sábado, 24 de junio de 2017

Why chemists — not just economists — are key to a circular future

Today's professional chemical engineers accept responsibility for avoiding or abating pollution of the environment by the process industries.

But the profession, of which I am proud to be a part, should play a more fundamental role in sustainability. We need a complete rethink of the way we manage and use resources, including energy and land, as well as materials.

Chemical engineering must contribute to this change as a way of thinking, not just as a technological discipline. We can see this from the way chemical engineering has developed and how it continues to evolve.

Chemical engineering originated in the closing years of the 19th century with the work of George E Davis. Davis worked in Manchester's early chemical industry. He delivered some of the first lectures on chemical engineering and published them in 1901 in his seminal work, "The Handbook of Chemical Engineering."

Davis' thinking impacted well beyond Manchester's fledgling chemical industry and resulted in the emergence of a new field, encompassing both chemical processes and mechanical equipment. The discipline grew into a profession and by 1922 the Institution of Chemical Engineers (IChemE) had emerged, with a mission to advance the profession.

Chemical engineering is concerned with managing flows and transformations of materials and energy in industrial plants. It has become the engineering discipline of the process industries, which include chemicals, petrochemicals, plastics, water, energy, pharmaceuticals and food. Simply put, chemical engineers turn raw materials into products, whereas mechanical engineers turn products into devices and machines.

It is a general and systematic way of approaching problems based on integrating fundamental scientific principles. This includes thermodynamics — the branch of physical science that deals with laws governing the processes of the transformation of energy. Thermodynamics is essential because it defines what is possible. Few economists have any awareness of thermodynamics. One factor that has led to the degradation and contamination of our planet is that conventional economics does not recognise thermodynamic limits.

Chemical engineering is a key discipline contributing to industrial ecology. Industrial ecology is "the study of the flows of materials and energy in industrial and consumer activities, of the effects of these flows on the environment, and of the influences of economic, political, regulatory and social factors on the flow, use and transformation of resources." Even the basic tools used in industrial ecology, including life cycle assessment and material flow accounting, are a combination of chemical engineering fundamentals.

But why is this important right now?

Because anyone with their eyes and ears open — not including those who deny that climate change is happening or that species are disappearing at a rate like those in great extinctions of the geological past — knows that our planet is heading into crisis. Anyone who feels a responsibility to future generations knows that humanity has to change its behavior, and that incremental change in the way we make and consume things will not be enough.

It may come as a surprise to suggest that a branch of engineering can make an essential contribution to social and economic theory, but there are many examples to illustrate this. 

There is a growing interest in the "circular economy" as a way to improve resource efficiency. The circular economy is a topical example of why the chemical engineer's way of thinking has so much to offer. A circular economy is an alternative to a traditional linear economy — make, use, dispose — to keep resources in use for as long as possible, extract the maximum value from them whilst in use, then recover and regenerate products and materials at the end of each service life.

Although some advocates of the circular economy still interpret it as simply increasing recycling rates, it is clear to anyone with a chemical engineering background that the key to resource efficiency is to get best value from materials and products in use — the stock — and reduce their flow through the economy. The most important change is therefore to increase the service life of goods in use — what we chemical engineers term the "residence time."

This simple realisation still eludes those who focus on recycling as the way to promote the circular economy, although fortunately it is recognized in the Waste and Resources Action Programme (WRAP) in the U.K., in the EU Circular Economy Action Plan and in the work of the Club of Rome. The conclusion is so obvious that it was highlighted six years ago in a short article in the Chemical Engineer magazine (PDF) in 2011.

If chemical engineering thinking had been applied from the outset, a proper understanding of what the "circular economy" really means and needs would have emerged much earlier. 

Deliberately extending product life represents the kind of system revolution that goes beyond incremental change.

Some implications are worked out in a Walter Stahel's important book, "The Performance Economy." Extending product life requires a complete change in business thinking and a shift from the paradigm that has dominated since the industrial revolution. It is consistent with a move towards selling services rather than material products; towards leasing rather than outright sale of products; towards re-engineering used products rather than throwing them away or recycling.

Re-engineering requires use of labor rather than energy or raw materials. This means improving the energy productivity of the economy, but at the same time reducing "labor productivity." However, labor productivity is a profoundly perverse indicator of economic performance. How do we reconcile improving labor productivity with the need to increase skilled employment? Different indicators are needed, describing, for example, labor use per unit of material or energy throughput. 

This line of thinking runs contrary to conventional economic thinking — which is not to say that it is misconceived. New thinking must be developed with input from different disciplines, not just the economists who tend to dominate this debate. 

I urge chemical engineers, and all those involved in the design and operation of manufacturing processes, to rethink what we mean by a sustainable economy. The dominance of economics must be toppled. The laws of thermodynamics are hard-wired into the universe, whereas economics "laws" are written on paper and paper is a product made by humans.

It's time to speak up for thermodynamics. The future of our planet depends on it.


No hay comentarios:

Publicar un comentario