Melamine Modification of Spherical Activated Carbon and Its Effects on Acetylene Hydrochlorination

Commercial spherical activated carbon（SAC） was modified by impregnation to enhance the catalytic properties of SAC in acetylene hydrochlorination through melamine modification. Different modification conditions for SAC with nitrogen were compared by changing the SAC-Melamine ratios. The effect of carbonization temperature on the modification was also investigated. Surface chemistry and adsorption properties of the modified and unmodified SACs were studied by scanning electron microscope（SEM）, X-ray photoelectron spectroscopy（XPS）, elementary analysis, BET, and temperature-programmed desorption（TPD）. Moreover, the catalytic properties of SAC in acetylene hydrochlorination under differently modified conditions were also investigated. Elemental analysis showed that the nitrogen content of the modified SAC was greatly improved. XPS revealed that nitrogen mainly exists in Pyrrole nitrogen and Pyridine nitrogen. TPD showed that desorption of C2H2 was changed by modification. The conversion rate of acetylene was up to 70% under the following reaction conditions： temperature, 150 ℃; C2H2 hourly space velocity（GHSV）, 36 h-1; feed volume ratio V（HCl）/V（C2H2） = 1.15. The catalytic properties of SAC were improved significantly via melamine modification.