Geismar Chemical Plant, Louisiana, USA 2015 (1)

Behind Shell technologies: Busting ethylene oxide catalyst paradigms with John Lockemeyer

Leading scientist John Lockemeyer discusses his work behind major improvements in EO catalyst technology.

By John Lockemeyer on Oct 19, 2020

Shell is an industry leader in ethylene oxide (EO) catalyst. One of the most prominent individuals in EO production is John Lockemeyer, Principal Researcher, Shell Catalysts & Technologies (SC&T):

  • John has invented three of SC&T’s five catalyst families and has had a major impact on the other two.
  • He has been granted almost 40 U.S. patents, most in EO catalysts, and received the 2018 Southwest Catalysis Society Award for Excellence in Applied Catalysts.

In this interview, John discusses how he had contributed towards making major improvements in EO catalyst technology by developing a fundamental understanding of catalysis and applying knowledge of commercial challenges to the research process.

Q: John, you and your colleagues call yourselves the Paradigm Busters! Would you elaborate on that?

When we were developing Shell Catalysts & Technologies’ high-performance (HP) EO catalyst family, there were six generally held beliefs about commercial EO catalysts that turned out to be either outdated or incorrect when we examined them closely. Working through each of these myths led to a catalyst with far greater selectivity and activity stability than any previous EO catalyst.

Finding opportunities to invent

We made phenomenal progress by challenging common beliefs. You often find that paradigms exist as folklore well beyond the technology to which they were originally applied.

I tend to ask the scientists and engineers questions such as, “Why can we not do such and such?” If the answer is, “That is just the way it is; it is the way it has always been,” then I see that as an area ripe for exploration. If you challenge a paradigm, you typically find that it has outlasted its reason for existing, and that means there is an opportunity to invent.

Explore how Shell Catalysts & Technologies is driving the future of process technologies

Q: So, it is about being sceptical of the status quo?

Absolutely. The HP and hybrid (HY) catalysts are good examples. Until the mid-1980s, Shell only had its high-activity (HA) catalyst, which made EO with about 80% selectivity. Then, with the discovery of the rhenium promotion effect by Ann Lauritzen (a former researcher in Shell’s EO catalyst group), the high-selectivity (HS) catalyst family was born. These catalysts would operate at about 87% selectivity, but with shorter lifetimes, although these improved with subsequent generations.

Major discoveries begin by asking a fundamental question

Shortly after I joined the EO catalyst R&D group in 1994, my colleague Randy Yeates and I asked a fundamental question: Why can we not invent a catalyst that has both high activity and high selectivity?

Like the rest of the industry, we seemed to have accepted that these were mutually exclusive factors. What we found was that there was no reason, according to the fundamental science, why it could not be done; we just did not have the technology. So, we embarked on a programme aimed at creating a catalyst that would be both highly selective and very active.

In 2004, we did just that: we commercialised the HP family, which combines the attributes of HA and HS catalysts. In 2000, on the way to the HP invention we developed the HY family, with selectivity between that of the HA and the HS catalysts (about 84% under the same conditions) and that was also very active. It starts out like an HA catalyst, but then becomes more selective.

Q: How did you work with other team members across the organisation?

Teamwork in abundance

The inventions that we have commercialised over the years build on the achievements of the scientists who preceded us, as well as the dedication of the R&D, manufacturing and business teams within Shell Catalysts & Technologies.

Research requires teamwork in abundance. When I first came into the group, I immediately realised that the problems were too difficult to solve on my own. I just did not have the skill set, so I recruited people by trying to get them excited about my problem: surface scientists, physicists, engineers and other chemists. It is imperative, if you are going to solve problems that have been there for many years, that your team provides different skills and perspectives.

The Shell connection

The EO R&D group serves a major business with a strong track record of innovation and growth, so we have always been prepared to invest in research. But it requires patience and commitment from the business, especially in EO, because it can take many years to commercialise a new idea. Fortunately, Shell has remained committed to our R&D efforts over many decades.

