Abstract:

Carbon materials can be used as excellent adsorption desulfurization materials. Their sulfur dioxide (SO₂) capture performance is affected by physicochemical characteristics and desulfurization conditions. In this study, seven types of carbon materials were selected: activated carbon-1 (specific surface area was 1779m²/g, AC-1700), activated carbon-2 (specific surface area was 970m²/g, AC-900), porous nano-carbon-1 (average pore size was 14nm, NCP-10), porous nano-carbon-2 (average pore size was 85nm, NCP-100), porous nano-carbon-3 (average pore size was 4.7nm, nitrating, CMK-3N), porous nano-carbon-4 (average pore size was 4.1nm without nitrating, CMK-3) and carbon nanofibers (NCF). Based on the comparison of the physicochemical characteristic of these seven different carbon materials and their desulfurization performance, the effects of physicochemica properties, desulfurization temperature, reaction space velocity and so on on the SO₂ capture performance of carbon materials were studied. It provided guidance for the research and development of carbon materials and their composites with suitable physical and chemical properties and high desulfurization performance. The results showed that the SO₂ capture performance of carbon materials was comprehensive affected by the specific surface area, pore structure, surface functional groups, desulfurization temperature and reaction space velocity. The pore structure and surface functional groups of different carbon materials had great influence on the desulfurization performance of the carbon materials. The activated carbon AC-1700 and AC-900 with microporous structure had a higher SO₂ removal rate. The porous nano-carbon NCP-10, NCP-100, CMK-3N and CMK-3 with mesoporous structure had a higher desulfurization capacity. Oxygen functional groups and nitrogen functional groups can improve the adsorption performance of carbon materials for SO₂ capture. The process of SO₂ removal by carbon materials was mainly physical adsorption. The SO₂ capture performance of carbon materials decreased with increasing desulfurization temperature. Above 100℃, the SO₂ capture performance of carbon materials would be ineffective. The reaction space velocity had a great influence on the SO₂ capture performance of carbon materials. With the decrease of reaction space velocity, the SO₂ capture performance of carbon materials increased. When the reaction space velocity was low enough, carbon materials can effectively remove SO₂ pollution. In this study, porous nano-carbon NCP-10 had the best SO₂ capture performance, which can maintain 100% SO₂ removal rate at room temperature for 1 hour, and the 1 hour cumulative desulfurization capacity was up to \mathrm{108}\mathrm{m}{\mathrm{g}}_{\mathrm{S}{\mathrm{O}}_{\mathrm{2}}}/g_material at room temperature while maintaining a SO₂ removal rate of higher than 90%.

Key words: environment, carbon materials, adsorbents, sulfur dioxide removal, fixed-bed, desulfurization performance

摘要：

选用了7种不同物理化学特性的碳材料，分别为活性炭-1（比表面积1779m²/g）、活性炭-2（比表面积970m²/g）、多孔纳米炭-1（平均孔径14nm）、多孔纳米炭-2（平均孔径85nm）、多孔纳米炭-3（平均孔径4.7nm，掺氮）、多孔纳米炭-4（平均孔径4.1nm，不掺氮）和纳米碳纤维。在对比这7种不同的碳材料的物理化学特性与其脱硫性能的基础上，研究材料的物理化学特性、脱硫温度、反应空速等因素对碳材料吸附脱除SO₂性能的影响。结果表明，碳材料吸附脱除SO₂的性能受材料的比表面积、孔隙结构、表面官能团、脱硫温度和反应空速的综合影响。不同的碳材料中，材料的孔隙结构和表面官能团对材料的脱硫性能影响很大，以微孔结构为主的碳材料SO₂去除率较高，以介孔结构为主的碳材料脱硫容量较高；随着脱硫温度升高，碳材料的吸附脱硫性能降低；随着反应空速降低，碳材料的吸附脱硫性能升高。本研究中，多孔纳米炭NCP-10的吸附脱除SO₂性能最好，能在室温下保持100%的SO₂去除率持续1h，且在室温下1h内累积的脱硫容量最高可达108mg(SO₂)/g(材料)。

关键词: 环境, 碳材料, 吸附剂, 二氧化硫脱除, 固定床, 脱硫性能