Distillation Distilled: Is Industry Adapting Fast Enough?

David Martyn looks back at TCE’s recent series of distillation articles and asks whether chemical engineers can be more proactive when it comes to making a meaningful contribution to society

The 2024 Statistical Review of World Energy² shows that, for the first time, the global emissions of CO2 associated with energy exceeded 40 Gt, a 70% increase since 1990. However, in some parts of the world there is evidence of real progress. For example, UK CO2 emissions have reduced by 46% since 1990.²

Distillation is an energy intensive method of separation and accounts for 40% of energy use in the petrochemical industry. Despite this, we continue to use distillation for almost all separations in these industries. Recent articles in TCE highlight many opportunities to save energy, while improving operational safety and efficiency:

• The article on dividing wall columns (see TCE 984) showed us that this technology could reduce energy consumption by up to 30%, as well as reducing capital costs. Dividing wall columns were first patented in the 1930s but in the 20th century only a relatively small number of columns were built. In the last decade, dividing wall columns have become much more common with hundreds of units now in operation and designs continuing to develop to increase the applications that can use the concept. A real step forward but one that took almost 100 years to go from an idea to widespread adoption
• The article on more efficient column internals (see TCE 985/986) showed the impact of lower pressure drop and better separation efficiency. One of the key developments in this area was the invention of structured packing which was first patented in 1953. During the 1980s, its low pressure drop and good separation efficiency led to widespread adoption in the air separation industry. By the mid-1990s, other industries were seeing the value and by the early 2000s many had adopted this “new technology”. Structured packing has been more widely implemented than dividing wall columns and took only 50 years from idea to adoption
• Heat pumps are also well understood (see TCE 987) and are increasingly common in a few (narrow boiling point distillation) applications. The first application of vapour recompression in distillation was as recent as 1985⁴ with a few operators now beginning to look at larger-scale implementations to find innovative ways to take advantage of the technology and its potential large energy savings

Beyond the focus of the distillation series there are well-known alternatives to distillation which can be much more energy efficient in appropriate settings. Universities and companies globally continue to do expansive research into membranes which, in some industries (such as water and gas), have found widespread commercial application. Membranes were industrialised in the 1960s for reverse osmosis water purification.

However, there are still massive opportunities to find ways to use them in other applications where fouling or the difficulty of achieving the required separation is currently a barrier.

In the last 100 years we have made some very significant progress in energy knowledge and how to reduce emissions but these techniques have not yet been implemented on a global scale.

We can always do better at teaching each other and sharing across industrial sectors so that great implementations in one industry can be transferred for wider adoption and create greater impact on our environment

In many cases the solutions exist but there are barriers to widespread implementation. Let’s consider the most common barriers to adoption:

1. the economic environment does not support the change conservatism in the face of new risks
2. the organisation considering change does not have the knowledge to give assurance of a successful implementation
3. commercial confidentiality

All of these will be true in some cases, but what can we do to help alleviate the concerns?

The economic environment is perhaps outside an engineer’s direct sphere of influence but as a wider community we can have an impact. We can do everything in our power to manufacture safe and reliable processes at the minimum capital and operating cost. When addressing sustainability challenges, rather than perpetuating the expectation that all problems can be solved at no cost, we need to be prepared to talk to the wider society to educate and encourage them to get invested in the issues.

I would group the second and third points together. They can be summarised by the phrase “we don’t do it like that here”, which seems to be a common sentiment across the globe! We can always do better at teaching each other and sharing across industrial sectors so that great implementations in one industry can be transferred for wider adoption and create greater impact on our environment. Structured packing in the air separations industry was a great example of this.

To be successful we need to ensure engineers are up to date with the latest innovations and have pathways to stay informed. How would you feel going to a doctor who based their treatments only on what they had learnt at medical school, which might have been many years before?

Commercial confidentiality in this context sounds like a problem, but we must assume that if someone owns the intellectual property to a piece of technology that would help reduce energy use, the owner would be keen to maximise its value by getting it widely used.

Given that we recognise barriers to widespread adoption exist. How can we as an engineering community increase the pace of implementation?

Change clearly takes time. The current best case, presented here, of structured packing was 50 years from ideation to widespread adoption. Very few people work for 50 years, so we need to build bridges across multiple generations and geographies to combine the best of academia and industry. We must regard sharing of ideas as paramount and engage with teaching the next generation of engineers to build on the foundations already developed, as well as learning from the failings of their predecessors so they don’t repeat the same mistakes.

Globally, innovation occurs on a wide playing field – from the academic researchers at universities to the engineers progressing commercialisation. In both fields, there are newly qualified, innovative workers with IT skills that make previous generations look pedestrian. Wouldn’t it be good to create fantastic knowledge-sharing communities where professionals working on similar technologies could get together regularly to share and learn? This would create more value for their own organisations by expanding knowledge and allowing them to challenge the norms of their own company. They might even help educate the wider population to create demand for change.

This is the concept of IChemE’s special interest groups. They are great places to get involved and gain knowledge by collaborating with others working in your own field of interest:

• If you don’t know if there is a group for you, have a look on the IChemE website³
• If you already know which group(s) you align with but haven’t got involved, challenge yourself to do so
• If you are already involved, challenge yourself to contribute more, become a change agent that makes things happen, both at your place of work and beyond. Join the committee, offer to present a webinar or host an event
• Above all else be proactive in driving change so you don’t have to wonder why nothing happened on your watch. This might be by making things happen yourself or by influencing policy to make the right technical solutions become economically viable

The knowledge exists to drive change faster than we have to date. We shouldn’t wait for a magic solution, we need to apply the knowledge we have today. As engineers we need to be prepared to influence policymakers to create an economic environment which enables investment in energy efficiency and lower carbon technologies.

So, what am I doing differently? In my day job, making sure our corporate knowledge is organised and accessible so that we can use it to train the rest of the organisation and ensure we increase value by using knowledge. In chairing the IChemE Fluid Separations Special Interest Group where we continue to run a diverse range of meetings and webinars, aiming to broaden our reach in both demographic and geographic terms. It would be great to run events that lead to ideas tested in one industry being adopted by other industries. We would, of course, welcome contributions!⁴

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This article follows a series written by experts helping chemical engineers identify opportunities to improve distillation operations. To read the series, visit: https://www.thechemicalengineer.com/tags/distillation-improvement-opportunities

References

1. Statistical Review of World Energy, Energy Institute, 2024
2. Department for Energy Security and Net Zero, 2022 UK Greenhouse Gas Emissions, Final Figures, 2024
3. M Zogg, History of Heat Pumps, Swiss Contributions and International Milestones, Swiss Federal Office of Energy, 2008
4. https://www.icheme.org/knowledge-networks/communities/special-interest-groups/