Urea hydrolysis issue
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When designing a urea hydrolysis tower, what is the relationship between the urea concentration in the ammonia solution, as well as the residence time in the hydrolysis tower, operating pressure, and temperature? For example, if the urea content in the ammonium carbamate solution is 2.0%, what should be the residence time, operating pressure, and temperature in the hydrolysis tower? The Stamicellase hydrolysis process is proposed to be used. Desorption system design capacity: 30 m3/h. Diameter of hydrolysis tower: 1400mm ； Tower height: 28m. This post was last edited by prendent on 2009-3-31 11:22]
The client needs to explain what kind of hydrolysis process you use, so that we can provide you with relevant references and suggestions; after all, different processes involve different temperatures, pressures, and residence times in terms of design. For example: Snam hydrolysis process: 235℃ ； 3.4Mpa, Stamicell hydrolysis process: 195℃ ； 2.0 Mpa, and the structure of the hydrolysis tower is different as well, resulting in different residence times. This post was last edited by Fan Zhou Wu Hu on 2009-3-31 01:51.]
As stated by the poster, under the conditions of the hydrolysis tower provided by the Stamicarbon process, and while ensuring the appropriate hydrolysis temperature, the residence time of the solution is about 1 hour; even when the urea content reaches 2.3%, the design specifications can still be met. To account for the entire desorption-hydrolysis system, generally there are no issues with the hydrolysis tower; the key lies in the desorption tower. In domestic urea production plants, it is difficult to achieve the design specifications for the effluent from the desorption tower (with NH3 and Ur levels below 5 ppm), and the problem lies in the desorption tower itself. As long as the desorption tower is properly designed, the purified water produced by the hydrolysis-desorption system will generally meet the design requirements. Special care must be taken when using a packed tower as the internal component of the desorption tower; it is essential to consult the design team thoroughly.
Recently, a newly established company with 18.30 years of experience conducted research specifically on the issue of the desorption-hydrolysis system not meeting the required standards. It consulted several manufacturers, design firms, and universities, and ultimately identified the problem; the original design was then optimized, which will certainly help avoid unnecessary detours and reduce costs associated with technical upgrades.
Optimizations of processes and equipment: 1. Without increasing the original design diameter and height of the tower, high-efficiency and high-flux desorption tower internals are selected. II. Try to increase the temperature of the hydrolysis tower to enhance its efficiency. This post was last edited by lxq700918 on 2009-4-1 19:45.]