How to control SOx emissions from catalytic cracking flue gas to meet standards?

When it comes to sulfur management in refineries, I think it’s better to consider everything comprehensively. Don’t treat your head but forget your body? . . . . The flue gas complies with the air pollution emission standards. If the flue gas fails to meet the standards, it will be installed in a flue gas desulfurization device. I think this approach is feasible. It is better than transferring sulfur into the product for treatment, and it can also reduce the cost of hydrotreating. . . . :lol

It seems that the current catalytic devices are not equipped with flue gas desulfurization. I wonder if what I said is accurate? Some domestic devices use sulfur transfer agents to transfer the sulfur in the flue gas to the oil and gas on the reaction side. It exists in the form of H2S and is recovered in the form of sulfur by the sulfur recovery device through dry gas desulfurization. It is not transferred to the liquid product as mentioned on the second floor!

There is currently no good treatment method, and the effect of adding a sulfur transfer agent is not obvious.

As the processed raw oil becomes heavier and heavier, the content of sulfur, nitrogen oxides and heavy metals also increases, which will inevitably increase the content of sulfur, nitrogen oxides and heavy metals in the subsequent flue gas, dry gas, gasoline and diesel. Investing in efficient cyclone separators can reduce SOx content, but this investment cost * * Increase, so that some factories do not invest enough and save this cost. The SOx content in flue gas does not meet the standard.

Take a look at the post - it's very early - correct me, now in China only Lanzhou Petrochemical and Sichuan Petrochemical have catalytic flue gas desulfurization devices, Lanzhou is in operation and Sichuan is under construction - I am involved in them----

At present, there are many ways to solve the problem of delayed emission compliance. It mainly depends on which indicators exceed the emission limit requirements, usually SO2, dust and NOx. Some devices of NOx do not exceed the standard, but most devices emit SO2 and dust. In addition to concentration, don’t forget that there is also the absolute amount (total amount). Main methods to solve smoke emission problems: 1 Raw material pretreatment is not entirely to solve the problem of flue gas emissions, but more importantly to solve the problem of product quality. In addition, it cannot solve the problem of dust emission. 2 Adding desulfurization aids can solve the SO2 emission problem in the flue gas to a certain extent, but it cannot completely solve the flue gas emission problem when the SO2 concentration in the flue gas is high. 3. The addition of flue gas desulfurization facilities (generally using the alkali method) is to completely solve the problem of flue gas SO2 emissions, but in fact most of it is pollution transfer, transferring SO2 in flue gas to sewage, and does not realize the true removal of SO2. At present, the cost of adding flue gas desulfurization facilities is high, with high investment and high alkali consumption. None of them is a good solution. If a combination of the above technologies is used, the discharge of sweaty salty sewage can be reduced, and more consideration and analysis will be made from the perspective of economic benefits.

I personally believe that flue gas desulfurization technology is very mature and can achieve desulfurization standards. The main reason is that the investment is large and it is completely an environmentally friendly project that many units cannot meet. As environmental protection requirements become increasingly stringent, this project will receive more and more attention.

WEPEC, catalytic flue gas desulfurization, uses alkaline washing and absorption, and the absorbent (washing liquid) is Mg(OH)2, which has also been put into operation. Beihai Petrochemical's catalytic flue gas desulfurization has been put into operation at the beginning of this year. The absorbent (washing liquid) is Na(OH)2. However, the SO2 concentration in the Beihai catalytic flue gas is very high and the alkali consumption is large. Flue gas desulfurization technology is relatively mature in power plants, and most of them use the calcium method. However, catalytic cracking flue gas desulfurization and denitrification are taking off in China. Due to the long operating cycle of the catalytic cracking unit, the requirements for flue gas desulfurization facilities are also high. This is the main problem. Flue gas desulfurization facilities and the catalytic cracking unit are generally required to operate simultaneously (continuous operation for more than 3 years). In the United States, most catalytic flue gas desulfurization uses the sodium method (NaOH). In China, most of them currently use the sodium method. In power plant flue gas desulfurization, it can be said that a hundred flowers are blooming, including calcium method, sodium method, magnesium method, double alkali method, ammonia method, etc.

This post was last edited by biac on 2012-12-25 22:09. The pressure drop of catalytic flue gas desulfurization is very important. How to ensure that it does not affect the hood, waste heat boiler, imported technology with the lowest pressure drop, and solve the discharge of high-salt wastewater? Please send an email to xjt9999@126.com