Preparation And Properties Of Activated Carbon Monoliths With High Specific Surface Area

Activated carbon monoliths (ACMs) have been successfully prepared from a commercial high surface area activated carbon using B1 and B2 as binder, separately. Process parameters on products'properties (compressive strength, bulk density and iodine adsorption value) were investigated. The microstructures of the carbons were studied by scanning electron microscopy (SEM) and N2 adsorption. ACM prepared under the optimum conditions has been used in benzene adsorption. PAC and ACM has been successfully prepared from a coal liquefaction residue (CLR). The mechanism of ACM's formation was discussed. The main results are as follows:(1) High-strength ACM has been successfully prepared from a commercial high surface area activated carbon powder through mixing, moulding, curing and carbonizing using B1 as binder. The optimum synthetic parameters of phenolic resin-based ACM was confirmed by investigating the effect of powdered activated carbon added on compressive strength and iodine adsorption ability of ACM. The results showed that activated carbon monolith with specific surface area of 797m2/g (30%to the PAC) and bulk density of 0.909 g/cm3, and compressive strength of 342.8 N/cm when 70%of phenol formaldehyde resin was used under molding pressure of 30 MPa and carbonization at 700℃.(2) High specific surface area activated carbon monoliths have been successfully prepared from a commercial high specific surface area powdered activated carbon and B2 used as adhesive. The effect of adhesive added and heat treatment time on the compressive strength, bulk density and iodine adsorption value of the products has been investigated. The results show that activated carbon monolith with high specific surface area of 2244 m2/g (85% to the PAC) and also high compressive strength of 299.3 N/cm (much higher than commercial ACM) can be obtained when 12.5%of adhesive was used under molding pressure of 5 MPa and heat treatment at 200℃for 30 min. Application in benzene adsorption shows that the as-made ACM's volume adsorption capacity of benzene was higher than H-PAC.(3) CLR-PAC has been successfully prepared from coal liquefaction residue through oxidation-activation step, and CLR-ACM was prepared from CLR-PAC through mixing, moulding, and heat treatment using B2 as binder. The effect of two different powder activated carbons and two different binders on formation mechanism of ACMs was investigated. In this experiment, the ACM prepared from a commercial high specific surface area powdered activated carbon and B2 used as adhesive has a best overall performance (specific surface area, bulk density and compressive strength).