FCC refinery

Centennial Celebration of Catalytic Cracking

An interview with Paul O’Connor | Part 1 | A short history

The Following is an interview with Paul O’Connor, who proposes to celebrate the Centennial (100th birthday) of the Catalytic Cracking process this year.

Our first question for Paul is: why are you so interested in Catalytic Cracking and how come you chose the year 2022 for the 100th birthday of Catalytic Cracking? 

As you know, I have spent most of my professional career at Shell and at Akzo Nobel (later Albemarle) in Catalytic Cracking (1977-2004). Even after I left the oil business and started BIOeCON (2005), in the biomass conversion field I continued working on what we first called Catalytic Pyrolysis which later became Biomass Catalytic Cracking.

In fact, it started already with my first internship during my Chemical Engineering studies in 1975. That was at Shell Curacao looking for improvements of the operation of their Catalytic Cracking unit which was the heart of the refinery.

Catalytic Cracking still has a special place in my heart and when I moved out of the field to become a business development manager at Albemarle I initially resisted. 

And how come 2022? What specifically happened in 1922?

In my Akzo Nobel years I held many lectures, and when I was digging into history I found out that a guy called McAfee was already cracking hydrocarbons with a molten salt liquid Aluminum Chloride in the early 1920’s. His first patent on the subject was granted in 1922 (1), so I used that date to demonstrate the beginning of catalytic cracking. This is a great year, because it’s also happens to be my father’s year of birth.

Most people are not aware of McAfee’s discovery, and therefore I would always make the joke that this was not the McAfee from the virus scanner, but an earlier creative McAfee. 

Fig 1. McAfee 1922 patent

In retrospect I also have to note that 1922 is not exactly the correct year, as McAfee filed his patent in 1913 and already published about the subject in 1915 (2). So I must cheat a little about the age a to make the year 2022 a Centennial year. But as you know many people cheat about their age (☺). 

It took a long time to get the patent granted because of a patent dispute between Texas Company (McAfee’s initial employer) and Gulf Oil (McAfee’s later employer). McAfee claimed he was the inventor while his boss at Texas Oil company filed the patent under his own name. McAfee left Texas Company and filed the patent with his new employer Gulf Oil who won the court case in 1926.

So, the right birthday of Catalytic Cracking would be 1913?

Yes, or maybe even a year or so earlier (1912) considering the time it takes to file a patent etc. after having made an invention. That would mean 2022 is the 110th year celebration of Catalytic Cracking. 

But even then, there was some controversy (3). People found it strange that the patent was granted despite of several prior art patents and publications, most importantly the patent received in 1877 by C.D. Abel on behalf of Friedel and Crafts (4), which describes converting oil to light oil and gas with Aluminum Chloride at temperatures in the 100-600 degrees Celsius range (4). If we would assume 1877 as the birth date of catalytic cracking, then we are already at its 145th birthday. McAfee was aware of Friedel-Crafts: In 1907 while taking a course in organic chemistry, he wrote next to the discussion of the Friedel-Crafts reaction in his textbook the words “Exceedingly useful” (3).  

In any case McAfee and his company Gulf were the pioneers in commercial Catalytic Cracking. The first commercial anhydrous Aluminum chloride cracking units were constructed in 1915 and in the 1920’s Gulf had built over twenty units. Compared to thermal cracking the McAfee catalytic process had several advantages: lower temperatures and pressures and better anti-knock properties (Octane) of the gasoline. However, by the end of the 1920’s the improvements in thermal cracking balanced against the high construction costs of the catalysts, which made the McAfee process no longer economically competitive. In 1929 Gulf terminated the McAfee cracking operations. 

It took a few years before Catalytic Cracking returned but then in a different form using solid catalysts instead of liquid catalysts. Several forms of these processes emerged:

  • The Houdry process (1936): with multiple fixed-bed reactors of catalysts.
  • TCC: Thermafor Catalytic Cracking (1942): with a moving bed of catalysts
  • FCC:  Fluid Catalytic Cracking (1942) with fluidized bed catalysts

The catalysts used are mainly based on clays, natural or synthetic silica-aluminas, and of course the now famous crystalline silica-aluminas or what we now call zeolites which were introduced in the 1960’s.

When you read history about Catalytic Cracking it often starts with the Houdry Process, as in the following quote from the American Chemical Society (5).

“The first full-scale commercial catalytic cracker for the selective conversion of crude petroleum to gasoline went on stream at the Marcus Hook Refinery of Sun Company in 1937. Pioneered by Eugene Jules Houdry (1892-1962), the catalytic cracking of petroleum revolutionized the industry. The Houdry process conserved natural oil by doubling the amount of gasoline produced by other processes. It also greatly improved the gasoline octane rating, making possible today’s efficient, high-compression automobile engines. During World War II, the high-octane fuel shipped from Houdry plants played a critical role in the Allied victory.”

So, another possible birthday is 1937, which would mean that the “grand old lady” as they often call her in refinery technology is now 85.

The following is quoted from reference (5):

In the early 1920s, the French engineer Eugene Jules Houdry began his search for a catalyst to produce gasoline from lignite. A catalyst is a substance that can increase the rate at which a chemical reaction occurs, without itself being changed. Because it has the potential to produce very selective results, such as the cracking of high-boiling petroleum fractions to gasoline, a catalyst can give a particular process a competitive advantage. As an avid participant in the sport of automobile racing, Eugene Houdry was acutely aware of the importance of high-performance fuels for successful machine performance. As a Frenchman, Houdry was also aware of the growing need for gasoline in a country that was deficient in its own petroleum resources.

