Environmental impact assessment of cascading use of wood in bio-fuels and bio-chemicals

Cascading keeps wood in products for a longer duration and delays the embedded biogenic carbon emission. Carbon is kept out of the atmosphere for longer, giving forests time to sequester equivalent amounts of carbon. The storage period and time needed to sequester the same amount of carbon affect the GWP - an aspect often overlooked in LCA. This study compares alternative wood cascading scenarios producing biochemicals and fuel – to examine the influence of the rate of biogenic carbon flows on the net GWP of cascading systems. GWP decreases with increasing cascade steps. Benefits are higher when considering the temporal information – highlighting that current carbon accounting may underestimate the climate benefit of cascading. The GWP of bio-refinery products depends on their feedstock. GWP is lower when using waste wood, which has served a long time, instead of virgin wood. Benefits enlarge by extending the application lifetimes of these products.