How to recover propylene decarboxylation vapor more economically
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In our facility, the carbon propyl decarboxylation flash vapor used to be sent directly to the inlet of the absorption tower after pressurization； To address the issue of refined ammonia water, it is planned to use a carbonization tower to produce ammonium carbonate as a solution. In the past, we sent refined ammonia solution to urea desorption for desorption. Please have the sailors discuss which method is more cost-effective.
This post was last edited by 654262293 on 2010-8-20 at 12:47. Our old factory uses the method of sending flash vapor to the ammonium carbonate production unit to manufacture ammonium carbonate; when that unit stops operating, the flash vapor is sent to the inlet of the first stage of the compressor for recovery. This should be more reasonable. Firstly, the dilute ammonia water obtained from ammonia recovery and the flash vapor from the decarburization unit are fully utilized to produce ammonium carbonate products. Additionally, the previous method of returning these substances to the inlet of the absorption tower increased the load on the decarburization system. As our plant expanded its production capacity from 100,000 tons of ammonia per year to 150,000 tons per year, the CO2 content in the purified gas from decarburization was high; the problem was resolved only after replacing the water coolers with ammonia coolers.
As a supplementary note, our factory does not have any carbonization equipment at the moment; the original carbonization facilities were all removed when urea production started in 1997. Now, everything related to ammonium carbonate production has to start from scratch.
Reply to 3# Yan Qiusheng: Pressure swing adsorption is currently being used for the purification and recovery of flash vapor – should this option be considered?
This post was last edited by 654262293 on 2010-8-20 at 12:46. In principle, the most reasonable method for reusing the decarbonization flash vapor is to use it in the production of ammonium carbonate; this not only purifies the flash vapor but also deals with the excess ammonia, enabling the production of ammonium carbonate. If the ammonium carbonate plant is rebuilt, that’s a different matter. Can ammonia water be sent to the urea hydrolysis unit for recovery, and the flash vapor be recovered using pressure swing adsorption?
Our factory recovers it through purification via pressure swing adsorption
Reply to 1# Yan Qiusheng: Our plant has two ammonia synthesis systems; one is used for producing ammonium carbonate through carbonation, while the other is used for flash distillation to recover hydrogen and nitrogen, which are then sent to the compressors and into the main pipeline
For our company, a 10,000 cubic meter pressure swing adsorption unit is sufficient
Currently, pressure swing adsorption is the trend in carbon removal processes; carbon-propane-based carbon removal is rarely used. Although the investment cost for pressure swing adsorption is relatively high, its operating costs are low
Part of the flash vapor from our plant is sent to the carbonization unit, while another part is sent to pressure swing adsorption. The product gas is fed into the inlet of the first stage of the compressor, and the copper-washed ammonia is used in the urea decomposition process. However, for the production of ammonia in the carbonization unit, ammonia gas from the outlet of the synthetic ammonia cooling system is utilized; this helps to reduce the load on the refrigeration machines during summer