It is key that we are part of a major catalysis organisation and can draw on expertise from different technology areas. Shell Catalysts & Technologies is a market leader in refining and petrochemical catalysts that operates research laboratories, development facilities, manufacturing plants and business units throughout the world.

We can also draw on Shell’s expertise at-large. Shell operates large, complex industrial refining and petrochemical facilities worldwide. We really need to have that depth and breadth to make advances in mature technology areas.

Collaboration is also important. We have long-term research partnerships with leading companies outside Shell. For instance, our work with catalyst carrier specialist Saint-Gobain NorPro has led to some substantial advances.

Related reading: Optimising refinery operations with collaboration and digitisation

Q: Catalysts are only part of the story; the process technology is also vital. How closely do you work with your process technologist counterparts?

Stronger catalyst led to process design improvements

We have implemented some really valuable performance improvements through the integration of catalyst and process technology. When we were commercialising the HP catalyst it became clear that, quite frankly, it was so good, so stable, the existing process was not going to challenge it.

So, our process technologists worked with the catalyst R&D team and redesigned the process around the much more stable and selective HP catalyst, thereby increasing the design work rate (the volumetric production rate) significantly. That is extremely valuable for customers; for example, it means that a reactor can be eliminated from the line-up, which would substantially reduce the capital cost.

Q: Could you share some context about your research?

One of the most notable work streams focused on understanding the sintering of silver particles on the surface of the catalyst. This issue affects all silver oxidation catalysts. The reaction occurs at relatively high temperatures and causes the catalyst to lose activity. The higher the temperature, the faster the sintering process proceeds, so it feeds on itself.

Extending the catalyst life

When we started the HP catalyst development, we investigated how to control the sintering because, if we could solve that problem, we could extend the catalyst life. The result was a detailed understanding of the sintering process and methods for controlling it that helped us to improve the catalyst’s stability. It involved very high-tech techniques such as electron beam lithography, which is used in the microchip industry.

Q: In addition to electron beam lithography, what other techniques have you used?

We have also used electron microscopy, X-ray photoelectron spectroscopy, computational chemistry and a wide variety of other techniques. We have also done isotope labeling studies and other kinetic studies to help understand the fundamentals of the catalyst and the catalytic process better.

Today’s catalyst development requires state-of-the-art techniques

Many of these technologies are cutting edge. And they have to be because inventing new and better EO catalysts, or any kind of catalysts for that matter, requires state-of-the-art science. In the past, you might have been able to develop a better system through an empirical approach involving trial and error, but you can only take that so far.

Creating value for EO/EG plant owners and operators through catalyst & process optimisation

Q: Shell is a major EO producer; how does that inform your R&D focus?

Applying customers’ challenges to the research process

It is the interactions between teams and customers that really matter. Interaction with all customers, whether Shell or third-party businesses, is critical. I know many customers on a first-name basis.

"If you do not understand what the challenges are in the commercial environment, there is the risk that you will invent something that cannot be useful."

Ideally, when an invention goes from the laboratory to commercial fruition, customers will want to buy it because it will solve some problem they have encountered. That was the case with the HY catalyst, which enabled the high activity market to run at higher selectivity, and it was so for the HP catalyst, which enables most plants to run with high selectivity at higher production rates for longer.

It is proving to be the case with the new high-tolerance (HT) catalyst that we launched recently, too. The addition of HT to Shell Catalysts & Technologies’ product portfolio enables us to operate in any of the conditions that we encounter in plants around the world.

So, having intimate knowledge of our customers’ challenges, and having them in the backs of our minds when thinking about what to invent, is important because otherwise we would be researching in a vacuum and that is unlikely to be useful.

Q: What do you find most inspiring about catalysis and chemistry? What drives you?

Like other chemists, I get to think of something that has never existed and then make it real. With EO catalysts, these inventions are deployed on a world scale and affect the global economy and lives of people worldwide, and that is a huge kick.

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