Enhanced hydrogen-rich gas production from waste biomass using pyrolysis with non-thermal plasma-catalysis

A pyrolysis-non-thermal plasma-catalytic system for the increased production of hydrogen-rich gas from waste biomass has been investigated. Plasma processing of the hydrocarbon pyrolysis gases produced a marked increase in total gas yield with plasma-catalysis producing a further modest increase. The product gases were mainly composed of H₂ , CO and CO₂ , which were all increased under plasma and plasma-catalyst conditions. For example, H₂ yield increased from 1.0 mmol g −¹biomass in the absence of plasma to 3.5 mmol g −¹biomass with plasma and to 4.0 mmol g −¹biomass with plasma-catalysis. In addition, in the absence of plasma, the hydrocarbon tar content in the product gas was 420 mg m −³ , but, for non-catalytic plasma conditions, this was reduced to 325 mg m −³ and for plasma-catalytic steam reforming, the tar hydrocarbons were markedly reduced to 150 mg m −³ . The effect of increasing input power for the plasma processing (no catalyst) showed a large increase in total gas, H₂ , CO and CO₂ yield and corresponding decrease in hydrocarbon gas concentration. Plasma-catalysis showed that higher power input had only a small effect on gas yield. Plasma-catalysis was shown to produce lower catalyst coke deposition compared to non-plasma catalytic processing.