Study On A New Method For Preparation Of Coal-based Activated Carbon Combined With Hydrogen

Effective ways are considerated and researched all over the world, due to energy problem in the face of double pressures from both resource and environment. Coal poly-generation technologies receive much concern, beause of its integration of resource, energy and environment. In order to reduce CO2 emission when preparation hydrogen from coal, coupling-activation technolgy of"hydrogen-carbon material"was discussed in the thesis.Activated carbon and hydrogen were prepared by coupling-activation from Shenfu 3# coal. KOH or NaOH was used as chemical activator, while steam was physical activator. The influence of various parameters on the adsorption capacity of activated carbon and the yield of hydrogen were investigated. The experimental results showed that KOH, NaOH and their mixture had different influence on properties of activated carbon. When using KOH or NaOH as chemical activator, the iodine number of activated carbon increased at first then decreased with temperature and impregnation ratio, but the methylene blue adsorption value increased quickly at first then changed little. The adsorption value increased at first then decreased with total activation time. When the mixture of KOH and NaOH was used as chemical activator, the iodine number of activated carbon decreased at first then increased with the ratio of KOH and NaOH, and the methylene blue adsorption value had a decreasing trend. Hydrogen yield produced during coupling-activation increased with temperature, or impregnation ratio, or activation time.The experimental results showed that the specific surface area of activated carbon was 986 m2/g, and pore volume and average pore diameter of activated carbon was 0.309 m3/g, 3.094 nm respectively, and the iodine number was 851 mg/g, methylene blue adsorption value was 431 mg/g at an temperature of 700℃, an impregnation ratio of 0.5 using KOH, total activation time of 60 min and unit-activation time of 10 min. Also, a large amount of hydrogen was released during the activation, about 33.116 Nmmol for each gram of coal, up to more than 63.6% of total gaseous products.It indicated that chemical activation agents was regenerated in physical activation unit, and also catalysed physical activation. Hydrogen was abtained during both physical activation unit and chemical activation unit. Porous structure of activated carbon and hydrogen yield could be controlled according to change impregnation ratio of KOH and coal, or activation temperature or activation time or steam flow rate.