Preparation Of Activated Carbon Fiber Filter Material And Its Properties

With the wide application of organic chemical products in industry and life,high concentrations of volatile organic gases(VOCs)in the atmosphere are harmful to human health.The adsorption method is the most widely used VOCs purification method because of the simple process equipment and no secondary pollution.Adsorbents is the key to adsorption technology,among which activated carbon fiber is the most concerned as an efficient adsorption material.However,due to technical limitations,the price of activated carbon fiber is high,and most of them are made of felt-type adsorbent by non-woven needle-punching method.Such adsorbent has large filtration resistance and seriously restricts the application of activated carbon fiber filter material.This paper mainly aims to reduce the production cost and increase the adsorption capacity to prepare the high-performance activated carbon fiber structural filter materials.Firstly,this paper studies the forming method of activated carbon fiber filter material.Using viscose-based activated carbon fiber as raw material,a three dimensional microfiber structured filter was prepared by wet forming process,and compared with traditional activated carbon fiber felt.It is showed that the microfiberous structured filter material made by wet forming process with more significant three-dimensional network structure and bigger voidage,extended 2.8 times breakthrough time of benzene series organic vapor,and showed greater adsorption capacity,high permeability and better adsorption properties.Then,the effects of activation temperature,activation time and activation heating rate on the specific surface area and yield of activated carbon fiber were explored when direct activation of carbon dioxide was used to prepare high-performance activated carbon fiber.The microstructure,specific surface area,pore size distribution and surface groups of activated carbon fiber were studied by scanning electron microscopy(SEM),automatic adsorption spectrometer,infrared spectroscopy(FT-IR)and X-ray photoelectron spectroscopy(XPS).The effects of activation temperature and activation time on the adsorption properties of PAN-based filter,the differences between the adsorption properties of PAN-based and viscose-based filter and the regeneration ability of activated carbon fibers were investigated by using self-built VOCs adsorption devices.The results showed that the PAN-based activated carbon fibers with the activation temperature of 1000?,the activation time of 100 min and the heating rate of 15?/min had a maximum specific surface area of 1612 m2/g,a total pore volume of 0.73 cm3/g,and a pore diameter of 0.90 nm,rich in microporous structure,surface groups are mainly hydroxyl,amine,carbonyl,carboxyl and ester group,the ability to adsorb benzene gas strongest,of which benzene adsorption capacity of 370 mg/g,toluene adsorption capacity of 458 mg/g;compared with viscose-based filter,PAN-based filter is more suitable for adsorbing benzene gas,in which the adsorption capacity of toluene expanded by 18%;and after 5 cycles of the filter,the adsorption capacity can still maintain above 95%.The activated carbon fiber has good regeneration ability and can be recycled,which greatly reduces the production cost,effectively avoids the waste of resources and has a good prospect of engineering applications.