Finding the Energy in different plastics

The problem I am trying to tackle is plastic pollution. My aim is to find the energy amount in different plastics and to compare it to the energy efficiency when burning crude oil and recycling plastics. I am doing this to stow that it could be of interest to burn plastics and use the fresh hydro carbons from crude oil to make new plastics instead of using large amounts of energy to recycle the existing, used plastics, see Figure 1. I think this is a novel and easy to implement approach to tackling the problem of plastic pollution.
This fits very well with the sustainability and plastics project that we are doing in our school. I soon realised that I did not have a calorimeter available to do the required experiments I intended to perform, to advance my laboratory skills. Therefore, I then started to design and build my own calorimeter preferably in a cheap way relying on available materials. So, I used waste materials (food tins, polystyrene box) to construct a calorimeter of limited complexity. I only ordered heat resistant paint and expanding insulation foam.
When I tested my self-built equipment with ethanol I realised the material I used (Plexiglas and polystyrene) was not resistant enough to heat produced. So, I tried to add a heat resistant mat, instead of the Plexiglas, and polystyrene. When testing this combination, the heat resistant mat cracked, and the polystyrene lid was damaged again, so next I will try to add tin foil underneath the heat resistant mat, to reflect the radiation back into the chamber. However, even with this improvement I fear the calorimeter will not be durable enough to do the planned serial tests.
Regardless the problems I faced, even experimenting with this very limited setup and possibilities I managed to capture 91% of the literal calorific value of ethanol in my first experiment.

Funded by Liverpool (February 2019)