Can the absorption stabilization system enable pressure reduction operations in the desorption tower?
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As the title suggests, is it possible to achieve this? At a top pressure of 0.3 MPa in the desorption tower, what temperature should the tower top be maintained at? Technical Summary: This invention discloses a method for reducing the energy consumption of absorption stabilization systems. The key aspects of this method involve reducing the operating pressure at the top of the desorption tower from the current level of 1.2 MPag to 0.25–0.4 MPag, and reducing the operating pressure at the top of the stabilization tower from 1.15 MPag to 0.3–0.4 MPag. Additionally, the gas coming from the top of the desorption tower is directed to the inlet of the first stage of the rich gas compressor; a compressor is also installed at the top of the stabilization tower to ensure that LPG liquefies at room temperature. Since the gas at the top of the desorption tower contains virtually no C3/C4, the reflux flow rate from the stabilizer tower decreases significantly; as a result, the flow rates of these two gases are low, which means that the compression power consumption increases only slightly. The reverse swing margin of the rich gas compressor can be utilized, and the compressor for the gas at the top of the stabilizer tower employs a single-stage electric drive system and is installed on the tower’s top platform. In the desorption tower and the stabilization tower, the pressure reduction operation not only reduces the heating load by nearly half but also causes a significant drop in the temperature at the bottom of the towers; as a result, hot water and 1.0 MPa steam are used as heat sources instead, eliminating the need for an intermediate reboiler in the desorption tower. Technical R&D personnel: Li Guoqing; Cai Chuxuan; Zhang Jialong. Protected technology user: South China University of Technology. Document number: 201710558678. Date of technical R&D: 2017.07.11. Date of technology publication: 2017.10.03
I found a patent online. I would like to ask the experts here: if this technology is feasible, what temperature should be set at the top of the desorption tower to ensure that the tower does not experience excessive desorption?
Search to see which company uses it
I don’t think it’s very realistic. First, with a catalyst amount of 1 million, the amount of gas released is around 6,000, while the pressure at the inlet of the compressor is around 20,000. The amount of gas released is one-third of the amount of rich gas; who could design a compressor with such high pressure? The amount of compressed steam wasted must be just as much as the amount saved. Second, why is the desorption tower operated at high pressure? It is necessary to ensure the liquefaction of C3 and C4 even under conditions of ethane removal. At what temperature does liquefied gas liquefy at 0.3 MPa? Is it below zero? The stabilizer tower is the same as above.
I would like to ask how the additional cost of the compressor is calculated?
I also think it’s unlikely, but no relevant data could be found. If it is an absolute pressure of 0.4, what temperature is required at the top of the desorption tower? It can both desorb carbon 2 and retain carbon 3, 4.
I’m not quite sure about this. No relevant information could be found.
Is there any refinery that applies such technology?
Low-temperature absorption can enable pressure reduction operations.
Thank you. Could you please provide relevant data or application examples?