Terminators include crude gasoline, light dirty oil, acidic water, etc. What are the differences between them and what are the selection principles?
Thread Content
Terminators include crude gasoline, light dirty oil, acidic water, etc. What are the differences between them and what are the selection principles?
http://bbs.hcbbs.com/viewthread.php?tid=75465&highlight=%D6%D5%D6%B9%BC%C1
The purpose of using a terminator is to lower the reaction temperature at the outlet of the riser to shorten the reaction time. The principle of choosing a terminator is that it can vaporize quickly to absorb as much heat as possible. Generally, crude gasoline is used, which is easy to adjust and does not need to cooperate with other departments. If straight-run oil or light dirty oil is available, it can be used first, which can increase economic benefits. Using straight-run oil can also reduce the olefin content of gasoline. As for acidic water, we have never used it. It is estimated that it will increase the load of the stripping device and may also cause thermal collapse of the catalyst.
Large factories use crude gasoline, while small factories use acidic water. The main reason is that their latent heat of vaporization is different.
If there are heavy chemicals, use heavy chemicals. If not, use crude gasoline. Their effects should be similar. We have also been using acidic water. The heat absorbed by the water should be more. In addition, acidic water also has atomized steam. The temperature of the riser catalyst is about 510 degrees, so it should not have a big impact on the catalyst.
In addition to endothermic cooling to terminate the reaction, injecting acidic water also has another reason to improve the acidic active center of the catalyst. As we all know, the method for measuring the activity of the catalyst is to use D+L measurement to measure the consumed KOH index. Ensuring the acidic active center of the catalyst ensures the activity of the catalyst. It has a certain positive effect on the aging of the catalyst.
We have been using acidic water. On the one hand, it absorbs a lot of heat, and on the other hand, it can reduce the coking of the riser. This is what we have figured out in production and has no theoretical basis.
The use of gasoline is beneficial to increase the production of liquefied gas and propylene；
Generally, crude gasoline or acidic water is used. Our factory uses crude gasoline.