Preparation, Monolith And Preliminary Application Of High-Surface-Area Activated Carbon

This paper introduces the research progress about the preparation, monolith and preliminary application of high-surface-area activated carbon (HSAAC) at home and abroad. Based on that, the application of HSAAC in gasoline adsorption and electric double layer capacitor is related in detail.A series of petroleum-coke activated carbons (PCACs) were prepared by using KOH as an activation agent and petroleum coke as raw material. The effect of KOH/Coke ratio, activation temperature and activation time on the yield and iodine adsorption value was investigated by orthogonal test and further single factor experiments. The results indicated that the significant factor for iodine adsorption value was KOH/Coke ratio. The iodine adsorption capacity can be improved by increasing KOH/Coke ratio,extending the activation time and selecting the appropriate activation temperature. PCAC with the yield of 55.8% and BET specific surface area of 2775 m2/g and total pore volume of 2.888 cm3/g was prepared under the conditions of KOH/Coke ratio 4:1, activation temperature 750℃and activation time 120 min.A series of black-liquor activated carbons (BLACs) were prepared by using KOH as an activation agent and black liquor of pulping process mixed coconut shell as raw material. The effect of black liquor and coconut shell mass radio, KOH/C mass ratio, activation temperature and activation time on the yield, ash content and methylene blue adsorption value was investigated by orthogonal test and further single factor experiments. The results indicated that BLAC sample with the methylene blue adsorption value of 450ml/g and BET specific surface area of 2113 m2/g and total pore volume of 0.976 cm3/g was prepared under the conditions that carbonized black liquor and coconut shell mass ratio of 2.5:1, carbonization temperature of 600℃, carbonization time of 1h; activated KOH/C mass ratio of 3.5:1, activation temperature of 900℃, activation time of 120 min.Microwave modified PCACs were researched in the application of gasoline adsorption. Two activated carbon samples which were modified by microwave and chemistry-microwave for 4 min increased the 90 gas saturation adsorption value by 9.4% and 20.7%, respectively. However, when PCACs were used in multi-gasoline adsorption, the modified method by microwave was superior to chemistry-microwave.Microwave modified PCACs were pressed into pellets using phenol-formaldehyde resin as the binder. After that, these pellets was further carbonized at 600℃and activated at the temperature from 700℃to 900℃. The effect of the binder content and the second activat temperature on properties of activated carbons in pellet such as the compressive streng bulk density and gasoline adsorption were investigated. Consequently, the optimal binder content and activation temperature was 30% and 800℃, respectively. The gasoline saturation adso:ption value of prepared activated carbon sample in pellet was 223 mg/g.Prepared activated carbon samples at optimized conditions from black liquor and coconut shell were evaluated for their properties and performance as electrode material in electric double layer capacitor. The results showed that the properties and performance of carbon materials from black liquor and coconut shell were similar. Carbon materials have stable electrochemical behavior and had specific capacitance values of 265 F/g and 204 F/g. The surface acidic functional groups of BLAC sample oxidized by hydrogen peroxide was increased by 15 times than non-oxidized BLAC sample. The specific capacitance values of BLACs oxidized was up to 332 F/g.