• 关键词：CO₂分离  化学链燃烧  CaSO₄载氧体  载氧体再生  CaS氧化

• 基金项目：国家自然科学基金项目(No.90610016);国家重点基础研究发展计划(973)项目(No.2006CB20030201,2006CB705806);国家高技术研究发展计划(863)项目(No.2006AA05Z318)

• 郑敏
• 东南大学热能工程研究所, 南京 210096

• 沈来宏
• 东南大学热能工程研究所, 南京 210096

• 高正平
• 东南大学热能工程研究所, 南京 210096

• 肖军
• 东南大学热能工程研究所, 南京 210096

• 摘要：在热重和红外联用进行等温实验的基础上,探讨了氧体积分数为10%、20%,970～1150℃温度范围内化学链燃烧过程中钙基载氧体再生(CaS)的氧化特性.结果显示,CaS氧化的直接产物主要为CaSO₄,只有在诱导期生成极少量CaO和SO₂;但CaSO₄与CaS还可进一步反应,生成更多CaO和SO₂.通过对氧气浓度和温度的实验条件改变,研究了CaSO₄的转化率、转化速率,并辅以SO₂析出速率分析,获得了CaSO₄相对于CaO的瞬时选择性、CaSO₄的收率和反应选择率.结果表明,钙基载氧体CaSO₄再生过程氧化反应的适宜条件为温度970～1000℃以及较高的氧气气氛,这不仅可以抑制SO₂的排放量从而得到较高的反应选择率,同时反应过程也具有较高的转化速率.

• Abstract：Oxygen carrier regeneration by CaSoxidation at different oxygen concentrations (10% and 20%) and at different temperatures (from 950℃ to 1150℃) was studied based on isothermal tests with thermogravimetric analysis (TGA) and Fourier Transform Infrared (FT-IR) spectroscopy. The results revealed that CaSwas oxidized to CaSO₄ directly, with a small amount of CaOand SO₂ being formed during the induction period. However, the product CaSO₄ further reacted with the reactant CaSvia a solid-solid reaction to form more CaOand SO₂. The influences of oxygen concentration and temperature on the conversion ratio and the conversion rate of CaSO₄ are discussed. From the SO₂ evolution rate, the transient selectivity of CaSO₄ for CaSoxidation was also obtained, along with the CaSO₄ yield and the selectivity of regeneration reaction. The optimum conditions are as follows: the air reactor should be between 970℃ and 1000℃ and at a high oxygen concentration to prevent SO₂ emission. Thus, improved selectivity of the CaSO₄ regeneration reaction and a relatively high reaction rate could be obtained.

• Key words：CO₂ capture  chemical-looping combustion  CaSO₄ oxygen carrier  oxygen carrier regeneration  CaS oxidation

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