Automation and Control of Energy Efficient Fluid Catalytic Cracking Processes for Maximizing Value Added Products

Abstract

With an aim to optimize propylene production, petroleum oil is catalytically cracked by contacting the oil with catalyst mixture consisting of a base cracking catalyst containing an stable Y-type zeolite and small amounts of rare-earth metal oxide, and an additive containing a shape-selective zeolite, in an up-flow type fluid catalytic cracking apparatus having a regeneration zone, a separation zone, and a stripping zone. According to this fluid catalytic cracking process, the production of light-fraction olefins such as propylene is maximized by applying appropriate process control, monitoring, and optimizing systems. The present invention provides mathematical process models, including: neural networks, statistical models and finite impulse models. These various mathematical process models are used in conjunction with advanced controllers and optimizing routines to calculate optimal settings for various process parameters. A microwave based system can also be employed for optimizing the performance of a stripping zone, which further optimizes catalyst regeneration. Process model and historical data to test a predictive system can provide early warning of potential performance degradation and equipment failure in the FCC unit, which decreases overall operating costs and increases plant safety.

Description

RELATED APPLICATIONS[0001]This application is related to and claims priority and benefit of U.S. Non-Provisional patent application Ser. No. 11 / 983,078, filed Nov. 7, 2007, and U.S. Provisional Patent Application Ser. No. 60 / 857,300, filed Nov. 7, 2006, both of which are incorporated herein by reference in their entirety.TECHNICAL FIELD OF THE INVENTION[0002]The present invention relates to the process for catalytic cracking of petroleum oil. More particularly, the present invention relates to the application of advanced process control systems to catalytic cracking of petroleum oil in order to optimize the production of light olefins in relation to energy costs.BACKGROUND OF THE INVENTION[0003]In typical catalytic cracking techniques, the fluid catalytic cracking unit (FCC) cracks petroleum-derived hydrocarbons using a catalyst to achieve gasoline production. Although efforts are made to reduce side effects from the reaction, a small amount of unwanted products are produced, which ...

AI Technical Summary

Benefits of technology

[0012]The process control system (PCS) is operable to control operating conditions of the FCC unit via control parameters. These control parameters include: obtaining predetermined process models; monitoring feed data, products characterization data, and operating conditions; selecting one of the predetermined process models based on the monitored feed data, monitored products characterization data and monitored operating conditions; selecting one of the predetermined process models based on the monitored feed data, monitored products characterization data and monitored operating conditions; calculating simulated-optimized-operating conditions using the selected predetermined process model; adjusting the operating conditions to correspond with

Problems solved by technology

Although efforts are made to reduce side effects from the reaction, a small amount of unwanted products are produced, which include: liquefied petroleum gas (LPG), cracked gas oil and the like, and coke, which is deposited on the catalyst and thereby reduces the catalyst's effectiveness.

However, the methods taught by the above references failed to produce sufficient light-fraction olefins selectively.

For example, the methods taught by using a reduced catalyst contact time resulted in a decrease in the conversion of light-fraction olefins to light-fraction paraffins due to the methods' inhibition of a hydrogen transfer reaction.

Furthermore, the lack of hydrogen transfer also led to a decrease in the conversion of heavy-fraction oils to light-fraction oils.

The method teaching the use of the high temperature cracking reaction resulted in a concurrent thermal cracking of heavy-fraction oils, which thereby increased the yield of low-value, dry gases.

Lastly, the use of pentasil-type zeolites enhanced the yield of light-fraction hydrocarbons by excessively cracking

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