Effect of deionized water as a catalytic terminator on sulfur dioxide content in flue gas
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After the catalyst was put into use, acidic water was used as the quenching agent. The sulfur dioxide content in the flue gas was relatively high; to meet the required standards, a large amount of alkaline solution was needed for neutralization. In order to reduce the sulfur dioxide levels in the flue gas and thus decrease the amount of alkaline solution required for flue gas desulfurization and denitrification, deoxygenated water, demineralized water, and crude gas oil were tried out. Demineralized water is being used currently, but it is not clear what effect it has on the catalyst. Theoretically, could it help reduce the sulfur dioxide content in the flue gas?
Our unit uses quench oil. It is not used during normal operation.
Using acidic water as a terminator will do; it will not increase the sulfur dioxide content in the flue gases. Since catalytic devices all contain sulfur transfer agents, the sulfur dioxide content in the flue gas and the sulfur content of the raw materials are related to the amount of sulfur transfer agent added. It has little to do with using acidic water as a terminator.
This post was last edited by Refiner on 2017-10-31 11:15. Demineralized water has no effect on flue gas.
This post was last edited by Refiner on 2017-10-31 at 11:16. Moderator: 1. The issue mentioned is doubt – since acidic water is used as a terminator, the amount of sulfur dioxide in the flue gas increases! How can you say there’s no impact? Please provide the evidence! 2. Not all catalytic units incorporate sulfur transfer agents; they were initially used to reduce sulfur dioxide in flue gases and transfer it to the products (dry gas, liquefied gas, gasoline), but they were not widely adopted later on. I think everyone knows why!
1 First, it is necessary to determine whether acidic water refers to the raw water itself or the purified water resulting from acidification. If it is purified water with an acidic pH, there should not be a significant impact; no similar phenomena have been observed in other devices either, so further in-depth analysis is needed. If the raw water is acidic, such as that from the oil and gas separator at the top of the catalytic distillation tower or the oil and gas separator at the top of the coking distillation tower, it is necessary to specifically analyze whether this acidic water contains certain special substances (sulfur-containing compounds); otherwise, the phenomenon described by the original poster would not occur. 2 Acidic water is injected into the upper part of the lift column as a quenching agent; it should vaporize rapidly and, after being separated from the reaction gas mixture and catalyst, enter the distillation tower. The source of excessive SO2 emissions in the flue gases lies in the coking process in the regenerator, and it is related to the sulfur content in the coke as well as the manner of coking. On the 3rd floor, the poster asked: “We have been using demineralized water all along – what is the effect?” It is recommended to share.
The total amount of gas injected accounts for 25%. The termination dose is 5%-8%; vaporization occurs, and the resulting steam condenses into acidic water. Most of the sulfur in the raw materials and that in the acidic water returns to the acidic water along with the steam. The catalyst humidity is kept constant; the flue gas to air ratio ranges from 1.02 to 1.05, varying among different units. Although the sulfur content in the feedstock affects the sulfur content in the flue gas, the sulfur content in the catalyst remains essentially unchanged. The sulfur transfer agent I’m referring to is an injection, not a catalyst; it seems that there are now formulations that combine sulfur transfer with passivation in one injection. It’s just my personal opinion; I hope to discuss it with everyone.
The total amount of gas injected accounts for 25%. The termination dose is 5%-8%; vaporization occurs, and the resulting steam condenses into acidic water. Most of the sulfur in the raw materials and that in the acidic water returns to the acidic water along with the steam. The catalyst humidity is kept constant; the flue gas to air ratio ranges from 1.02 to 1.05, varying among different units. Although the sulfur content in the feedstock affects the sulfur content in the flue gas, the sulfur content in the catalyst remains essentially unchanged. The sulfur transfer agent I’m referring to is an injection, not a catalyst; it seems that there are now formulations that combine sulfur transfer with passivation in one injection. It’s just my personal opinion; I hope to discuss it with everyone.
After using it for some time, judging from the amount of alkali required for flue gas desulfurization and denitrification, there is no significant difference between demineralized water and acidic water. Perhaps the demineralized water has been used for a relatively short period of time; however, compared to the acidic water, the cost of demineralized water is indeed too high, so it is not suitable – we should switch back to using acidic water
Give it a try – use purified water with an acidic pH; this can **reduce costs, and I think the results will improve.** Additionally, it is recommended to analyze acidic water to determine whether, in addition to hydrogen sulfide, there are also some organic sulfur compounds, such as thiols, thioethers, and other larger organic molecules. Logically, there shouldn’t be any; through acidic water stripping, hydrogen sulfide is obtained at the top of the tower, while purified water is obtained at the bottom. At the same time, it is also recommended to analyze the purified water to determine whether there are still some organic sulfur compounds, such as thiols, thioethers, and other large-molecule organic substances.
Have there been more devices using sulfur transfer agents in recent years?