"Plastic - A Plague Turned to Provider."

ASE 2016

Isabelle Quaye
Accra, Ghana

During each YYGS session, students had the opportunity to share inspiring personal stories or ideas with the group in the YYGS Speakers Series. This is one such project.

The raging battle against plastics over the years has been a never-ending war with little or no way to cost-effectively dispose of the non-biodegradable matter. Recycling, Re-use and Incineration are the few methods that have been employed to eliminate plastics, but they have been less than successful

Energy crisis in several countries in sub-Saharan Africa have lead to long periods of blackouts and a collapse of several industries in these countries. Ghana in particular has faced several setbacks economically and socially due to the power crisis. Having two problems that appear seemingly unrelated plaguing a country for decades has several setbacks other than those mentioned above. The problem is that, by trying to solve one problem, we often end up creating a dozen others, so the ultimate goal is to create zero or net problems.

The main idea of this blog is to introduce a concept that could potentially revolutionize energy and plastic disposal. We turn plastics into energy. The idea sounds out of the world and impossible as well as expensive. But the basis of most plastics particularly polythene is carbon, hydrocarbons. If we are able to successfully separate these two efficiently, we can hopefully turn a potential threat to a lucrative fuel and energy source.

Polythene, a polymer of ethene/ethylene, is an LDPE (Low density Polyethylene) that is often used for plastic bags at supermarkets and is a common packaging material in Ghana. It is made up of several long chains of alkenes such as ethene, octene and hexene. To be able to effectively convert these hydrocarbons to either gasoline, diesel or even possibly pure hydrogen will be a groundbreaking discovery. This is due to the fact that it could provide substantial sources of fuel for energy as well as a profitable avenue for the disposal of plastics we have no further use for.

The bonds in polythene are extremely strong, requiring a lot of energy to break the bonds. Around 179, 783J of energy are required to melt 1 kilogram of polythene. However, the method I am proposing is to use energy from sunlight to heat up the polythene in order to break the bonds, the first step in actually separating out and isolating any product. Concentrating solar rays can cause temperatures to rise to almost 500 degrees Celsius providing optimum energy to melt the plastic. The bonds in the polythene, stimulated by contact with UV light, break. The reaction occurs in anoxic conditions in order to ensure that no side reactions that are unaccounted for do not occur. A mixture of Aluminium Oxide and Silicon oxide are used as a catalyst. Aluminium oxide is a highly stable compound and so is silicon oxide. Both also have high melting points and boiling points, making them suitable for the process. I must however say, that the full chemistry is still unknown to me.

Although, this is not a fully constructed idea, I am more than confident that research into this area is promising. A recent experiment conducted by some Indian scientist saw plastics being converted to paraffins and olefins (two common fuel sources) showing the immense potential of this avenue of plastic disposal. By varying temperature, pressure and other conditions, it may be possible to produce pure hydrogen and even pure carbon in the form of a valuable allotrope such as diamond. The prospects are unimaginable but exciting!

The importance of this process is crucial as pointed out by an article released by the Cambridge-MIT Institute under the Impee Project:
"Many plastic products are reaching the end of their lifecycle, forming non-biodegradable mountains of waste plastic."

Despite recycling being an attractive avenue, frequent recycling will end up rendering the plastic useless and a waste. Research into this area is an exciting new field and I am even so more excited to participate.

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