Abstract:

Ortho-para hydrogen conversion catalyst (OPC) is one of the key materials in large-scale hydrogen liquefaction projects. In recent years, research primarily focuse on enhancing low-temperature catalytic activity of existing systems, while accurate measurement of para-hydrogen content has become the foundation of such studies. However, only a limited number of studies and relevant industry standards have reported the testing accuracy and reliability of para-hydrogen analysis, and the optimization of batch preparation process, all of which could not meet the requirement of domestic industrial development to reduce reliance on imported catalysts. This study explores both catalytic testing analysis and optimization of mass production processes for OPC, demonstrates the stability and high measurement accuracy of the experimental self-developed testing platform, and identifies the optimal mass production process combination to maximize yield through comprehensive comparison on catalytic performance and mechanical strength. Furthermore, process optimizations such as low-temperature activation, particle size optimization and secondary washing are implemented to produce catalysts with superior catalytic activity. The results show that the self-developed catalyst 2# with primary crushing, sieving through a 0.8 mm sieve, washing and low-temperature activation exhibits approximately 3.4% higher catalytic performance than imported catalysts at a space velocity of 1.2 L/(min·mL), with corresponding conversion rate and reaction rate constant (k value) approximately 7.42% and 25.78% higher, respectively. This study provides a kind of self-developed catalyst with excellent performance for domestic substitution through optimizing batch preparation.

Key words: ortho-para hydrogen conversion, catalyst, testing analysis, low-temperature catalytic activity, batch preparation process