Yields of Fermentable Sugars and Ethanol Co-Products Using the Avap Process

Production of high-value co-products from wood pulping could increase the global competitiveness of the US pulp and paper industry. Ethanol is a co-product with a great potential to replace foreign petroleum-based transportation fuels, reduce greenhouse gas emissions, and boost rural economic development. The objective of this study was to perform laboratory scale experiments to determine sugar and ethanol yields from pulping of softwood and hardwood species from the north central forest region of the US.

In this study, pine and birch samples were processed using the AVAP (American Value Added Process) technology. Process conditions were altered to investigate their affect on pulp, sugar and ethanol production. For pine, ~11 wt% of dry wood was converted into monomer sugars, with the remainder as pulp product. For birch, ~9% was converted to monomer sugars.

The sugars produced were also used in the fermentation of ethanol. The over all yield of ethanol from the dry pine was calculated to be ~3.7 wt%. Calculations indicate that if all oligomer sugars and pentose sugar monomers are converted to ethanol and theoretical yield, as much as 10% of the woody biomass can be recovered as ethanol.