Pyrolysis of Mixed Solid Food, Paper, and Packaging Wastes 2008-01-2050

Pyrolysis is a very versatile waste processing technology which can be tailored to produce a variety of solid, liquid and/or gaseous products. The pyrolysis processing of pure and mixed solid waste streams has been under investigation for several decades for terrestrial use and a few commercial units have been built for niche applications. Pyrolysis has more recently been considered for the processing of mixed solid wastes in space. While pyrolysis units can easily handle mixed solid waste streams, the dependence of the pyrolysis product distribution on the component composition is not well known. It is often assumed that the waste components (e.g., food, paper, plastic) behave independently, but this is a generalization that can usually only be applied to the overall weight loss and not always to the yields of individual gas species. The current paper will present results on pyrolysis of various mixtures of plastic (polyethylene), food (composite of 40% assorted dried food, 30% flour, 10% milk powder, 7% egg powder, 4% potato powder, 3% gluten, 3% corn starch, 3% sugar), and paper (cellulose). In addition to the model mixed food waste sample, additional runs were done with actual restaurant food waste after it was dehydrated. The paper will include results for major product yields (char, gas, water + oil, carbon) as well as the gas composition (H₂, CO₂, CO, CH₄, C₂H₄, and NH₃), and the char composition and char reactivity.