New activated carbon with high thermal conductivity and its microwave regeneration performance

Abstract

Using a walnut shell as a carbon source and ZnCl₂ as an activating agent, we resolved the temperature gradient problems of activated carbon in the microwave desorption process. An appropriate amount of silicon carbide was added to prepare the composite activated carbon with high thermal conductivity while developing VOC adsorption-microwave regeneration technology. The experimental results show that the coefficient of thermal conductivity of SiC-AC is three times as much as those of AC and SY-6. When microwave power was 480 W in its microwave desorption, the temperature of the bed thermal desorption was 10 °C to 30 °C below that of normal activated carbon prepared in our laboratory. The toluene desorption activation energy was 16.05 kJ∙mol⁻¹, which was 15% less than the desorption activation energy of commercial activated carbon. This study testified that the process could maintain its high adsorption and regeneration desorption performances.

Keywords

activated carbon with high thermal conductivity / activation energy for desorption / VOCs / microwave radiation

References

[1] Zhang ZY, Peng JH, Zhang LB, et al. Research Progress of Regenerating Activated Carbon by Microwave Heating[J]. Journal of Chemical Industry and Engineering, 2008, 28(1): 25-29.

[2] Cui J, Zhao NQ, Li JJ. Progress in Preparation of Activated Carbons[J]. Carbon Techniques, 2005, 24(1): 26-30.

[3] Zhao LY, Lü JM, Li QL, et al. Present Situation and Progress in Preparation of Activated Carbon[J]. Science Technology and Engineering, 2008, 8(11): 2914-2918.

[4] Ahmaruzzaman M. Adsorption of Phenolic Compounds on Low-cost Adsorbents: a Review[J]. Advance in Colloid and Interface, 2008, 143(2): 48-67.

[5] Zaher H, Hamidreza Emamipour. Concomitant Adsorption and Desorption of Organic Vapor in Dry and Humid Air Streams Using Microwave and Direct Electrothermal Swing Adsorption[J]. Environ. Sci. Technol., 2008, 42(24): 9317-9322.

[6] Harper M. Sorbent Trapping of Volatile Organic Compounds from Air[J]. Journal of Chromatography A, 2000, 885(1-2): 129-151.

[7] Aluisio CP, James EK. Oxidative Coupling and the Irreversible Adsorption of Phenol by Graphite[J]. Colloid and Interface Science, 2006, 293(2): 278-289.

[8] Meng G, Li a, Zhang Quanxing. Studies on the Oxygencontaining Groups of Activated Carbon and Their Effects on the Adsorption Character[J]. Ion Exchange and Adsorption, 2007, 23(1): 88-94.

[9] SU Z, PAN N, ZHAO W, et al. Preparation and Properties of Activate Dcarbons with High Thermal Conductivity[J]. Chemilal Engineering, 2012, 40(12): 14-18.

[10] PAN N, SU Z, MO J, et al. Preparation of Novel Composite Activated Carbon with High Applicability to Microwave and Its Regeneration under Microwave Radiation[J]. CIESC Journal, 2011, 62(1): 111-118.