How many types of urea towers are there??
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In one book, I found three types of urea synthesis towers: those using CO2 for stripping, those using a fully recirculating solution-based modified C-process for urea synthesis, and those using NH3 for stripping. I am working on my graduation project, and the requirements state that urea should be produced using a process based on fully recirculating aqueous solutions. Does the term “fully recirculating aqueous solutions” refer to the “fully recirculating solution-based modified C-process” mentioned in the book? Thank you!! I also want to know what exactly “fully recirculating aqueous solutions” means. I haven’t gathered enough information yet; thank you again for your help.
Full circulation of the aqueous solution means that all the ammonia and carbon dioxide that have not been converted into urea are recovered and reused in the production process. Full circulation of aqueous solution and the improved C-process with full circulation of solution are two different processes; both are used for producing urea, but they differ from each other.
1. The “full circulation of aqueous solution method” is not the “improved C method with full solution circulation”. 2. During the synthesis of urea, it is not possible for the raw materials ammonia and carbon dioxide to be completely converted into urea; this leads to the issue of separating, recovering, and recycling the unreacted substances. Different methods for separating and recovering these unreacted substances result in various urea production processes. Such as: CO2 stripping method, NH3 stripping method, full aqueous solution circulation method, improved C method with full aqueous solution circulation, etc. 3. Due to differences in various production processes, the operating and design pressures and temperatures of urea synthesis towers also vary ； The structure of the urea synthesis tower also differs; in the aqueous solution full-circulation method, the three reactants used in the urea synthesis tower enter from the bottom, while the gas and liquid exit from the top.