'Chemical cybernetics' and the problem of climate change

(Part 2 of 3)

In 1971, Charles Hohmann completed a Ph.D. thesis entitled “Optimal networks for heat exchange” at the University of Southern California. This thesis was an early example of how systematic computational techniques can be used to aid in the proper design of efficient industrial processes. Unfortunately, his work proved to be a little bit ahead of its time, since the first global oil crisis of 1973 was still two years away and energy conservation had yet to become an important consideration in industry. In the wake of the oil shocks of the 1970s, it was the subsequent work of Bodo Linnhoff and co-workers at the University of Manchester Institute of Science and Technology (UMIST) that popularized what came to be known as “pinch analysis,” a family of methods to design heat recovery streams in industrial plants. In the late 1970s and early1980s pinch analysis grew into a sub-discipline in the field of process systems engineering (PSE). PSE in turn is the computational branch of chemical engineering, covering such applications as process synthesis, design, control and operation. As I noted last month in the previous installment of this column, in Russia, PSE is also referred to by the far more exotic and awe-inspiring name of “chemical cybernetics.”

The evolution of pinch analysis in the 1970s illustrates how the contemporary issues influence the growth of ideas. Through the work of bright researchers in Europe, North America and Asia, pinch analysis was further extended to numerous applications over the past few decades. One recent development is “carbon emissions pinch analysis” or (CEPA), which I first proposed with my long-time collaborator from the University of Nottingham’s campus in Malaysia, Dominic Foo, in an article entitled “Pinch Analysis Approach To Carbon-Constrained Energy Sector Planning” that appeared in the journal Energy in 2007. Our work demonstrated how energy resources can be allocated optimally to energy demands given CO₂ emission constraints. This work has proven to be highly successful, and has been cited dozens of times since it first appeared half a decade ago. One of the first to take interest in CEPA was our late colleague Toshko Zhelev, former professor of Chemical Engineering at the University of Limerick in Ireland. Among other things, it was Toshko who first coined the term “CEPA” when Dominic and I were still using the term “carbon pinch.” CEPA methodology played a key role in the Ph.D. work of one of Toshko’s students, who used it to analyze Ireland’s energy sector. There have also been researchers in India, China, Hungary and New Zealand who have developed extensions and applications of CEPA. I find the interest by Indian and Chinese researchers particularly gratifying, considering that those two countries are major sources of CO₂ emissions due to their sheer size. CEPA has also led to a series of other papers from my research group at La Salle, developed jointly with Dominic’s team in Malaysia and a third colleague, Santanu Bandyopadhyay, of the Indian Institute of Technology-Bombay. Some of the new applications we have worked on include the planning of low-carbon energy systems such as bioenergy supply chains and power generation with carbon capture and sequestration (CCS). In addition to CO₂ emissions, we have shown how the optimal allocation principles can be readily extended to other measures of energy “quality” such as land footprint, water footprint and inoperability risk. Finally, this relatively new branch of pinch analysis has led to the training of several Ph.D. and master’s students in the Philippines, Malaysia and India.

We can draw a few lessons from my experience with CEPA these past few years. Firstly, it clearly illustrates how Filipino researchers can make significant contributions to global issues such as climate change, despite the natural tendency among us to focus on primarily local concerns. After all, when it comes to climate change mitigation, every ton of CO₂ released into the atmosphere causes as much harm to the Philippines regardless of where it comes from. Following a similar line of reasoning, research done in the Philippines which is widely disseminated globally, and which helps reduce CO₂ emissions in other countries, will actually be good for the Philippines in the long run. Secondly, the field of chemical cybernetics, which has in fact been around for more than half a century, has yet to be recognized as integral to the chemical engineering discipline in this country. Unfortunately, that in itself is an indicator of the relative scientific and technological backwardness of the Philippines. This is an issue that has been addressed by many other contributors to the Star Science column over the years, and the only true solution is to invest more seriously in research. Lastly, one of the happy lessons I have gained from my experience with CEPA is how the Internet has truly made the world a much smaller place. It is particularly amazing how it enables me to collaborate with like-minded colleagues whom I meet face to face only once every year or so (especially in my discipline, where researchers work mainly with concepts and models); how I am able to access state-of-the-art information without even leaving my desk; and how I, in turn, can share my own ideas with the rest of the world.

(To be concluded)

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Prof. Raymond R. Tan is a university fellow and full professor of chemical engineering at De La Salle University. He is also the current director of that institution’s Center for Engineering and Sustainable Development Research (CESDR). He is the author of more than 70 process systems engineering (PSE) articles that have been published in chemical, environmental and energy engineering journals. He is member of the editorial boards of the journals Clean Technologies and Environmental Policy, Philippine Science Letters and Sustainable Technologies, Systems & Policies, and is co-editor of the forthcoming book Recent Advances in Sustainable Process Design and Optimization. He is also the recipient of multiple awards from the National Academy of Science and Technology (NAST) and the National Research Council of the Philippines (NRCP). He may be contacted via e-mail ([email protected]).