The industrial applications of CaO-based adsorbents for CO capture are limited by the challenges of serious sintering in a realistic regeneration condition and elutriation in the fluidized-bed reactors. Although the granulation of CaO-based adsorbents has been extensively investigated, the key indexes such as mechanical strength, adsorption performance, and cyclic stability were investigated independently rather than united for practical applications. Here, we systematically investigated the impacts of binders on the mechanical properties and CO capture performance of CaO-based particles granulated using the extrusion method. Among different commercial binders (cement, kaolin, and bentonite), only cement yielded calcined CaO-based particles with the required mechanical strength. At the optimal cement proportion (10%) and particle diameter (3 mm), the “CaO+Cement” particle achieved a compressive strength of ≥20 N and an attrition rate of ≤5%. After granulating, the “CaO+Cement” particle retained a favorable CO uptake of 458 mg/g within 10 min, and also exhibited excellent cyclic performance in a realistic regeneration condition (calcination at 920 °C in a CO atmosphere), with a decay rate of 0.9% per cycle during long-term cycles. After 50 cycles, the cumulative CO uptake for “CaO+Cement” particle was 9.44 g/g, representing a marked increase of 42.9% compared with that of the pure CaO particle. Owing to those multiple advantages of excellent mechanical strength, CO adsorption performance, cyclic stability and economic cost, the “CaO+Cement” particle (with a cement proportion of 10% and a diameter of 3 mm) appears to be a promising material for CO capture from industrial flue gas at large-scale.

中文翻译：

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深入评估粘结剂对CaO基颗粒机械性能和CO2捕获性能的影响

用于 CO 捕获的 CaO 基吸附剂的工业应用受到现实再生条件下严重烧结和流化床反应器中淘析的挑战的限制。尽管CaO基吸附剂的造粒已被广泛研究，但机械强度、吸附性能和循环稳定性等关键指标是独立研究的，而不是联合起来用于实际应用。在这里，我们系统地研究了粘合剂对使用挤出法造粒的 CaO 基颗粒的机械性能和 CO 捕获性能的影响。在不同的商业粘合剂（水泥、高岭土和膨润土）中，只有水泥才能产生具有所需机械强度的煅烧 CaO 基颗粒。在最佳水泥配比（10%）和粒径（3 mm）下，“CaO+水泥”颗粒的抗压强度≥20 N，磨损率≤5%。造粒后，“CaO+水泥”颗粒在 10 分钟内保留了 458 mg/g 的良好 CO 吸收量，并且在现实再生条件下（在 CO 气氛中于 920 °C 下煅烧）也表现出优异的循环性能，并且衰减长期周期中每个周期的利率为 0.9%。经过50次循环后，“CaO+水泥”颗粒的累积CO吸收量为9.44 g/g，与纯CaO颗粒相比显着增加了42.9%。由于具有优异的机械强度、CO吸附性能、循环稳定性和经济成本等多重优点，“CaO+水泥”颗粒（水泥比例为10%，直径为3 mm）似乎是一种很有前途的CO材料大规模捕集工业烟气。