The role of delayed coking in refineries

Delayed coking units and catalytic cracking units are the two main types of units in oil refining plants. Compared to each other, catalytic units are much more delicate than coking units. Delayed coking units are regarded as waste treatment facilities, as they can handle oils with very poor quality. Catalytic units are more complex to operate than coking units, but coking units are more dangerous.

Delayed coking is a relatively mature, advanced processing technology used to treat vacuum residue or catalytic slurry, especially low-quality residues. Delayed coking units require low investment and operating costs; their process technology is well-developed, they offer a high degree of conversion, and they can utilize a wide range of feedstocks, including asphalt and oil sands. Since the 1990s, due to the rapid increase in the processing volume of sulfur-containing crude oil in China and the growing demand for ethylene feedstock, coking units have become increasingly important in the processing of heavy oils in that country. Environmental regulations have imposed certain restrictions on the amount of catalytic cracking that can be used, giving coking units a certain advantage; as a result, there has been a clear trend toward building more coking units around the world. Due to the many advantages of delayed coking, in the current situation in China where small and medium-sized enterprises face funding constraints and there is a significant supply-demand imbalance for light oil products, especially the ratio of diesel to gasoline, delayed coking is one of the more ideal solutions to this issue.

A look at the refineries in the surrounding area, which are all building new or expanding coking units, shows the importance of coking in refineries. Coking makes a significant contribution to refineries; it’s just a bit dirty, lol. But it seems that it doesn’t receive enough attention from management, as some people believe that the technical complexity of coking is too low. :'(

We hold a similar catalytic role, but personally I feel that some managers think coking technology is simple; in fact, coking operations require precision and cannot afford any carelessness. Fortunately, it seems that the importance of coking in various plants is on the rise, and the headquarters has listed reforming, catalysis, hydrogenation, coking, and atmospheric/ vacuum distillation as the five key processes.

Well, it’s not accurate to say that one particular unit holds a more important position in the refinery; to put it simply, they are all important. In my opinion, if the supervisor of a unit has a significant role in the plant, then that unit also holds an important position, and all the people working on that unit as well have an important role within the plant.

I think if distillation is the leader in oil refineries, then delayed coking is definitely the perfect complement! It’s a pity that our coking equipment is outdated, and the high sulfur content leads to many accidents caused by equipment corrosion. As a result, those working in the coking department can’t hold their heads high in our refinery; even when taking buses, the drivers constantly scold us, saying that our clothes are too dirty and dirty the seats of the bus!

In refineries, coking is generally given priority over hydroprocessing, but now hydroprocessing has become important; coking should be ranked second or third