Co-gasification of Plastic and Biomass Waste

Joshua J. Cullen, The University of Western Ontario

Abstract

Gasification technologies have been considered as viable avenues for diverting mixed non-recycled plastic waste landfilling. The main objective of this work was to investigate CO₂ assistedair gasification with mixed plastic and biomass. High-density polyethylene was co-gasified with Douglas fir in different volumes of CO₂ in a semi-batch updraft gasifier. These tests were done in a thermogravimetric analyzer (TGA) to compare the gas, tar and char products of the gasifier with the TGA data. The injection of 10 and 20% CO₂ in air gasification with an air to fuel ratio of 0.3 improved carbon conversion from the tar to the gas phase by 20 and 28 carbon wt% respectively. Injecting CO₂ was an effective moderator for the H₂/CO ratio, beneficial for tar reduction and a key contributor to the energy density of the syngas. From these tests, synergies from the mixed feedstock were identified and discussed for future work.