What parameters are related to the purity and yield of hydrogen in PSA products?

If considering the pure hydrogen side, hydrogen purity is inversely related to yield.

What was said on the second floor is right! ! In PSA products, the purity of hydrogen is inversely proportional to the yield; the higher the purity, the lower the yield.

Under the same operating pressure conditions, in a PSA hydrogen purification unit, the purity of hydrogen is inversely proportional to the hydrogen recovery rate; that is, the higher the purity of hydrogen, the lower the recovery rate, and vice versa. PSA hydrogen purification principle: It takes advantage of the selectivity of adsorbents toward different adsorbates, as well as the fact that the amount of adsorption of these adsorbates by the adsorbents varies under different pressure conditions. Under high pressure, the adsorbates are absorbed by the adsorbents; at low pressure, the adsorbents lose their ability to adsorb these adsorbates, causing them to be released and thus enabling the regeneration of the adsorbents. (The adsorbate: here it refers to other impurity components other than the hydrogen component.) Therefore, for PSA to operate at its designed specifications, the operating pressure must reach the design value. At the same time, the regeneration capacity of the adsorbent is also related to the operating purity and yield. If the regeneration capacity of the adsorbent is poor, the impurity components adsorbed on it cannot be removed; when raw material is introduced again, the adsorbent becomes saturated with these impurity components, which then penetrate through the adsorption bed and enter the product gas, resulting in a decrease in the purity of the product gas. When such operating conditions occur, the only options are to reduce the operating time of the PSA, decrease the processing capacity of the feed gas, and at the same time increase the amount of purge gas or the vacuum time used for washing the adsorbent. Compared to normal conditions, the number of desorption and regeneration cycles of the adsorption tower increases within the same time period, the amount of air released increases, and the yield of the hydrogen component decreases.

(1) Raw gas composition: The processing capacity of the absorption tower is highly dependent on the composition of the raw gas. The higher the hydrogen content in the feed gas, the greater the processing capacity of the adsorption tower ； The higher the impurity content in the feed gas, especially the level of harmful impurities for which high purification requirements apply, the lower the processing capacity of the adsorption tower. (2) Raw gas temperature: The higher the temperature of the raw gas, the lower the adsorption capacity of the adsorbent, and the lower the processing capacity of the adsorption tower. (3) Adsorption pressure: The higher the pressure of the feed gas, the greater the amount of material that can be adsorbed by the adsorbent, and thus the higher the processing capacity of the adsorption tower. (4) Desorption pressure: The lower the desorption pressure, the more thorough the regeneration of the adsorbent, the greater its dynamic adsorption capacity, and the higher the processing capacity of the adsorption tower. (5) Product purity: The higher the product purity, the lower the effective utilization rate of the adsorbent, and the lower the processing capacity of the adsorption tower.

The higher the purity, the lower the yield; they are inversely related. However, high hydrogen purity facilitates the regeneration (washing) of the adsorbent. Usually, when we consider the purity of hydrogen, we refer to a CO content of less than 10 ppm

It is mainly related to the adsorption time: the longer the adsorption time, the higher the yield, but the purity decreases; conversely, the shorter the time, the lower the yield and the higher the purity