Flue gas desulfurization and flue gas dust removal types for catalytic cracking units! !
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The bag filters used for wet flue gas desulfurization with calcium-sodium double-alkali in our catalytic units suffer from severe caking; the new bags get blocked, corroded, and damaged after a short time, resulting in an excessive pressure difference in the filters that forces them to be shut down. What type of dust collector do everyone use in their catalytic devices, and what is the performance like?
Where is the calcium-sodium double-alkali wet flue gas desulfurization process from? At present, the most widely used process for catalytic flue gas desulfurization is Berg’s EDV desulfurization method; there are roughly 60 such facilities in China at the moment.
The last edit to this post was made by luoli519 on 2018-5-16 at 17:33. In the FCCU flue gas desulfurization systems, Exxon’s WGS process and DuPont Bellerophon’s EDV process are widely used both domestically and internationally, with each accounting for roughly half of the market share； There are not many process units that use the calcium-sodium double-alkali method, the calcium method, or the ammonia method. In the flue gas desulfurization system of FCCU, bag filter dust removal is not highly recommended regardless of the desulfurization process used. Due to the wet flue gas desulfurization process in FCCUs, the flue gas contains numerous salt-containing droplets, mist, and particulate aggregates, which can easily clog the separation elements that operate on a interception basis, such as the filter bag elements. Furthermore, the particulate aggregates that accumulate on the internal components of the bag filter include salt crystalline deposits, viscous gypsum, as well as catalyst particles; they have strong adhesion, result in high operating pressure drops, and are difficult to remove during regeneration. Recently, the refining and chemical enterprises under CNPC have upgraded their existing FCCU flue gas desulfurization systems as well as the sulfur exhaust gas incineration flue gas desulfurization systems that use the WGS process, by installing specialized anti-clogging vane mist eliminators. This upgrade has successfully resolved the environmental issues related to rain and dust precipitation from the scrubber towers of these systems. In particular, it has addressed the problem encountered by enterprises in the northern regions during winter, when rain from the scrubber towers caused thick layers of ice to form on the ground around the facilities, on pipe racks and ductwork, and on rooftops, leading to risks of injuries to personnel and damage to equipment and instruments. The anti-clogging special feather-type mist eliminator used in wet flue gas desulfurization towers boasts significant performance advantages: strong resistance to clogging, low operating pressure over long periods, high separation efficiency, a wide range of operational flexibility, and the need for few spare parts, resulting in minimal maintenance requirements. Last year, the flue gas desulfurization scrubber of CNPC Wushihua’s FCCU was successfully upgraded to address potential risks by installing vane mist eliminators in its flue gas desulfurization system ； The Dushanzi Petrochemical Plant of CNPC installed vane mist eliminators in the flue gas combustion and desulfurization systems of two WGS process sulfur plants the year before last, to achieve efficient separation of gas, liquid, and solids from the flue gas coming out of the scrubbers; the plants have been operating continuously, efficiently, and stably to this day. Many companies troubled by this issue sent personnel to the installation sites of the aforementioned companies for on-site inspections; after retrieving data and images from the DCS control room for verification, they decided to upgrade their existing installations by using vane mist eliminators.
Everyone can directly search for the link https://bbs.hcbbs.com/thread-1944683-1-1.html on the Haichuan Chemical Industry Forum to learn more about the operation of feather-leaf mist eliminators in the flue gas scrubbing towers of refining and chemical processing systems, as well as the comparative data related to them.
The sodium-calcium double-alkali desulfurization technology has been almost phased out in boilers nowadays; it is difficult to regenerate, and its operation requires an alkaline environment. In such conditions, scaling problems tend to occur in the desulfurization system, as well as blockages in the demisters. Since the sodium-calcium substitution reaction is itself a theoretical reaction, it is difficult to ensure its complete completion; as a result, the calcium introduced into the desulfurization tower forms scale under alkaline conditions.
Bag filter dust removal is available in all the catalytic units of Sinochem. Are you from Sinochem?