International Journal of Greenhouse Gas Control ( IF 3.9 ) Pub Date : 2018-05-10 , DOI: 10.1016/j.ijggc.2018.04.022 Justin R. Finn , Janine E. Galvin
Very high rates of CO2 absorption have been demonstrated using semipermeable microcapsules filled with environmentally benign sodium carbonate solutions (Vericella et al., Nature communications 6, 2015). However, such capsules have also exhibited several traits, including water loss/uptake, elastic swelling and buckling, and precipitation of solids, which make them more complicated to engineer as a carbon capture material. To address this, a mechanistic model for mass transfer and chemical reaction has been developed, which accounts for these behaviors, and can be used as a predictive tool to explore capsule performance under different CO2 capture scenarios. The model uses a modified film theory to describe CO2 and H2O mass transfer rates, a concentration based description of vapor-liquid-solid equilibrium inside the capsule, and an elastic description of the capsule shell. Model predictions compare favorably to literature data for precipitating carbonates, as well as recent data for microcapsule CO2 absorption. The model was used to assess practical issues of capsule water transfer during a temperature swing CO2 absorption/desorption cycle. Model predictions indicate that capsules filled with high weight percent, precipitating sodium carbonate solution could be significantly or completely dehydrated during CO2 absorption. Subsequent rehydration of lean capsules at elevated temperature showed strong sensitivity to both gas humidity, and capsule shell elasticity.
中文翻译:
半透性弹性微胶囊捕获CO 2的建模与仿真
使用充满环境友好的碳酸钠溶液的半透性微胶囊已证明了很高的CO 2吸收率(Vericella等人,Nature communications 6,2015)。但是,这样的胶囊还表现出一些特性,包括失水/摄取,弹性膨胀和屈曲以及固体沉淀,这使得它们更难以工程化为碳捕获材料。为了解决这个问题,已经开发了一种用于传质和化学反应的机制模型,该模型考虑了这些行为,并且可以用作预测工具,以探索在不同的CO 2捕集情况下的胶囊性能。该模型使用改进的薄膜理论来描述CO 2和H 2O的传质速率,胶囊内部基于浓度的气-液-固平衡描述以及胶囊壳的弹性描述。模型预测与沉淀碳酸盐的文献数据以及微囊CO 2吸收的最新数据相比具有优势。该模型用于评估温度变化的CO 2吸收/解吸循环过程中胶囊水传输的实际问题。模型预测表明,充满高重量百分比的沉淀碳酸钠溶液的胶囊在吸收CO 2的过程中可能会明显或完全脱水。瘦胶囊随后在高温下再水合显示出对气体湿度和胶囊壳弹性的强烈敏感性。