Call for production plan proposals for catalytic cracking units

First, select the appropriate type of catalyst. Second, change the reaction temperature and reaction depth. Third, change the side-line extraction. Fourth, changes in pressure and pressure difference of the two devices. Fifth, changes in the amount and injection location of the terminator

Let me explain the general approach to operation: 1. Reaction stage: Control the appropriate degree of reaction by referring to different schemes; if a liquid hydrocarbon or diesel-based scheme is used, gasoline reprocessing (injected through the lower nozzle) can be employed. 2. Fractionation and stabilization stage: Maximize the yield of the desired product. 3. Use catalysts with good selectivity, such as those that favor the production of diesel or liquefied gas. 4. Additives may be used when necessary. In any case, these approaches will disrupt the original equilibrium of the plant, so we need to adjust the operations to find a new equilibrium point

The diesel-intensive production scheme involves catalytic cracking reactions, which are parallel sequential reactions, with diesel serving as an intermediate product. Its yield is greatly affected by the degree of reaction; therefore, measures to increase diesel production start with reducing the degree of reaction. A. Reaction unit adjustment measures: 1. Reduce the temperature at the exit of the lift pipe to minimize secondary cracking and increase the yield of intermediate fractions. (The one-way conversion rate will decrease.) 2. Increase the flow rate of the terminator and use a nozzle for applying the terminator. Reduce the riser reaction time to minimize further cracking of the intermediate fractions. 3. Increasing the reprocessing ratio is also aimed at reducing the reaction depth. Defect: ① Limits the processing capacity of the device, reducing the amount of slag added to it. ②Increasing the regenerator charring load, and untimely adjustments lead to carbon buildup. If only the main air volume is adjusted, it will lead to increased power consumption. It is best to increase the regenerator pressure to improve the coking effect. 4. Control the catalyst activity; a lower catalyst activity can reduce the degree of reaction. As a result, it is necessary to increase the oil-to-reagent ratio to improve reaction selectivity and reduce coke formation, thereby increasing the yield of diesel. The above adjustments have a negative impact by reducing the one-way conversion rate, which leads to an increase in the reprocessing ratio and thus higher energy consumption of the plant. B. Fractionation unit adjustment measures: (Expand the diesel processing stream while ensuring that the diesel’s flash point meets the required standards.) ) 1. Reduce the top temperature of the fractionation tower to lower the dry point of gasoline. The purpose is to transfer the “tail” components of gasoline into diesel, separate out the heavy gasoline, and simultaneously increase the octane rating of gasoline. During the adjustment process, appropriately increase the cold reflux flow rate of the fractionation tower. The advantages include increasing the partial pressure of the gasoline components in the fractionation tower (paying attention to the pressure in the settler to prevent pressure buildup in the reactor and adjusting the inlet pressure of the air compressor); it also helps prevent the top product temperature from dropping too low, which could cause the top product pump to experience vacuum conditions. It also prevents salt buildup at the top of the fractionation tower. (Note: Ensure that the extraction temperature at the top of the fractionation tower is not lower than 130°C; reduce the amount of material extracted from the top accordingly.) 2. Increase the diesel extraction temperature and the extraction temperature at the intermediate stage. The purpose is to reduce the diesel component in the reprocessed oil, to appropriately lower the intermediate stream flow rate, and to allow the intermediate stream to take a longer cold path in order to ensure the temperature at which diesel is extracted. 3. Optimize the diesel stripping steam while ensuring compliance with the minimum diesel flash point requirements. Minimize the initial distillation temperature of diesel.

You’ve run out of ideas; I can only offer my support now!

I think the most crucial aspect is the development of catalysts – developing different catalysts tailored to the desired target products (which essentially involves research on catalyst additives), including factors such as catalyst selectivity, hydrothermal stability, and so on. Current catalytic cracking technology is already fairly mature, so different catalysts can be selected based on the desired product, and different process operating conditions can be chosen in accordance with those catalysts.

This post was last edited by China Petroleum Person on 2012-2-29 at 20:37. We are currently building a catalytic cracking unit with a capacity of 400,000 tons per year for oil processing; the process package comes from KBR. There are no such units in China, and the only one of this kind exists in South Korea. After reviewing the process package documents, I found that the most important part is the reaction and regeneration system, which uses coaxial reactors. This differs somewhat from China’s existing catalytic cracking technology, but the difference isn’t significant. Those foreigners really know how to do things – they try to turn the reactors into patented equipment. Things that can be manufactured in China are forced to be turned into patented products as well.

Schemes to increase gasoline production: 1. Reduce or stop using reprocessed gasoline as a terminator; 2. Raise the dry point of gasoline to the upper limit; 3. Use catalysts with good selectivity; 4. Reprocess lightly contaminated oil; 5. Increase the stripping steam to boost liquid yield; 6. Lower the reaction temperature to prevent secondary cracking, etc

Diesel raises the flash point, reduces the reprocessing ratio; the termination dose needs to be adjusted properly, along with the use of appropriate catalysts and a suitable reaction temperature. The upper limit for the dry point of gasoline should be maintained, and exothermic reactions should be minimized as much as possible for the gasoline production process