Discussion on One of the 5 New Urea Technologies Series (UTI Urine Tower Technology)
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On January 31, 2009, jindin312 reported on the news that “for the first time in the world, 5 technologies were successfully applied in a urea project” (see the Chemical Industry News of January 16). This news is certainly very encouraging for the nitrogen fertilizer industry; if this \"world-leading high-tech technology\" proves to work successfully in actual production, it can be considered a major advancement in urea technology. Regarding these 5 technologies, I believe that most users working with urea are not very familiar with them. Therefore, I suggest that we discuss each of these technologies in detail, based on the information we have, so that we can all gain a deeper understanding of these 5 technologies and work together to improve our knowledge. This post focuses on the first technology: the synthesis tower designed using UTI technology. We welcome everyone to participate actively, with extra rewards for in-depth discussions. This post was last edited by lxq700918 on 2009-2-11 17:50.]
First, I will introduce to you the flow path of various materials within the urea synthesis tower in UTI urea technology as follows: Ammonia and recycled ammonium methanate both enter the tower through the top of the synthesis tower and proceed downward within the coiled tubes, where ammonium methanate is formed; at the same time, this process provides the heat necessary for the decomposition of ammonium methanate outside the tubes into urea. After exiting the snake tube, the generated methylammonium is converted back into a urea solution from the bottom of the tower, flowing out from the top of the tower. The concentration of the urine exiting the tower is 30%–33%, with a CO2 conversion rate of 75%–77%. Methylammonium, urea, water, CO2, NH3, and other components present in this urine are reduced in pressure to 2.1–2.2 MPa(G) using a pressure reducing valve, and then sent to the medium-pressure decomposition system. The core of UTI tower technology is essentially a heat exchanger located inside the tower. I wonder if there are any manufacturers in China that use this technology, and whether its performance is indeed as good as described Everyone is welcome to discuss. This post was last edited by ymtuegj12 on 2009-2-16 17:28.]
Of the technologies related to UTI urine towers, only the one mentioned in a chemical industry newspaper has been put into production, with output reaching 300,000 tons.
1 A specially designed \"isothermal synthesis tower\" is used, which is equipped with a feed coil that runs through the tower and has an open interior； 2 Starting from the thermal balance of the entire system, 40% of the total CO2 is directly added to the medium-pressure absorption system, where it exchanges heat indirectly with the urea solution; this causes the ammonium carbamate contained in the solution to decompose, and the urea solution is concentrated to 88% ； 3 The treatment of the condensate is carried out using a single hydrolysis stripping tower; the operating pressure of this tower is 0.9 MPa, and the lowest operating temperature is 180°C℃ ； 4 The low content of biuret in urea products improves the quality of urea ； 5 The diameter of the granulation tower is reduced and its height is lowered; air is blown in from the bottom of the tower and drawn out from the center of the top. The urea granulation nozzles are installed between the air extraction point and the tower wall. This \"counterflow design\" increases the cooling efficiency inside the granulation tower by more than twice ； 6 The equipment cost is low; due to the high CO2 conversion rate, the investment in the synthesis tower equipment and the circulation system equipment is reduced. This post was last edited by Fan Zhou Wu Hu on 2009-2-19 01:29.]
A similar technology was used by Dongyang in the ACES21 project of Chuanhua Phase II; it is unknown whether the equipment has been put into operation. This post was last edited by lxq700918 on 2009-2-24 12:59.]