Analysis of VOCs Efficient Processing Technology

VOCs (Volatile Organic Compounds) are one of the common pollutants emitted by industrial production processes and motor vehicles in petrochemical, pharmaceutical, printing, painting and other industries. With the development of industry, the volume 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 of the current international environment, and the relevant environmental legislation has become increasingly strict. VOCs are a type of hydrophobic and persistent organic pollutants, which are easy to accumulate in fatty tissues, and most of them are carcinogenic, teratogenic, mutagenic, and potentially harmful to the environment. Many VOCs have been listed by the US Environmental Protection Agency. Pollutants for priority control and priority monitoring, such as haloalkanes, chloroalkenes, chloroaromatics, aromatics and their oxidation products and nitriding products. In the petrochemical industry, foul-smelling organic waste gas pollution often occurs during the production process, 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 recycling, which is suitable for the treatment of higher concentration organic waste gas. The commonly used measures are: adsorption, condensation and absorption, etc.; the second 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 in most cases requires a large energy consumption to regenerate the absorption liquid, 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 adsorbent regeneration. In industry, the adsorption method is mostly 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, a large energy consumption is required 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 non-biological methods that can treat organic matter. In addition, because the research time is not long, its mechanism, process Many aspects such as engineering need to be further explored. Plasma catalytic oxidation, microwave catalytic oxidation and photocatalytic oxidation are still in the laboratory research stage. There are still many problems, such as the operational stability of electron accelerators, which are difficult to solve now, and there is still a relatively long distance from industrial applications. At present, the combustion method that has been used in industry has high operating costs, improper control of process conditions is easy to produce secondary pollutants, low temperature combustion does not completely produce dioxin, and high temperature will produce NOx, etc. It is not suitable to treat lower concentrations Organic waste gas. Catalytic combustion is an oxidation reaction that occurs under the action of a catalyst, which can oxidize and decompose harmful combustible components in the exhaust gas at a relatively low temperature. Compared with other treatment methods, the catalytic combustion method is more efficient and energy-saving, reduces secondary pollution, and is an effective method to remove organic waste gas. The purpose of the present invention is to provide an efficient treatment method for VOCs in view of the shortcomings of the existing exhaust gas treatment technology. To achieve this objective, the present invention adopts the following technical solutions: [0010] A high-efficiency treatment method for VOCs, the method uses a combination of catalytic oxidation and adsorption processes to treat organic waste gas from the petrochemical industry, the method includes the following steps: (I) using cloth bags The dust collector pre-treats the organic waste gas of the petrochemical industry, recovers part of the materials, and then introduces the electrostatic precipitator for electrostatic dust removal, and further recovers the materials; (2) the waste gas after step (I) is subjected to catalytic oxidation treatment; (3) the step (2) The treated exhaust gas is discharged after adsorption treatment. The invention firstly uses a bag filter and an electrostatic precipitator to dedust the exhaust gas and recover materials; the dedusted exhaust gas undergoes low-temperature catalytic oxidation treatment to eliminate the smell of organic waste gas, and finally is discharged after adsorption treatment. The 'high efficiency' in the present invention means that the final flue gas emission concentration of the petrochemical industry organic waste gas treated by the treatment method is lower than the emission standard by more than 30%. In the drying process of petrochemical products, most of the products remain, and a small part of the products are discharged by the fan together with the exhaust gas in the form of white powder. The present invention recovers the materials in the exhaust gas discharged by the fan through step (I). Some materials are part of the product. The bag filter described in step (I) is set at the petrochemical product drying tail gas. Since the tail gas after 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. A suitable catalyst active component can lower the energy barrier of the reaction, promote the generation of free radicals, enable the catalytic oxidation of VOCs to be carried out at a lower temperature, and reduce the energy consumption required for processing. In addition, a suitable catalyst carrier can more effectively capture the VOCs molecules in the main body of the gas phase, and provide more active sites per unit specific surface area to promote the progress of the reaction.