Effect of the surface properties of an activated coke on its desulphurization performance

• Published in: Mining science and technology (China) 2009-11, Vol.19 (6), p.769-774
• Main Authors: ZHANG, Xiang-lan, ZHANG, Yan, DING, Fang-sheng, HUANG, Qi-jiang, LI, Yuan
• Format: Article
• Language: English
• Subjects: activated coke; desulphurization property; surface property; 吸附能力; 总氮含量; 气相色谱; 氮官能团; 活性焦; 脱硫性能; 表面性质; 过氧化氢
• ISSN: 1674-5264; 2212-6066
• DOI: 10.1016/S1674-5264(09)60140-X

Commercial coke was modified by H2O2 and/or NH3.H2O to obtain an activated coke containing additional oxygen functional groups and/or nitrogen functional groups. The aim of the modification was to enhance the SO2 adsorption capacity of the activated coke. Several techniques, including total nitrogen content measurements, SO2 adsorption, XPS and FTIR analysis, were used to characterize the coke samples. The XPS and FTIR spectra suggest the existence of -CONH2 groups in the H2O2 plus ammonia modified coke. The SO2 adsorption capacity of an activated coke increases slightly with an increase in H2O2 concentration during the modification process. The desulphurization performance of a modified coke is considerably enhanced by increasing the treatment temperature during ammonia modification. The amount of nitrogen in a coke modified by H2O2 plus NH3.H2O is the highest, and the SO2 adsorption capacity of the coke is also the highest （89.9 mg/gC）. The NH3.H2O （only） modified sample has lower nitrogen content and lower desulphurization capacity （79.9 mg/gC）. H2O modification gives the lowest SO2 adsorption capacity （28.9 mg/gC）. The H2O2 pre-treatment is beneficial for the introduction of nitrogen onto the surface of a sample during the following ammonia treatment process.