs Efficient Treatment Technology

VOCs (Volatile Organic Compounds, volatile organic compounds) are one of the common pollutants emitted by petrochemical, pharmaceutical, printing, painting and other industrial production processes and motor vehicles. With the development of industry, the amount of VOCs # is increasing day by day, and it has the characteristics of wide range and large emission. Its governance has become one of the hot spots in the current international environment, and relevant environmental legislation is becoming more and more strict. VOCs are a class of hydrophobic and persistent organic pollutants, which are easy to accumulate in fatty-rich tissues, and most of them are carcinogenic, teratogenic, mutagenic, and potentially harmful to the environment. Many VOCs have been listed by the US National Environmental Protection Agency. For priority control and priority monitoring of pollutants, such as halogenated alkanes, chloroalkenes, chloroaromatics, aromatics and their oxidation products and nitrogenation products. In the production process of the petrochemical industry, organic waste gas pollution containing foul odor often occurs, which seriously endangers people's health. The volatile organic waste gas discharged into the atmosphere by the petrochemical industry includes benzene series, aldehydes and ketones, halogenated hydrocarbons, alcohols, etc. The treatment technology of organic waste gas can be roughly divided into two categories: one is recovery, which is suitable for the treatment of high-concentration organic waste gas. The commonly used measures are: adsorption, condensation and absorption; the other is destruction, commonly used are combustion and biological purification. and catalytic oxidation. In the recovery and treatment technology of organic waste gas, the absorption method requires large energy consumption to regenerate the absorption liquid in most cases, otherwise it will cause secondary pollution. The condensation method is only suitable for the pretreatment of high-concentration organic waste gas, but it is expensive to reduce the concentration of harmful substances to a lower level. The adsorption method also has the problem of regeneration of the adsorbent, and the industrial adsorption method is only economically feasible when it is used in combination with other technologies. The membrane separation method requires a pressure difference as a driving force. If there is no pressure difference in the process before and after the separation operation, it also requires a large energy consumption to complete the operation. In the destruction and treatment technology of organic waste gas, the application of biological method is limited due to its large area. Due to the limitation of biological species, there are many kinds of organic substances that can be treated by non-biological methods. In addition, due to the short research time, its mechanism, technology and Engineering and many other aspects remain to be further explored. Plasma catalytic oxidation, microwave catalytic oxidation and photocatalytic oxidation are still in the laboratory research stage, and there are still many problems, such as the operation stability of electron accelerators, which are difficult to solve now, and there is still a relatively long distance from industrial application. At present, the combustion method that has been practically used in the industry is expensive to operate, and it is easy to produce secondary pollutants if the process conditions are improperly controlled. If the temperature is too low, the combustion will not completely produce dioxins. When the temperature is too high, NOx will be produced. Organic waste gas. Catalytic combustion is an oxidation reaction that occurs under the action of a catalyst, which can oxidatively decompose harmful and combustible components in exhaust gas at lower temperatures. Compared with other treatment methods, catalytic combustion method is more efficient and energy-saving, reduces secondary pollution, and is an effective method for removing organic waste gas. The purpose of the present invention is to propose a high-efficiency treatment method for VOCs in view of the deficiencies of the existing waste gas treatment technology. For this purpose, the present invention adopts the following technical scheme: [0010] a kind of efficient treatment method of VOCs, described method utilizes catalytic oxidation and adsorption process in conjunction with processing petrochemical industry organic waste gas, described method comprises the following steps: (1) adopt cloth bag The precipitator pretreats the petrochemical industry organic waste gas, reclaims some materials, and then introduces an electrostatic precipitator to carry out electrostatic dust removal, and further recycles materials; (2) the waste gas treated in step (1) is subjected to catalytic oxidation treatment; (3) the step (2) The treated exhaust gas is discharged after adsorption treatment. In the invention, the waste gas is first dedusted by a bag filter and an electrostatic precipitator to recover materials; the dedusted waste gas is subjected to low-temperature catalytic oxidation treatment to eliminate the smell of organic waste gas, and finally discharged through adsorption treatment. the present invention“efficient”It means that the final flue gas emission concentration of the petrochemical industry organic waste gas treated by the treatment method is more than 30% lower than the emission standard. In the drying treatment process of petrochemical products, most of the products remain, and a small part of products are discharged by the blower together with the exhaust gas in the form of white powder. The present invention reclaims the material in the exhaust gas discharged by the blower by step (1). Some items are part of the product. The bag filter described in the step (1) is arranged at the petrochemical product drying tail gas place. Since the tail gas after the drying treatment of petrochemical products contains white powder materials, the materials are recovered and the organic waste gas is treated by the method of the present invention. Appropriate catalyst active components can reduce the energy barrier of the reaction and promote the generation of free radicals, so that the catalytic oxidation of VOCs can be carried out at a lower temperature and reduce the energy consumption required for the treatment. In addition, a suitable catalyst support can more effectively capture VOCs molecules in the gas phase host, and provide more active sites per unit specific surface area to promote the reaction. The catalyst used in the catalytic oxidation treatment in step (2) is a noble metal catalyst, a transition metal oxide catalyst or a composite oxide catalyst, preferably a Pt catalyst. The Pt catalyst has the advantages of high catalytic activity, good selectivity, erosion resistance and long service life. Preferably, a temperature control system is provided near the surface of the catalyst. An ozone generator, preferably an ultraviolet type ozone generator, is arranged above the catalyst.