Relationship between sulfur content in catalytic feedstock and diesel pour point
Thread Content
In the Q&A on catalytic cracking technology by Marbowen, regarding the impact of sulfur content in feedstocks on the quality of catalytic cracking products, it is stated that the freezing point of products derived from low-sulfur feedstocks is higher than that of products derived from sulfur-containing feedstocks. In fact, that’s indeed the case. Taking diesel as an example, the sulfur content in the raw materials used in our catalytic system is lower than that in two-catalyst systems; as a result, the freezing point of their diesel is much lower than ours. My question is, what causes this situation? Is it due to the different sulfur content in the products? Is it because the sulfur content in the raw materials varies, which leads to an increase or decrease in the amount of gums or other substances in the product? Any other reasons you can think of? Furthermore, what is the reason why this substance causes the freezing point to rise or fall? That is, how does it change the structure to cause a change in the freezing point? This post was last edited by mjl25mp6 on 2008-1-13 13:50.]
Many people have come in to take a look, but none have left a single word; it seems that there’s no easy answer to this question for now. How about this: let’s see if any of Hai Chuan’s friends can ask this question to your other friends, in the hope of getting an answer from Hai Chuan!
Personal opinion: Could it be that the effect of sulfur on the catalyst is causing a decline in activity and selectivity, a reduction in cracking strength, weak isomerization and aromatization reactions, low conversion rates of heavier aromatics and naphthenes in the feedstock, an increase in components such as n-normal alkanes in diesel, and an elevation in the freezing point?
Sulfur has a sulfiding effect on catalytic molecular sieve catalysts; after being sulfided, these catalysts become more active, which is why the situation described by the original poster occurs.