Ortho-Parahydrogen Mixer, Catalysts, Measurement Devices and their Application

27th International Cryogenics Engineering Conference and International Cryogenic Materials Conference 2018

Klaus, M.^1 ; Schwab, A.^1 ; Haberstroh, Ch^1 ; Eckhardt, K.^2 ; Beßler, Y.^3 ; Baggemann, J.^4 ; Cronert, T.^4

Institute of Power Engineering, Technische Universitat Dresden, Dresden

01069, Germany^1

Department of Inorganic Chemistry, Technische Universitat Dresden, Dresden

01069, Germany^2

ZEA-1, Forschungszentrum Jü Lich GmbH, Jü lich

52425, Germany^3

JCNS-2, Forschungszentrum Jülich GmbH, Jülich

52425, Germany^4

关键词: Catalyst conversion;    Concentration determination;    Industrial catalyst;    Low temperatures;    Measurement device;    Neutron moderation;    Rapid conversion;    Spin configurations;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/502/1/012161/pdf
DOI  :  10.1088/1757-899X/502/1/012161

来源: IOP

【 摘 要 】

For the majority of low temperature hydrogen applications the ortho-to parahydrogen (o-p-H2) spin configuration plays a vital role. Examples are liquid storage (heat of conversion) or neutron moderation (unequal cross section). Decreasing temperatures below ambient imply higher equilibrium p-H2 ratios. Often, rapid conversion close to the equilibrium is beneficial. The rather slow natural conversion can be sped up for example by catalytic contact to paramagnetic substances. For this, the paper gives an overview on published isothermal conversion catalyst data at LN2 temperature. Furthermore, an enhanced Catalyst Test Cryostat (CTC) facilitating new adiabatic and isothermal o-p-H2 catalyst conversion measurements is presented. Precise concentration determination is decisive. Hence, two commercial analyzers, essential for isothermal conversion measurements, using speed of sound or thermal conductivity will be compared to the performance of the independent adiabatic CTC results. Obtained activity data on an industrial catalyst at ≈77.3 K will be provided. Finally, a novel process, batch and closed cycle, providing mixtures with p-H2 contents ranging from 0.25 to ≈1.00 is introduced. The latter enables e.g. neutron moderation at stable, non-equilibrium o-p-H2 ratios.