The Technology And Mechanism Of Preparing Activated Carbon From Petroleum Coke With Alkali

High specific surface activated carbon with developed pore structure,stable physical and chemical properties and good electrical conductivity has been widely used in the fields of gas storage and transportation,sewage treatment,supercapacitor and catalyst carrier.Using KOH to activate petroleum coke is a common method to prepare activated carbon in many preparing raw materials of high specific surface activated carbon.At present,there are many intermittent activation devices in China with the disadvantages of low production efficiency and high production cost.In order to achieve continuous production,the most difficult problem in the process of plant activation is the "sticky wall phenomenon",which is the key problem to restrict the production of the continuous production of activated carbon.In order to achieve adhesive breaking,the paper start from the "sticky wall phenomenon",and investigated the activation stage and activation mechanism of activated carbons.The experiments were carried out in a self-made rotary furnace,and the raw materials were selected Liaohua petroleum coke,and then activated carbon was prepared by one step activation under the action of KOH activator.The different initial temperature,different constant temperature time,different N2 protection gas flow rate and different intermediate temperature time were first investigated under the existing activation conditions.In the four case,the change of the specific surface area and pore structure of activated carbons were studied.The experimental results show that in terms of the experimental results,at the weight rate of KOH/PC is 3:1,the final temperature at 750?,the constant temperature time is 60 min,the N2 flow rate of the protective gas is 270ml/min,and intermediate does not stay will be better.However,as far as concerning the laboratory device,when the constant temperature more than 40 min,the yield of activated carbon will be severely reduced.Also when the N2 flow rate is increasing,it will make the device outlet blockage,which is not conducive to actual production.In addition,the formation laws of various substances in the process of appeals reaction were explored to study the reaction mechanisms in the reaction process,and to find the main source of the viscosity.The methods of infrared chromatography,Gibbs free energy calculation,quantitative analysis and XRD analysis were used in the process to investigate the reaction mechanisms and the possible reaction equation of water,hydrogen,methane,and K.Through the analysis of these equations and actual conditions,we find the main reason for the "sticky wall phenomenon" is that the petroleum cokes were wrapped with the superfluous KOH which make the mass of the mass were hard to open in the later period of reaction.Then try to solve the "sticky wall phenomenon" based on the entry of the CO2 gas.By analyzing the distribution of the particle size and the specific surface area and the distribution of the pore size,it is found that the entry of CO2 can effectively solve the "sticky wall" phenomenon”,and the pore structure can be changed on the premise of maintaining high specific surface area,which makes the micropore diameter increase step by step,and the mesopore diameter is basically unchanged.