SO2 removal from flue gas by activated semi-cokes -: 1.: The preparation of catalysts and determination of operating conditions

The objective of this work was to use waste semi-coke as the raw material to prepare catalysts of industrial-scale size for SO2 removal from flue gas and to find the optimal preparation methods. Results showed that lignite semi-coke was a suitable raw material, and that the catalyst, prepared by pre-activating in an autoclave, oxidizing with HNO3, loading with CuSO4 and finally calcining at 700 degreesC, exhibited the best desulfurizing property with a sulfur retention of about 9.6% SO2/100 gC at a reaction temperature of 90 degreesC. Also, the effects of H2O content in the flue gas, reaction temperature and space velocity on the desulfurizing property were investigated to determine optimum operating conditions. An H2O content of 7% was appropriate for catalysts in this work. In the temperature range 80-120 degreesC, the catalyst showed good performance for SO2 removal and was gradually deactivated at temperatures above 120 degreesC. Space velocity exhibited an optimal value of 830 h(-1). The kinetic behavior varied with space velocity and the desulfurizing property was controlled by diffusion at space velocities below 830 h(-1), and controlled by adsorption or catalytic reaction at space velocities above 830 h(-1). (C) 2003 Elsevier Ltd. All rights reserved.