With high diesel inventories, how can catalytic cracking reduce the diesel-to-gasoline ratio?
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These past few days, we’ve used almost everything we have. The oil-to-agent ratio was increased, the amount of fresh agent added was raised, the reaction temperature was increased, and even the use of quench oil in the coker recycle process was adopted (the activity there should be low, but even if it’s only thermal cracking, as long as less diesel is produced that’s fine). Increase the temperature for overhead distillation, maintain medium pressure, raise the dry point of gasoline, use steam in the diesel stripping tower for stripping… Are there any other tactics that can be employed?
Try reducing the amount of slurry and reprocessed oil, and this can also help lower the amount of diesel.
We do not use slurry reprocessing; when the level in the reprocessed oil tank is high, about 10 tons of oil are reprocessed. It is not activated either if the liquid level is low.
Adjust the properties of the raw materials by reducing the slag inclusion ratio, making the raw materials slightly lighter
The problem is that the residue stock is also high. The slag inclusion ratio must not be reduced either; the processing volume can be lowered slightly. :L
This problem should be quite serious； Is it that the storage tanks in the factory are not sufficient first? No long-term considerations? The oil-to-coke ratio is an important factor in catalytic cracking processes, and the properties of the feedstock are equally important ； Changes in reaction temperature, depth, and operating conditions influence each other ； Regarding the issues raised by the original poster, first, the processing plan needs to be adjusted to change the product yield. Secondly, as part of the company’s long-term planning, it is necessary to address various related issues such as whether the processing equipment and storage tanks are sufficient, and whether the equipment is suitable for use ；
Was coking wax oil blended in? Reducing the amount of coking wax used can lower the diesel yield；
You don’t reprocess the oil – how do you control the liquid level? Do you operate at full tank capacity? Also, if the tank is not full, it means that your catalyst has high activity, so there won’t be much diesel. I think we should give more thought to the selection of catalysts; try using catalysts that are better at producing gasoline and liquefied gas, and then add a catalyst that increases the production of propylene – that would yield better results.
The mismatch between the production capacity of storage tanks and facilities is a legacy issue that is difficult to resolve in the short term. The processing volume has been adjusted at present.
After modifying our unit with MIP, the middle distillates were reduced. The processing capacity is essentially at full load, ranging from 250 to 270 t/h. The level of the reprocessed oil is adjusted through the reaction depth and the second stage of the fractionation tower, with a very small amount of oil being reprocessed. At most around 10 t/h, with no reprocessing of the slurry. The diesel yield is around 18%. RCA additives that increase gasoline production are also being added at present. The main catalyst formula was also adjusted in the first half of the year.