Research On Activated Carbon Monolith And Its Performance Of Natural Gas Adsorption

Activated carbon is widely used in many fields as an important adsorbent and catalyst supporter due to its special porous texture and surface chemical property. Powdered activated carbon made by conventional method is difficult to use because of dust pollution. However, activated carbon monolith (ACM) has the advantages of no dust pollution and higher adsorption capacity per volume compared with powdered activated carbon. Natural gas has been widely used as vehicle fuel. Adsorption storage of natural gas has many advantages such as lower pressure of storage, safety and so on. This technique has a good prospect. Activated carbon monolith is a good adsorbent for storage of natural gas, and the key problem is how to prepare activated carbon monolith with high surface area and good mechanical strength.The preparation of activated carbon monolith with three different methods was studied in this article. It was found that the iodine number of ACM prepared with CMC and different raw material was smaller than that of raw material after heat treatment. With the increasing volume of CMC, the iodine number of ACM prepared with same material decreased, but the mechanical strength increased. The specific surface area of ACM prepared by tar and subsequent activation of CO2 was higher than ACM prepared only with tar. Its pore size distribution broadened, but the mechanical strength decreased dramatically. Moreover, the wearing strength of ACM was poor. With the added volume of KOH increased, the iodine number of ACM prepared by tar, KOH and GAC increased and then decreased. When the large amount of KOH added, the iodine number of ACM increased dramatically, however, when KOH/GAC mass ratio come to 0.5, the mechanical strength reached the highest value. With the addition of KOH, the micropore volume and mechanical strength of ACM prepared by tar, KOH and SAC is higher than the ACM prepared without KOH. With the increase of KOH, the specific surface area and pore volume increased, the mechanical strength improved slightly. Comparing the three methods, we find that the first method is suitable for the preparation of ACM by super activated carbon, whereas the third method is suitable for the preparation of ACM by powdered activated carbon with lower iodine number.The adsorption volume of natural gas with different ACM was also studied in this article. The study found that natural gas adsorbed on ACM is mainly the physical adsorption. The volume adsorbed is in direct proportion to the iodine number of ACM. However, the raw materials for the preparation of ACM have no effect on the volume of natural gas adsorbed on ACM.