Fundamental Study and Reactor Development on Absorption and Desorption of Carbon Dioxide Using High Thmperature Molten Salt Slurry

本研究于2007-2008年进行，目的是在循环浆液泡柱中，硅酸锂细颗粒在高温下悬浮于熔融碳酸锂钾中，获得二氧化碳吸收和解吸的基本数据。总结如下：1。CO_2气泡在熔盐浆中的溶解与溶出行为分析在热反应器中制备了硅酸锂微粒和碳酸锂钾熔液。将含20% CO_2和80% N_2的模型烟气送入反应器。通过测量反应器内CO_2的质量平衡，观察了硅酸锂质量和熔盐组成改变时的CO_2吸收量。通过反应器排出气体中CO_2浓度的时间变化，测定了CO_2在熔盐中的最大吸收率和溶解度。研究了进气流量、熔盐成分和料浆浓度对气泡行为的影响。另一方面，研究了反应器升温至解吸温度时CO_2的汽提行为。讨论了硅酸锂质量、温度和升温速率对CO_2汽提率的影响。在本研究中，限制过程是CO_2分子在熔盐中的转移，即气泡中CO_2的溶解控制了整个反应速率。为了对常温下高温反应器内的气液固流体力学进行实验模拟，采用冷态模型。采用1微米PVC颗粒代替硅酸锂颗粒，表面活性剂水溶液作为熔盐模拟液。利用设计的循环浆泡塔，对气含率和液体循环速率进行了研究，以了解其应用于工业的基本信息。

The study has been done for 2007-2008 to obtain the fundamental data in terms of the absorption and desorption of carbon dioxide using a circulating slurry bubble column in which lithium silicate fine particles are suspended in molten lithium-potassium carbonate at high temperature.That was summarized as follows :1. Analysis of dissolution and stripping behavior of CO_2 bubble into molten salt slurryThe lithium silicate fine particles and molten Li-K-carbonate were prepared in the hot reactor. The model flue gas which has 20% CO_2 and 80% N_2 was fed into the reactor. The absorbed CO_2 was observed by measuring mass balance of CO_2 in the reactor when the mass of lithium silicate and the composition of molten salt were changed. Maximum absorption rate and solubility of CO_2 in molten salt were measured by the time course of CO_2 concentration in effluent gas from the reactor. The effects of influent gas flow rate, composition in molten salt and slurry concentration on gas bubble behavior were investigated.On the other hand, the stripping behavior of CO_2 was investigated when the reactor was heated up to the desorption temperature. The effects of the mass of lithium silicate, temperature and heating rate on the stripping rate of CO_2 were discussed. In this study, the limited process was the CO_2 molecular transfer in the molten salt, that is, CO_2 dissolution from bubbles governed the overall reaction rate.2. Hydrodynamics in circulating slurry bubble columnTo experimentally simulate the gas-liquid-solid hydrodynamics in high temperature reactor under the room temperature, the cold model was used. The 1 micron PVC particles was used as instead of lithium silicate particles and the surfactant aqueous solution was used as a imitation liquid of molten salt. By using a designed circulating slurry bubble column, the gas holdup and the circulation rate of liquid were investigated to know the fundamental information to apply for industry.