57- Discussion on the upgrade of the separation technology for off-gases in the oxidation unit of benzene-based **production facilities using feather leaf separators
Thread Content
This post was last edited by luoli519 on 2023-10-2 at 15:41. Currently, there are over a dozen facilities in China that use petrochemical benzene as raw material for production. The oxidation unit is one of the core units of the plant, as it is related to the product yield and the safe operation of the plant. The oxidation unit needs to discharge the accumulated inert gases through vent gas, while separating and recovering the liquid-form raw materials, semi-finished products, and target products carried in the vent gas requires the use of a gas-liquid separator. According to statistics, in the more than a dozen oxidation unit vent gas-liquid separators that have been built, wire mesh demisters are used as vent gas separators in the vast majority of cases. These separators exhibit unstable separation efficiency, high operating pressure drops, are prone to clogging, and lead to frequent unplanned shutdowns. The client requires the use of vane-separated internals to make use of the existing wire mesh demister shell, while also carrying out a technical upgrade of the wire mesh internals. Friends who work with such devices are invited to discuss based on their own experiences.
The production of **by domestic enterprises from refined benzene through processes such as hydrogenation, oxidation, and hydration began in the second half of the last century. Initially, there were few organizations involved in the process design for this device, and the process technologies and equipment used remained at the level of the 1980s and 1990s; such process technologies were essentially copies of existing ones.
Among the current dozen or so units in operation, apart from the problem of separating alkanols from waste alkaline solutions discussed in other technical articles, there is also the issue of separating gas from liquid in the off-gases from the oxidation unit. The large amount of raw material and finished product droplets carried by the bleed gas results in high pressure drops and clogging of the screen internals, leading to frequent unplanned shutdowns. This results in unsatisfactory production efficiency and operating costs, a problem that plagues the owners greatly.
In recent years, many technical personnel who were previously involved in the production and operation management of equipment have left their original companies to join design firms, where they use their practical production experience to carry out technical improvements and upgrades to existing processes. There are also some such factors contributing to the upgrade of the gas-liquid separator in the oxidation unit’s off-gas treatment system.
This post was last edited by luoli519 on 2019-12-25 at 16:01. The image below shows the original design of the wire mesh separator used for vent gas treatment in the oxidation unit – a system that has caused considerable trouble to the production management staff at a certain caprolactam manufacturing company
The aforementioned screen separator was technically designed by a design firm within the original system, and there are many similar devices in China as well.
The last edit to this post was made by luoli519 on 2016-11-27 at 18:21. The operating conditions for the pneumatic mesh separator are as follows: 1. Composition: oxygen, nitrogen, and other organic gases； 2、OP: 1Barg ； 3、OT:196℃ ； 4. Gas flow rate: 4000.5 Am^3/h; 5. Gas density: 4.09 kg/m^3; 6. Gas viscosity: 0.021 cp ； 7. Liquid phase flow rate: 2000 kg/h ； 8. Liquid phase density: 855.88 kg/m^3; 9. Liquid phase viscosity: 0.4 cp.
Original design parameters: 1. DP: 280kPag; 2. DT: 210℃； 3. Operating pressure drop: not exceeding 50 mBar ； 4. Material: S30408. Did the design team fail to specify clear requirements for separation efficiency? !
This post was last edited by luoli519 on 2023-10-2 at 15:42. After consulting various sources, the owner decided to upgrade the existing screen separator by adopting the G50 patented technology for vane separation. So, what are the technical advantages of the G50 type vane separation patented technology components over traditional wire mesh demisters?
This post was last edited by luoli519 on 2023-10-2 at 15:42. The following document provides a comparison from various aspects such as technical level, separation efficiency, operating pressure drop, operational flexibility, continuous operation cycle, cost, operating expenses, and social environmental benefits:
This post was last edited by luoli519 on 2023-10-2 at 15:43. It should also be noted that by reusing the existing separator housing and upgrading the original mesh internals with G50-type vane separation patented technology, the processing capacity can be increased by 30%~50% or even more, while operational flexibility is greatly enhanced. For capacity expansion within the 150% range, there is no need to invest in this separator anymore.