Refining and Petrochemical Processes Integration
Dr Marcio Wagner da Silva on the future of the downstream industry and how better integration between refining and petrochemical production processes appears as an attractive alternative.
To reduce environmental impacts and refining margins increasingly lower.
The current scenario presents great challenges to the crude oil refining industry, prices volatility of raw material, pressure from society to reduce environmental impacts and refining margins increasingly lower. The newest threat to refiners is the reduction of the consumer market, which in the last years became common news about countries that intend to reduce or ban the production of vehicles powered by fossil fuels in the middle term, mainly in the European market.
Facing these challenges, search for alternatives that ensure survival and sustainability of the refining industry became constant by refiners and technology developers. Due to these similarities, better integration between refining and petrochemical production processes appears as an attractive alternative.
The petrochemical industry has been growing at considerably higher rates when compared with the transportation fuels market in the last years. This, additionally represents a nobler destiny and less environmental aggressive, to crude oil derivatives. The technological bases of the refining and petrochemical industries are similar which lead to possibilities of synergies capable to reduce operational costs and add value to derivatives produced in the refineries.
Figure 1 presents a block diagram that shows some integration possibilities between refining processes and the petrochemical industry.
Figure 1 – Synergies Possible between Refining and Petrochemical Processes.
Process streams considered with low added value to refiners like fuel gas (C2) are attractive raw materials to the petrochemical industry, as well as streams considered residual to petrochemical industries (butanes, pyrolisis gasoline, and heavy aromatics) can be applied to refiners to produce high quality transportation fuels. This can help the refining industry meet the environmental and quality regulations to derivatives.
The integration potential and the synergy among the processes rely on the refining scheme adopted by the refinery and the consumer market, process units like Fluid Catalytic Cracking (FCC) and Catalytic Reforming can be optimised to produce petrochemical intermediates to the detriment of streams that will be incorporated into the fuels pool. In the case of FCC, installation of units dedicated to produce petrochemical intermediates, called petrochemical FCC, aims to reduce to the minimum the generation of streams to produce transportation fuels; however, the capital investment is high once the severity of the process requires the use of material with noblest metallurgical characteristics.
An example of FCC technology developed to maximise the production of petrochemical intermediates is the RxPRO™ process by UOP Company. This process combines a petrochemical FCC and separation processes optimised to produce raw materials to the petrochemical process plants, as presented in Figure 2. Other available technologies are the HS-FCC™ process commercialised by Axens Company, and INDMAX™ process licensed by McDermott Company.
Figure 2 – RxPRO™ Process Technology by UOP Company.
Figure 1 indicates the integration between process streams. However, operational costs can be considerably reduced through the integration of utilities as steam, water, hydrogen, etc. Normally, refineries have low availability of hydrogen while petrochemical plants can export this utility; on the other hand, petrochemical processes have high demand by electric and steam power that can be supplied by refineries in an integrated process.
Bottom barrel process units such as Delayed Coking can be quite versatile in this scenario; petroleum coke gasification can produce syngas, which in turn can be used as raw material to produce high-demanded chemicals, like ammonia, methanol, sulphuric acid, dimethyl ether, etc. The use of IGCC power generation plants can ensure energy supply to the refining and petrochemical processes, an example of this technology is the FLEXICOKING™ process, developed by ExxonMobil Company.
Some process technologies were developed aim to produce petrochemical intermediates from streams considered secondary to refiners, a good example is the AROMATIZATION™ process developed by GTC Company to produce aromatics from olefins (C6-C8) which are produced in FCC units. The LCO-X™ process developed by UOP Company is capable to convert Light Cycle Oil (LCO) produced in FCC units in aromatics with high added value.
Light paraffin dehydrogenation processes also allow a better integration among refineries and petrochemical plants once convert residual streams (fuel gas) into petrochemical intermediates with high added value.
One of the available dehydrogenation technologies is the CATOFIN™ process, commercialised by McDermott Company, as presented in Figure 3.
Figure 3 – Simplified Scheme for CATOFIN™ Dehydrogenation Technology by McDermott Company.
The synergy between refining and petrochemical processes raises the availability of raw material to petrochemical plants and makes the supply of energy to these processes more reliable at the same time ensures better refining margin to refiners due to the high added value of petrochemical intermediates when compared with transportation fuels. Another advantage is the risks reduction of transportation fuels oversupply, facing the current scenario of demand reduction and restriction of fossil fuels.
It’s important to consider that integrated processes lead to a higher operational complexity, however, given current and middle term scenarios to refining industry, a better integration between refining and petrochemical processes is fundamental to the economic sustainability of the downstream industry.
Fahim, M A; Al-Sahhaf, T A; Elkilani, A S – Fundamentals of Petroleum Refining. 1st edition, Elsevier Press, 2010.
Gary, J H; Handwerk, G E – Petroleum Refining – Technology and Economics. 4th edition, Marcel Dekker, 2001.
Robinson, P R; Hsu, C S – Handbook of Petroleum Technology. 1st edition, Springer, 2017.
Dr Marcio Wagner da Silva
He is a Process Engineer and Project Manager focusing on Crude Oil Refining Industry based in São José dos Campos, Brazil. Bachelor in Chemical Engineering from University of Maringa (UEM), Brazil and PhD. in Chemical Engineering from University of Campinas (UNICAMP), Brazil, he has extensive experience in research, design and construction to oil and gas industry including developing and coordinating projects to operational improvements and debottlenecking to bottom barrel units. Moreover Dr Marcio Wagner has MBA in Project Management from Federal University of Rio de Janeiro (UFRJ) and is certified in Business from Getulio Vargas Foundation (FGV).