2024 AIChE Annual Meeting

Waste Plastics to Fuel: Analytical Techniques to Classify Plastics and Evaluate Fuel Quality

Plastic is not infinitely recyclable, but little end of life processing has been developed outside of landfilling. The Plastics to Fuel project aims to change this standard and create an alternative use for plastic once it reaches the end of its life cycle. To do this, the Plastic to Fuel project starts with an unknown mixed plastic sample, characterizes it through Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), and Fourier-Transform Infrared Spectroscopy (FTIR). Then, using a single step slow pyrolysis kiln reactor, a liquid carbon fuel (diesel) is produced. By performing Gas Chromatography (GC), and Nuclear Magnetic Resonance (NMR) on the product, a comparison can be made to a model HDPE pyrolysis diesel, as well as with farm (red) diesel.

Through these analysis methods, it has been shown that the pyrolysis diesel is comparable to commercial farm diesel fuel. However, if fossil fuel-based electricity to power the reactor it diminishes the energy savings and makes it necessary to have a source of electricity. In summer 2024 the project team tested the pyrolysis kiln reactor powered by solar panels supplied by the OSU Solar trailer provided by the OSU Sustainability Coalition. The results were comparable to those obtained with conventional electricity sources.

Moving forward, the focus will be to capture and analyze the off-gas (< C6) to close the mass balance and determine the process efficiency. Recirculating the off-gas to supplement heating the kiln air will also be studied. The ultimate goal of the project is to provide a low-cost, simple to operate and maintain pyrolysis reactor to underserved, island, and rural communities that struggle with disposing of their plastics and have a need for diesel fuel for their tractors, boats , generators, etc. With further development, this project has the potential to reduce waste in landfills and improve the quality of life while also reducing local cost for fuel in rural communities.