37- Solutions to frequent clogging of tar and dust in the gas supply filtration separator for the coke oven gas-to-LNG project
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This post was last edited by luoli519 on 2020-1-4 at 11:27. In the vast majority of domestic and international LNG projects powered by coke oven gas, multiple large-scale coke oven gas tanks located in tank farms are used to store this gas, which is then supplied as a fuel source to the main facilities of the project. The coke oven gas coming out of the gas holder needs to have the liquid droplets and foam present in it removed first in a coke tower; after this pre-treatment, the gas is sent to a filtration and separation unit located at the boundary of the main plant area for further separation, before being supplied to the main plant area. However, this filtration separator located at the boundary of the main equipment area often encounters problems: either its separation efficiency is poor, or the equipment gets clogged resulting in low gas supply, leading to unstable operation. The amount of maintenance work required is high, and the operational and maintenance costs remain elevated, making it a common issue and a major concern for the project. Many owners have requested NOVEL to utilize its patented high-temperature dust- and tar-containing coke oven gas/pyrolysis gas/low-rank coal upgrading gas dust removal and separation system to upgrade the existing separation process technology. Here, we also invite colleagues from domestic and international facilities that produce LNG using coke oven gas as the feed gas to share solutions based on their own operational experiences.
A technical supervisor at a plant that produces LNG from coke oven gas told NOVEL that their original process involved installing 4 or 5 coke towers with considerable diameter and height on the outlet pipelines of the gas holder cluster in the tank farm. However, the frequency of dust and tar clogging the filtration separators in the treated coke oven gas did not decrease significantly, which did not bring any relief to them.
The dust, tar, and naphthalene mixture carried in coke oven gas clogs the filters of the separation units, resulting in a high frequency of filter replacements. This imposes a heavy workload and high physical strain on the technicians and workers involved in maintenance tasks. Workers, technical engineers, and section supervisors are all reluctant to work on this task, as it proves very troublesome for them.
The workshop supervisor told me that their factory has strict cost assessment rules, which are linked to revenue. His technicians and workers, seeing that replacing so many filter elements resulted in high operating costs, tried to reuse the filter elements that were barely deformed by boiling them in alkali and rinsing them with steam ； As a result, a pressure drop alarm was triggered, the gas production volume was low, and the downstream processes did not receive sufficient supply; therefore, attempts to regenerate and reuse the filter elements had to be given up.
The workshop supervisor also told NOVEL that, in order to extend the continuous operation period of the boundary zone coke oven gas filtration separator, the workshop resorted to a less optimal solution by replacing the filter elements with a precision of 50 mesh with ones having a precision of 30 mesh; however, this approach did not yield significant results, and the operation period of the filter was not extended noticeably. It can be seen how severe the blockage caused by dust, tar, and naphthalene carried in coke oven gas is.
Let’s take a look at the operational data of the coke gas filtration and separation unit in an enterprise that produces LNG from coke gas: 1. Coke gas treatment capacity: 70,000 Nm^3/h; 2. Pressure: 6 kPa； 3. Temperature: 30°C.
The gas separator you mentioned, which has a filtering function without the need to replace the filter elements, what type of technology does it use for gas filtration and separation? I’d like to hear the details.
This post was last edited by luoli519 on 2020-5-9 at 11:04. Bag filtration, Y-type filtration, cyclone plate separation, and pre-coagulation plus cyclone plate separation are all covered; it is mainly applicable to air media such as that used in trucks and air compressors under stable operating conditions. The first two methods rely on filter bag or screen internals, representing traditional barrier filtration, while the latter two use internals placed within the flow channel to achieve separation through fluid dynamics. Hydrodynamic separation technology is quite suitable for the target operating conditions. You can visit the company’s official website at www.novelseparationtech.com to learn more about its dynamic separation technologies and equipment, as well as their applications in various industries such as petroleum and petrochemicals, coal chemical processing, metallurgical coking, and natural gas processing and transportation.
Could you send me a copy of Xue* Xue* as well? yangtaibao2055@163.com. Thank you.
This post was last edited by luoli519 on 2016-10-18 at 18:07. Is Zhijie an agent? The translation is incredibly painful to read.
Let’s take a look at the difference between the design values provided by the design agency and the actual values obtained from the company’s operations: Tar, H2, CO, CO2, N2, O2, C2H6, CH4. The designed composition of the feed gas is 55.61, 9.84, 3.49, 5.43, 0.53, 2, and 23.05 respectively; while the average values obtained from sampling analyses are 28.06, 61.25, 9.99, 3.18, 4.23, 0.18, 0.94, and 21.26 respectively