In the lignite upgrading process, how are coke powder and tar separated from the gas purification system?
Thread Content
In the gas purification system, there is a large amount of dust containing 20–40% tar in the cyclones and double vertical tubes; this dust is in a solid, muddy form with very high viscosity. I’d like to ask everyone if they have any good methods for recovering tar from this dust. If there is any relevant information or references available, please feel free to share them. Thank you
Heating is used in conjunction with a centrifuge to remove slag; high-speed centrifuges can be considered for this purpose. If you’re interested, feel free to contact me.
Can the high content of powdered coke in tar be removed by centrifugation? Are there any applications? How is it working?
An electric tar catcher can be used, and it works very well; feel free to contact me if you’re interested. QQ: 395159906 TEL: 13995763512
Firstly, high-speed centrifuges yield poor results when the viscosity of the fluid is too high; in cases such as a mixture of coal tar and dust, the yield is extremely low, resulting in significant waste； Secondly, electrostatic capture technology is also not suitable for fluids with high viscosity; moreover, coal tar has strong adhesiveness, which causes the electrostatic capture probes to stick together and reduces efficiency ； Finally, if the fluidity of coal tar is good, a filter with a screen can be used; referring to the pre-treatment process in the FTH workshop of Shenmu Fuyou Energy Technology Co., Ltd., this approach can meet the requirements for long-term operation.
Due to the high viscosity and poor flowability of dust-containing tar or even asphalt, filtration methods tend to get clogged very quickly; in the case of electrostatic capture, both the electrodes and probes are quickly covered with a thick layer of residue, preventing the separation equipment from operating continuously for extended periods of time. Shenmu Company reported that they initially used filtration, but it led to blockages almost every day, preventing continuous operation and incurring high costs ； Later, pre-cooling + electrostatic precipitator was also considered, but continuous operation proved unstable; the electrostatic precipitator had to be shut down within less than two weeks, making it impossible to operate continuously for extended periods ； Later, a cyclone separator with vertical tubes designed by a certain university was adopted; even after operating continuously for nearly a month, a large amount of sludge buildup formed on the outer wall of the vertical tubes, forcing the system to be shut down and the buildup removed using steam and pneumatic hammers. Their technical team visited us before the New Year, hoping to draw on our successful technical experience with the crude gas purification separator in Shenhua Ningmei coal powder gasification units. You can visit the link http://bbs.hcbbs.com/thread-1354813-1-2.html on the Haichuan Chemical Forum to learn more about our separation technologies. We hope to be able to help customers facing similar problems.