中温加压下镁基吸附剂CO_2吸附和再生性能研究

CO_2 Adsorption and Regeneration Properties of a Magnesium-Based Sorbent under Moderate Temperature and Pressured Condition

以一种镁基前驱物和一种矿物黏结剂为原料,采用湿混法经煅烧及水合制备得到镁基吸附剂,考察了吸附温度和吸附压力对其CO2吸附性能的影响,并利用XRD、SEM和BET对其理化性质进行了表征。结果表明:镁基吸附剂经水合后的活性组分为Mg(OH)2,当吸附温度为300℃、吸附压力为2MPa时其CO2穿透吸附量达3.93mmol/g;吸附剂水合过程中生成叶蛇纹石,降低了Mg的利用率,吸附过程中在吸附剂表面生成的块状产物层阻碍了CO2内扩散的进行;在中温加压条件下此吸附剂能够达到稳定的18次吸附-再生循环,适用于整体煤气化联合循环发电(IGCC)系统中CO2的脱除。

A magnesium-based precursor and a binder were used to prepare a magnesium-based sorbent by wet mixing method after the process of calcination and hydration. The effects of temperature and pressure on the adsorption properties of the sorbents were investigated. Physicochemical properties of the sorbents were characterized by XRD, SEM and BET. It was indicated that the active component of the hydrous sorbent was Mg（OH）2, whose breakthrough capacity of CO2 reached 3. 93 mmol/g under the condition of 300 ℃ and 2 MPa. Antigorite formed in the process of hydration reduced the utilization efficiency of Mg. Block product layer formed on the surface of the adsorbent in the adsorption process restricted the internal diffusion of CO2. The sorbent could perform 18 stable cycles of sorption-regeneration under moderate temperature and pressured condition, which was suitable for CO2 capture in IGCC.