National Energy Technology Laboratory, United States Department of Energy, Pittsburgh, Pennsylvania 15236, USA.
J Chem Phys. 2010 Aug 21;133(7):074508. doi: 10.1063/1.3473043.
By combining density functional theory and lattice phonon dynamics, the thermodynamic properties of CO(2) absorption/desorption reactions with alkaline earth metal oxides MO and hydroxides M(OH)(2) (where M=Be,Mg,Ca,Sr,Ba) are analyzed. The heats of reaction and the chemical potential changes of these solids upon CO(2) capture reactions have been calculated and used to evaluate the energy costs. Relative to CaO, a widely used system in practical applications, MgO and Mg(OH)(2) systems were found to be better candidates for CO(2) sorbent applications due to their lower operating temperatures (600-700 K). In the presence of H(2)O, MgCO(3) can be regenerated into Mg(OH)(2) at low temperatures or into MgO at high temperatures. This transition temperature depends not only on the CO(2) pressure but also on the H(2)O pressure. Based on our calculated results and by comparing with available experimental data, we propose a general computational search methodology which can be used as a general scheme for screening a large number of solids for use as CO(2) sorbents.
通过结合密度泛函理论和晶格声子动力学，分析了碱性土金属氧化物 MO 和氢氧化物 M(OH)(2)（其中 M=Be、Mg、Ca、Sr、Ba）与 CO(2) 吸收/解吸反应的热力学性质。计算了这些固体在 CO(2)捕获反应中的反应热和化学势变化，并用于评估能量成本。相对于在实际应用中广泛使用的 CaO，MgO 和 Mg(OH)(2)系统由于其较低的操作温度（600-700 K），被认为是更好的 CO(2)吸附剂应用候选者。在 H(2)O 的存在下，MgCO(3)可以在低温下再生为 Mg(OH)(2)，或在高温下再生为 MgO。这种转变温度不仅取决于 CO(2)压力，还取决于 H(2)O 压力。基于我们的计算结果，并与可用的实验数据进行比较，我们提出了一种通用的计算搜索方法，可作为筛选大量用于 CO(2)吸附剂的固体的一般方案。
