Chemistry and Energy Lecture

Salutations,

Today I visited the Open University to attend a lecture titled : ‘Chemistry and Energy: from Steam to Nuclear Power.’ It was presented by Dr Mark S. D. Read from the University of Birmingham who has a fellowship from the Royal Society of Chemistry.

Firstly we discussed the various states of matter and transformations from one state to another; we were even shown a demonstration of dry ice to help us understand the concept of sublimation. The salient piece of information we had to take away from this is that liquid expands by a factor of 1700 when it evaporates to become a gas, and this is what powered the rise of the steam engine and electricity as we know it.

The premiering steam engine was pioneered in 1712 by Thomas Newcomen and it used a counter-intuitive mechanism to produce power. Cold water was pumped into a chamber filled with steam which condensed the volume. In turn this led to a piston being drawn downwards and a lever rising. The downfall of this invention was that it relied on pressure differences and because the pressure varies on Earth from day to day, the mechanism was rather unreliable.

Fortunately, Boulton and Watt came up with a much more efficient design which used steam to push a piston, a much more intuitive design mechanism. Their design has been modified and improved over time into what we now call the modern energy grid, which uses heat to turn water into steam, which turns a turbine which then, in turn turns a generator.

Next, we were wowed by a fabulous display. The lecturer used methanol to produce steam via the following equation:

2CH3OH(l) + 3O2(g) – > 2CO2(g) + 4H2O(g)

He did this by swilling a small volume of methanol in a water container and then emptying the excess liquid so we were left with vapourised methanol. The interior of the container was then set on fire and we watched in awe and wonder as a huge blue and purple flame surged upwards from the container. This demonstrated to us how gases expand when heat is applied to them.

The subsequent topic covered was stars and spectroscopy. Dr Read explained that from stars one may obtain light, energy and elements. The energy is harvested from fusion and fission. Fusion is when two light nuclei are forced to collide, creating a brand new element. Using the equation E=mc^2, it is obvious to us that as the products are slightly lighter than the reactants, lots of energy must have been released from a tiny mass. If we could harness this energy, the fuel crisis hampering our everyday lives could be forgotten completely. In contrast, fission is the splitting of larger nuclei into 2 daughter nuclei which are considerable smaller; and again, as the product is lighter, energy is released in the reaction. This may be used to heat water and power the grid, but it is for my generation to find the solution to a problem that needs an answer more than ever, as fossil fuels’ time comes to an end.

On a separate note, we were shown how spectroscopy can be used to detect whether a star is being born or dying. We watched a fun and interactive practical, a flame test, in which I learnt that boron is green in a flame. When a spectroscopy is taken, the colours that are absent from the spectrum indicate whether a star is being born or dying because heavier elements will not be present in a star which has just entered existence, as fusion will not have taken place. This showed us the practical applications of our lessons and really did demonstrate that chemistry is a useful subject which is needed in many realms of the everyday world.

Although I had previously learned about superconductors in physics, I was stunned to see metal levitating on a magnetic field. The superconductor has the formula YBa2Cu3O6 and it causes magnetic field lines to be deflected, thus allowing the levitation of other metals. However, this is only currently possible at extremely tow temperatures close to absolute zero, but Dr Read believes our generation may have the answers to find a superconductor at room temperature, which would allow us to use this technology for all sorts of new technology such as frictionless train tracks.

Finally, we compared energy usage from 1971-2009 and this showed an unsurprising decrease in coal use. However, it also demonstrated that we are using less oil since the price of it has increased. Furthermore, I found it almost comical how there was a spike in gas usage when the North Sea gas was discovered in the 1980s, and what surprised me was that nuclear power has had the same usage throughout, and this will actually decrease when all the nuclear power stations start to be decommissioned soon. This will lead to a 20% shortfall in electricity so without an increase in renewables, we are essentially going back to the dark ages.

Dr Read discussed the possibility of hydrogen fuel cells which are non polluting as their only product is water. However, we must consider that this hydrogen actually originates from electrolysis and so electricity is still used in the process. Can any fuel really be fossil fuel free?

Maybe you or I could solve some of these problems that our society faces, or perhaps our role will be instrumental in finding the fuel of the future! I would like to thank Dr Read for this inspiring talk, and hope to meet him again one day to discuss these topics in more detail.

Keep your eyes peeled for my next post,

Lara

 

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