Influence of the feedstock on catalytic fast pyrolysis with a solid acid catalyst

Abstract

At RTI, we are developing a catalytic fast pyrolysis process with a new solid acid catalyst, the performance of which has been evaluated in a pilot-scale reactor using loblolly pine. More robust technology development requires a deeper understanding of the influence of the feedstock properties of process performance defined by the organic liquid yield and composition. Seven types of woody and herbaceous biomass were tested in a 2.54 cm diameter fluidized-bed reactor. This study shows that the product distribution and biocrude composition vary widely with different feedstocks. The yield of organic biocrude is in the range of 14.0-20.8 wt% for the tested feedstocks. The yields of incondensable gases and carbonaceous solids vary significantly from feedstock to feedstock, which may be because of the variation of the ash content in the feedstock. A feedstock with a higher ash content generates more gases; specifically more CO2 but not necessarily more CO. The chemical composition, which includes lignin, hemicellulose, and cellulose, also affects the biocrude composition and the yield of gases. We also demonstrated a positive correlation between the cellulose content and CO yield and a negative correlation between the hemicellulose content and CO yield.