In 1922, Houdry learned about an exceptional gasoline derived from lignite that was being produced in a catalytic procedure by E. A. Prudhomme, a pharmacist in Nice, France. Houdry visited Prudhomme and persuaded him to move to Beauchamp, near Paris, where Houdry and some of his business associates financed and set up a laboratory. For the next few years, Houdry worked closely with Prudhomme and others to develop a workable lignite-to-gasoline process. Supported by the French government, Houdry’s syndicate built a demonstration plant that processed 60 tons of lignite per day to produce oil and gasoline. The plant started operations in June 1929, but the results were disappointing, and the process was not economically competitive. The government subsidy was withdrawn, and the plant was shut down in that same year.

In the lignite-to-gasoline process, the solid lignite was initially broken down by heat to produce viscous hydrocarbon oil and tars, then the oil was further converted by an added catalyst to produce lower-boiling hydrocarbons similar to the gasoline fraction derived from petroleum. Although much emphasis had been placed by others on nickel-containing catalysts, Houdry discovered that a clay mineral named Fuller’s Earth, a naturally occurring aluminosilicate, could convert the oil derived from lignite to a gasoline-like product. Working with this knowledge, Houdry focused his attention on the application of catalysis to petroleum processing.

Can you tell us when and how your involvement started in Catalytic Cracking?

As I mentioned earlier, in 1975 I did an internship at the Shell Refinery in Curacao and my task was to support the Fluid Catalytic Cracking (FCC) technologist at the time with a few of his smaller projects. The FCC process is really fascinating as a powdered catalyst is fluidized by vapor (hydrocarbon, steam, or air) making it behave like a fluid which then circulates between a reaction section where oil is cracked to lighter products and some carbon (we call coke) is formed on the catalyst and the regenerator section where the coke is burnt off to re-generates the catalyst. The heat generated is used to vaporize the oil. It’s a quite complicated system and set of conditions to operate the FCC properly in what they call a “Heat-balanced” mode.

Fig 2. Typical FCC Reactor & Regenerator set-up

Anyway, I enjoyed my internship and back at the university I focused my studies more on chemical engineering and on the fluidization and flow of powders. My Professor K. Rietema (6) was a world expert in these fields, and I learned a lot from him. After my graduation I joined the Shell Manufacturing & Development  (MFD) department in The Hague. I started in the Distillation group, moved on to Thermal Cracking and then into Catalytic Cracking. Thermal and Catalytic cracking were organized into one section, and I got the opportunity to work with some very talented and knowledgeable people in an extremely friendly and creative atmosphere. My first patent on the FCC process is from this period (7).

I would also like to discuss Thermal Cracking: Thermal Cracking was already discovered in 1861 (8). As often happens, this discovery was made by accident because a lab assistant left a crude oil distillation unit running alone and later noticed that that part of the heavy oil had been converted into gas and lighter oil components. There is always some competition between these two processes and in very simple terms: Catalytic Cracking can only win if the benefits of the catalyst outweigh the extra costs and complexity of the process.

The chronology of development can be roughly summarized as follow:

1861 Invention of (thermal) Oil Cracking 
1877 Friedel-Crafts invention of AlCl3 catalysts and catalytic oil cracking
1913 McAfee invention of AlCl3 based catalytic cracking process
1922 McAfee process patent granted
Houdry & Prudhomme develop lignite cracking process
1929 McAfee Units & Houdry-Prudhomme demo plant shut down
1937 Houdry develops commercial cracking process based on acidic clays

What were and maybe still are the main challenges in FCC development?

There were/are a lot of new developments in FCC both on the process side as well as on the catalyst side, while the feedstocks to the FCC unit were/are also changing and often becoming heavier with more contaminant metals etc. As an example, the combination of more active catalysts, shorter contact times and heavier feeds meant that mass transfer was becoming the limiting factor in the FCC unit. 

This interview will be continued in Part 2: “Past and future challenges in FCC”
A special dedication to Mr. Catalyst: Herman Lovink 

We would like to dedicate this article in memory of Mr. Herman Lovink who passed away this year. Herman was a great mentor and a good friend for many of us who worked at Ketjen Catalysts and/or Akzo Nobel Catalysts. We called him Mr. Catalyst and he had excellent relationships all over the world always stimulating cooperation and development with his ever-present smile and laugh. He was our global ambassador. Although Herman was knowledgeable in many fields his true love and passion was for Fluid Catalytic Cracking. 

Herman leading a Q&A panel on fluid Catalytic Cracking (1980’s) at the Ketjen Catalyst Symposium

(1) US 1,424,574 – A.M. McAfee (1922)

(2) J of Ind Eng. Chemistry Vol 7, nr 9 p 737- 741– A.M. McAfee (1915)

(3) A.M. McAfee Commercial Cracking Pioneer, Bul. Hist. Chem 21 p12 – P. Buonora (1989)

(4) C.D. Abel for Friedel and Crafts, British Patent 4769 (1877).

(5) www.acs.org/content/acs/en/education/whatischemistry/landmarks/houdry.html

(6) Powders what are they? – K. Rietema – Powder Technology, 37 (1984) 5 – 23

(7) Process for the fluid catalytic cracking of a hydrocarbon feedstock – CA1183793A (1981)

(8) Pyrogenesis of Hydrocarbons – E. L. Lomax – J of Ind Eng. Chemistry Vol 9, p897 (1917)

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