Preparation And Properties Of High Specific Surface Area Activated Carbon From Petroleum Coke

Activated carbon is widely used in the purification of air,sewage treatment,chemical product collection,food processing,pharmaceutical production,the preparation of catalytic materials,sup er capacitor anode material,precious metal extraction and other fields.Petroleum coke is a by-product of the oil industry,carbon content is considerable.High yield,low price,and showing a porous distribution,large surface area,low ash fraction characteristics,is considered to be the best raw material for activated carbon preparation.The development of petroleum coke activated carbon production technology to improve the quality of domestic activated carbon,change the status of high-grade activated carbon dependence on imports has become the focus of domestic research.In this paper,in order to design a optimum synthesis route of petroleum coke activated carbon,we study the seven factors including pretreatment of ingredient,kinds of activator,proportion of activator,the way of activation,the way of washing,method of drying and the particle size of petroleum coke.Based on the above research,the prepared petroleum coke-based activated carbon adsorbs heavy metal wastewater and dye wastewater,and the carbon residue after adsorption is prepared into the electrode materials for supercapacitor and fuel cell respectively,This can effectively avoid the sludge buried,burning and other secondary pollution.The morphology and structure of activated carbon were characterized by BET,SEM,XRD,XPS and EDX-Mapping.The electrochemical properties were investigated by cyclic voltammetry.The adsorption effect was investigated by simulated wastewater test.The results of the experimental study are as follows:(1)The optimum synthesis route of petroleum coke activated carbon:Petroleum coke as raw material,without any pretreatment,KOH as activator,the mass ratio of petroleum coke and activator is 3:1.The petroleum coke and activator are mixed evenly,and then put the mixture into the tube furnace with 800?to activate 1 h,after cooling to room temperature,washing by deionized water and drying in air to remove ash content.The obtain petroleum coke activated carbon with the specific surface area is 3281.4 m~2/g,The average pore size is 1.42 nm and the pore volume is 1.76 cm~3/g.(2)The performance of high specific surface area activated carbon was evaluated in an electric double layer capacitor,from the results of cyclic voltammograms of electrochemical test,when the specific surface area is 2581.4 m~2/g,the average pore size is 1.43 nm,the specific capacitance is 246.45 F/g.(3)In the waste water simulation test,the petroleum coke activated carbon is used as adsorbent.Under the conditions of adsorption temperature of 35?,initial concentration of metal ions of 12 mg/L,activated carbon input of 15 g/L,adsorption time of 5 h,the adsorption rate reaches 99%.And adsorption residue after heat treatment is named AC/MnO_X composites which can be used as electrode,and when the scanning speed is 5 mV/s,the specific capacitance is 145F/g.(4)The kinetic and thermodynamic studies of petroleum coke activated carbon as adsorbent were carried out.First,the study of activated carbon adsorbs heavy metal manganese ions in waste water shows that the adsorption process is belongs to Two Level Kinetic model and meets Freundlich thermodynamic model.Second,the study of activated carbon adsorbs MO dye in waste water shows that the adsorption process is belongs to Quasi-two Level Kinetic model and meets Langmuir thermodynamic model.(5)Based on the above research,we try to use the low temperature plasma method instead of the traditional KOH activate to synthesis banana peel activated carbon.The low temperature plasma method can avoid the disadvantage of high content activator,This treatment provides a new idea for the rational use of banana peel.Results show that the method of low temperature plasma method is simple,preparation period is short,the structure of raw materials can be kept.Besides,low temperature plasma method can increase the functional groups on the surface of the raw material to improve the electrochemical performance.The cyclic voltammograms of electrochemical test shows the specific capacitance of banana peel activated carbon is 150.81 F/g.