Membrane assisted fluidized bed reactor: Hydrodynamics, heat transfer and reactor demonstration

膜辅助流化床反应器：流体动力学、传热和反应器演示

• 批准号: 27255698
• 负责人: Professor Dr.-Ing. Stefan Heinrich
• 金额: --
• 依托单位: Institut für Feststoffverfahrenstechnik und Partikeltechnologie V-3
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/27255698?language=en
• 关键词: Membrane; assisted; fluidized; bed; reactor

Objective:The objective of the project is to develop a new kind of reactor by integration of membranes in the fluidized bed, which will either enable full control of the reaction heat generated by controlled dozing of the limiting reactant (e.g. smart dozing of oxygen in partial oxidation reactions) or enhanced conversions and selectivity to the desired product by selective removal of one of the products (e.g. hydrogen removal in dehydrogenation reactions), and which will also give an optimal balance between the bubble-to-emulsion mass transfer and the tube-to-bed heat transfer in the fluidized bed.Procedure:Microporous non-selective membranes with different configurations (vertical or horizontal) will be integrated in the bubbling fluidized bed. The presence of membranes as internals as well as addition or removal of gas via the membranes can have significant effect on the bubble size, bubble to emulsion mass transfer, emulsion porosity, emulsion heat capacity and tube-to-bed heat transfer coefficient. The effect of presence of membranes and the gas addition or removal via the membranes on the bubble size variation at various fluidization velocities will be studied using pressure fluctuation measurements. Similarly, the effect on the emulsion phase porosity, solid concentration in the emulsion, thickness of the gas film at the heat transfer surface, heat transfer surface renewal rate by emulsion packet will be measured using optical fiber probe and effect of these properties on the immersed surface-to-bed heat transfer will be determined by simultaneous measurements of heat transfer. Finally the reactor concept will be demonstrated for partial oxidation of ethylene to ethylene oxide and the experimental results will be predicted by developing phenomenological models incorporating gas addition via the membranes. Experiments with conventional fluidized bed reactor will be carried out as reference.

目的：本项目的目标是通过在流化床中集成膜来开发一种新的反应器，该反应器将能够完全控制由限制性反应物的受控定量给料产生的反应热（例如，在部分氧化反应中的氧气的智能投料）或通过选择性去除产物之一而提高转化率和对所需产物的选择性（例如脱氢反应中的氢气去除），并且这也将在流化床中的气泡-乳液传质和管-床传热之间给出最佳平衡。将具有不同结构（垂直或水平）的微孔非选择性膜集成在鼓泡流化床中。作为内部构件的膜的存在以及经由膜添加或去除气体可以对气泡尺寸、气泡到乳液的传质、乳液孔隙率、乳液热容和管到床的传热系数具有显著影响。将使用压力波动测量来研究膜的存在和气体通过膜的添加或去除对在各种流化速度下的气泡尺寸变化的影响。类似地，将使用光纤探针测量对乳液相孔隙率、乳液中的固体浓度、传热表面处的气膜厚度、由乳液包引起的传热表面更新速率的影响，并且将通过同时测量传热来确定这些性质对浸没的表面至床层的传热的影响。最后，反应器的概念将被证明为部分氧化乙烯环氧乙烷和实验结果将通过发展的现象学模型，将气体通过膜添加预测。以常规流化床反应器为参考进行实验。