
From slide rules to nanotechnology – how cutting-edge technology has transformed refining in 35 years
Sal Torrisi, Hydrocracking Market Manager, describes the technological advancements that culminated in global ULSD projects.

By Sal Torrisi on Dec 13, 2020
Early in my career as a chemical engineer, I had the opportunity to work in a role that focused on deploying technologies at refineries globally. I went through an intense period of knowledge growth, working for and being mentored by six to seven engineers who had 25 to 35 years of experience. I did everything I could to soak up their experiences and learnings, not knowing how valuable it would be in my career development.
In those days, computers were not heavily used by engineers, and PCs did not commonly appear on desktops until the early ‘90s. We used mainframes to run simulation programs, and the experienced engineers came from the days when they used slide rules in school.
I was the computer guy, having started programming using Basic on a PC back in high school. There was a good relationship between my mentors and me as we both had skills the other needed; I would help them get things done because I could use new-generation computing tools, and they had the smarts and the knowledge that they shared with me, which we combined to solve problems together in new, more efficient ways.
As I prepare to retire and look back on my 35-year career in refining, the most notable changes I’ve observed in the industry are the tools we’ve used to transform our work and to migrate into a much more efficient business producing more and cleaner products for our customers – from the days we used simple strip-charts to record/monitor the reactor temperature – to the scientific advancements we’ve made within the last five years leveraging nanotechnology.
Managing molecules with a future perspective
When we started looking at molecules decades ago, the feeds were characterised in very coarse terms. Crude was defined by five or six key properties that dictated how we turned the knobs at a plant to manage those molecules into the right products.
Now we can look at feed components down to the molecular scale. We can describe crude by more than 10,000 different molecules and, in knowing that level of detail, we can better plan how to transform them, modeling these reactions in a more detailed way. Using this information, we can then design our catalysts to tailor the molecular transformation.
For example, in our MACH portfolio, the Molecular Access Catalyst for Hydrocracking, we are able to design the zeolite pore structures on a precise, nanometer scale. It’s been fun to visualise these changes using virtual reality technology to take a ride with these molecules as they travel through the catalyst pores and are transformed from large, dirty structures to smaller, cleaner and desirable fuels, lubes or petrochemical products.
Refiners have had to adapt their operations to waves of change, as new cleaner fuels or crude flexibility requirements are being adopted around the world. What has stayed constant from my perspective, is that we’re still transforming molecules. We’re repurposing those molecules now as we look to the future and turn them into more chemicals as opposed to fuels, or turn them into lubricants or petrochemical feeds and facilitate the energy transition. In the end, it’s all about managing molecules.
Download the to explore our energy transition philosophy
Developing and deploying ultra-low-sulphur diesel (ULSD) technology around the world
As we implement new technologies to meet future requirements, I have reflected on my work facilitating connections between Shell’s global teams to apply learnings from one region to another.
Europe and the Americas were the first to move to ULSD in the early 2000s, and our team was very successful in helping refiners produce this fuel with new designs involving catalyst plus reactor internals. I was involved with new product and process development in a variety of roles and contributed to 40 ULSD designs just in the Americas.
We submitted those designs to the Platts Global Energy Award and won the award for Commercial Technology of the Year in 2007. The award was reflective of the good collaboration between catalyst and process technology groups we’ve had at Shell Catalysts & Technologies over the years, and accepting it on behalf of the company was a highlight of my career.
As various regions around the world also began adopting ULSD regulations, we were able to apply our learnings more readily and confidently based on our first experiences, improving our technology offering each step of the way. It’s been a joy to help connect our colleagues in the U.S. and Europe with our colleagues in developing markets to carry on this technology transfer within our hydroprocessing community.
Continuous transformation in the refining business
The refining business has gone through a number of transformations throughout my career. The next transformation is near, and it feels as big as any before. I’ve participated in refining industry technology groups and conferences, as one of Shell Catalysts & Technologies’ representatives that networks with other refining colleagues to anticipate and adapt to changes.
I’m excited for the refining industry overall because I know they will rise to meet the challenges ahead. Refiners are very shrewd in identifying future needs and figuring out how to adapt existing equipment to provide cost-effective solutions.
I have seen the industry adapt numerous times – from finding new ways to produce octane so that lead could be removed from gasoline, to the continuous efforts to improve air quality via clean fuels production to the reduction of emissions at the plants themselves. These things are not technologically or financially easy, but the industry has been able to adapt quickly while still providing better, yet affordable products to our customers.
Learn more about preparing for the disruptions that lie ahead
With the energy transition generating interest in increased petrochemical integration, incorporation of more renewable molecules into fuels, improved energy efficiency and efforts that support decarbonisation of the energy supply, I know refiners will figure out how to either build new equipment or adapt existing equipment to meet some of those new challenges.
They’ll also be able to leverage digital technology to make the processes much more efficient. New materials are being introduced too, much like we’re doing in the creation of new catalysts, that will open up opportunities to design or retrofit units that can substantially improve performance. Ultimately refiners are going to figure how to transform feed molecules into exactly the right products with less waste and more efficiency, seamlessly integrating with petrochemical operations.
The future is going to be different, and it’s going to require a fair amount of work, but I know that the refining and petrochemical businesses are up to the challenge. In my area of hydrocracking, our global technical and commercial communities are a well-connected, highly-functioning community with regional centres of expertise, and those nodes are working together to leverage cutting-edge technology to help customers quickly adapt to changing requirements.
Learn more about optimising refinery operations with collaboration and digitisation