In ammonia plants that use the hydroformylation process, what impact does methanol production have on the ammonia catalysts?
Thread Content
Our company is an ammonia plant that uses the methanol-to-ammonia process. Previously, the methanol production system consisted of a short &600 tower (non-standard) in series with a standard &600 tower; last year we replaced the short &600 tower with a standard &800 tower. Since its installation, whenever the load increases or the catalyst temperature rises, the ammonia synthesis catalyst reaction suffers – pressure goes up, the hot spots shift downward, and it’s somewhat similar to catalyst poisoning. I would like to ask those who are familiar with this situation what the reasons might be and what solutions exist
I’m not sure what refining process your factory uses. If it’s the copper washing process, any issues with the dihydroxylation step should be evident in that stage; if it’s the methanation process, I suggest looking for causes in other areas as well, not just in the dihydroxylation step
Judging from the symptoms, it is a mild case of poisoning. It is necessary to focus on analyzing the CO+CO2 content in the gas after alcohol treatment to determine whether there are any differences compared to previous measurements. Additionally, the following should be taken into account: 1. The operating condition of the refining system. 2. The location of the synthetic make-up gas – whether it facilitates the slight washing of the make-up gas. 3. Check whether the amount of ammonia in the make-up gas washing liquid is sufficient to ensure an effective washing effect.
We use the copper washing process for refining, and there are no issues with trace analysis (CO+CO2). The location where gas is added remains unchanged from before; we are investigating whether there might be any side reactions involving methanol.
If the separation efficiency in the methanol system is poor, it should first be reflected in the composition of the copper melt, rather than being carried over to the ammonia synthesis process. It is recommended to check whether there is a direct gas leakage issue with the compressor, which might cause a slight excess in pressure that isn’t detected; in such cases, the gas from the tower can be connected for direct measurement.