Syngas production from polyethylene and biogas in porous media combustion

The production of syngas from biogas (surrogate of CH4/CO2: 55/45 v/v) and polyethylene in a porous media combustion reactor is experimentally studied. The employed setup is novel and has not been studied before. A semi-continuous feed of solid fuel and a constant filtration velocity of the gaseous reactants of 17 cm/s were considered. Temperature, velocity of propagation, and composition of the syngas produced in the combustion waves were registered in a tubular reactor packed with a ceramic foam porous medium and two solid fuel inlets. In the first part of the study, a baseline determined by the filtration combustion of a biogas/air mixture through the ceramic foam at the equivalence ratio (∅) range 0.7≤∅≤1.6, having transient (upstream and downstream) and stationary combustion wave propagation regimes, is established. In the second part of this work, portions of the ceramic foam in two different separated zones are extracted, leaving space for the semi-continuous supply of polyethylene. In this second part the biogas-air combustion was performed only for ∅=0.8 and ∅=1.6. Although the combustion temperature decreased by the presence of polyethylene, it was found that the syngas (both H2 and CO) yield was larger than for the baseline. The highest degrees of conversion to hydrogen and carbon monoxide was reached under the presence of polyethylene, having 45% and 67% for ∅=0.8, and 45% and 60% for ∅=1.6, respectively. These results are very promising and they demonstrate the capabilities of the presented methodology and experimental setup, which should encourage future attempts of applications of the technology.