Some Preliminary Thoughts on Recovery Rate Analysis

Oxygen recovery rate refers to the degree of oxygen recovery from the air, and it is an important indicator for evaluating a set of equipment. The oxygen recovery rate of PSA oxygen generation units directly reflects the efficiency of oxygen utilization, and it is generally calculated as a percentage of the absolute amount of oxygen in the product gas compared to the absolute amount of oxygen in the air. η = (P × Xp) / (F × XF) (1) Where η is the oxygen recovery rate, % ； P and F represent the flow rates of oxygen and air, respectively, in L/min ； Xp and XF represent the oxygen contents in air and product gas, respectively, in %. Effect of pressure on oxygen recovery rate: By adjusting the pressure at the oxygen outlet, while keeping the inlet air flow rate, oxygen production process, oxygen flow rate, and system pressure constant, the impact of these changes on the oxygen recovery rate was examined. A decrease in the outlet pressure leads to a reduction in the oxygen recovery rate, primarily because as the outlet pressure drops, the oxygen flow rate fails to remain at a constant level; this reduction in flow rate results in a decrease in the total amount of gas produced. The oxygen concentration in the product gas decreases as the outlet pressure increases

With the inlet air flow rate, oxygen production process, oxygen output flow rate, and oxygen outlet pressure held constant, the oxygen recovery rate increases at first and then decreases as the system pressure rises. This indicates that, depending on the different adsorbents and adsorption processes, there is an optimal adsorption pressure range within which the oxygen recovery rate is highest and the oxygen concentration is best.

Selecting and developing efficient adsorbents is an effective way to improve the oxygen recovery rate. The adsorption process plays a key role in the oxygen recovery rate. With the inlet air flow rate, oxygen production process, system pressure, and oxygen outlet pressure kept constant, the oxygen outlet flow rate was varied to examine the relationship between oxygen concentration and oxygen recovery rate and flow rate. The increase or decrease in oxygen recovery rate mainly depends on the processes, parameters, and operations of the oxygen production system, and has little to do with the inlet flow rate. Key components such as control valves also have an impact on the oxygen recovery rate; within a certain range, the oxygen recovery rate increases as the instantaneous flow rate of the valve increases. 6. To increase the oxygen recovery rate, the following measures can be taken: 1) Determine a reasonable outlet pressure and system pressure ； 2) Select a high-performance adsorbent ； 3) Optimize the adsorption process of the pressure swing adsorption oxygen generation unit: such as adopting a uniform pressure process at both the top and bottom, and optimizing the backflow pipelines ； 4) Improve the performance of key components such as control valves, etc ； 5) Increase the oxygen flow rate and reduce the required oxygen concentration.

I ask the original poster: generally, what is the recovery rate of pressure swing adsorption oxygen production?

It varies depending on the process and the type of molecular sieve; as far as I know, it’s between 25% and 50%. There may be manufacturers that achieve higher recovery rates, as well as different types of molecular sieves. What I’m referring to are merely ordinary gas treatment manufacturers and the commonly used molecular sieves. I share these humble insights. If you have information on this topic as well as details regarding the oxygen production process, feel free to share it. This post was last edited by c4a on 2008-1-30 12:15]