What can sustainability learn from chemical engineering?

As a chemical engineer, during my thermodynamics class, I studied the concept of activation energy, which is the minimum energy required by a chemical system of potential reactants to start a chemical reaction. Furthermore, for us to fully understand the concept, our teachers made us imagine an invisible barrier separating reactants from their truly stable state as products. Then, they compared them with the barriers athletes need to jump as part of a race: the lower the barrier the less effort necessary to jump over it and the faster the athlete can run towards the next barrier. When I asked about how to do it, how to decrease the activation energy of a system, they replied that even though the activation energy was intrinsic to the system, external conditions could decrease it either by affecting the amount of energy required or by increasing the initial internal energy of reactants. This is how the concept of catalysts and the ideas of the possibilities to “play” with the external environment of a system were introduced to me.


Now, maybe you can wonder how is this related to sustainability, and is simple: what if he applied the same concept of activation energy to a socio-technical system to see what possibilities can be released. Firstly, it would be necessary to redefine activation energy as the amount of effort required for a technical system to go from an initial state towards a sustainable (and more stable) one. Sighted from such perspective, it seems like something difficult to compute and useless for practical matters. Consequently, now it is time to remember that activation energy is related to a combination of potential reactants, so, it would be easier to relate the concept not to the entire system but to a piece of it. Let use an example: let us use the activation energy to help somebody to start a healthy lifestyle.


Laura wants to start living a healthier life, for such reason she wants to start running every morning and eating more fruits every day. Moreover, she wants to save water and to manage her waste better. However, she is somewhat lazy and really hates to wake up early to exercise. So, how can the activation energy concept be applied here? The answer is quite simple:

  1. To exercise every morning: The activation energy would be the effort required for her to wake up, change her clothes, brush her hair, brush her teeth, look for her keys and water, and put on her sport shoes. Solutions: Go to bed with your sports clothes on, leave the shoes, keys, brush, water and a fruit in the table next to the bed for easy access, and set an alarm with energetic music that encourage movement. Expected results: As less effort is required for Laura to go running in the morning, it is more likely that she will do it regularly and to become part of her everyday routine.
  2. To eat more fruits: The activation energy would be the effort required for her to buy the fruits every day, peel the fruits or wash them, to cut them and to access them. Solutions: Go to the market every week and prepare a Tupperware with chopped fruits to have in the refrigerator while cooking dinner for the next day. Expected results: As less effort is required for Laura to access fruits in the way she enjoys eating them, it is more likely she will do it in a regular basis.

Now, just to check if you understood the concept, try to calculate the activation energy and possible solutions for Laura to improve her water and waste management, I am sure you can do it!


Furthermore, I believe is possible to perform a similar analysis when trying to implement sustainable ideas, identifying the efforts needed to start an action and find ways to decrease them,this methodology has taught me to think outside the box and, most of the time, I have realized that a simple change in our routine can make a life-longing difference. The implementation of the activation energy and the seek for catalysts for sustainable transitions is the main learning point chemical engineering can pass to sustainability, but I am sure that, when looking closely, the same can be done from a diverse set of disciplines in order to improve the success chances of sustainable initiatives. 

María José Galeano Galván

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