Hydrogen production in synthetic ammonia
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May I ask everyone, in the process of purifying hydrogen using PSA in ammonia synthesis, there are set limits for the final charging pressure and the reverse discharge pressure in pressure swing adsorption. Is this overall adjustment done at your plant? It still stays stopped after the trial run proceeds normally, whether operating at full capacity or not. Thank you, let’s exchange ideas.
The adsorption pressure is usually fixed; there is a minimum value set for the pressure at the start of reverse operation, mainly to prevent impurities from penetrating the bed layer. This value is determined during system calibration, and it remains unchanged as long as the adsorption pressure stays the same.
Generally, final charging is carried out using the product gas; if the final pressure is not sufficient, it indicates that either the punching speed is too low or the punching time is insufficient. Reverse playback also has a reverse playback rate and reverse playback time, which are generally not adjusted unless the manufacturing process needs to be changed significantly. In particular, the charge and discharge rate is generally not adjusted
Do I not need to do anything after the trial run and once normal production starts? Under conditions such as reduced production volume and lower production pressure, we haven’t made any changes here either; let me take a look at what others have done.
Are there any process specifications for vacuum level?
In my previous process, the reverse playback value was set at 0.02. Generally, there are indicators provided by the manufacturer. A vacuum is generally achieved by pumping out air to reach a vacuum state
PSA, whose product are you using?
One set from Huaxi, one set from Sichuan Tianren
Yes, I mean, is there a specification for the exact vacuum pressure?
I found a set of operating procedures and pumped the vacuum to -0.08. I’ve never used VPSA before