Abstract
A series of simulation tests were performed with H2, D2 and CH4 to study the characteristics of detritiation system composed of catalytic oxidizer packed with precious-metal-alumina catalyst, dryer with molecular sieve 5A, and so on. The amount of water vapor adsorbed on the catalyst came up to more than 10% of that on the molecular sieve 5A. Conversion ratio for D2 as high as 99.9% were obtained in the following conditions: space velocity: 1, 800-5, 100h-1, catalyst bed temperature: 23-100°C. The effect of the adsorbed water on the conversion ratio was not detected. The ratio for CH4 under the constant space velocity, i.e. 2, 000h-1, exceeded 99% at the temperature higher than 350°C. Maximum reduction ratio of the water vapor by the dryer was 99.9998%. Enclosure cleanup ratios in the high concentration range of D2 and CH4 were demonstrated to approach exponential dilution.
It is noticed that careful consideration on the effects of the adsorbed water should be payed for evaluating the catalyst performance, and soaking effect on the inner surface of the enclosure could not be neglected in the low concentration range of hydrogen.
