A high-precision experimental measurement system and method for the parahydrogen concentration and the Ortho-Para hydrogen catalyst's catalytic performance

Abstract

An experimental system that combines the measurement of parahydrogen concentration with the assessment of ortho-para hydrogen catalyst's catalytic performance was created for this investigation. The concentration of parahydrogen was detected by a thermal conductivity detector integrated into the gas chromatograph. The catalyst sample and the generator of standard gas were integrated into one experimental setup for easier operation. Meanwhile, a new method for catalytic performance evaluation of ortho-para hydrogen catalyst was developed based on this system. This method can decrease test time and yield more valuable test results than the conventional way. Throughout the experiments, the system's dependability was increased by optimizing the utilization of the carrier gas. The deviation analysis and repeatability verification of the relevant test data showed that the relative standard deviation was less than 0.35% and the mean value of the variation coefficient was less than 0.20%, which demonstrated the method had high accuracy, stability, and reliability. Further studies have shown that the catalysts should be densely packed inside the converter and kept out of the air to maximize their catalytic activity. These pertinent findings regarding the application of ortho-parahydrogen catalysts in this study can guide the design of the ortho-parahydrogen converter in actual hydrogen liquefiers. Moreover, the method and the procedure proposed in this study may contribute to the optimization of the ortho-parahydrogen catalyst production process as well as the calibration of the parahydrogen concentration in liquid hydrogen products.