초록
<P><B>Abstract</B></P> <P>Ethanol production using waste biomass represents a very attractive approach. However, there are considerable challenges preventing a wide distribution of these novel technologies. Thus, a fractional-factorial screening of process variables and <I>Saccharomyces cerevisiae</I> yeast inoculum conditions was performed using a synthetic fermentation media. Subsequently, a response-surface methodology was developed for maximizing ethanol yields using a hemicellulosic solution generated through the chemical hydrolysis of steam treatment broth obtained from residual softwood biomass. In addition, nutrient supplementation using starch-based ethanol production by-products was investigated. An ethanol yield of 74.27% of the theoretical maximum was observed for an initial concentration of 65.17g/L total monomeric sugars. The two-step experimental strategy used in this work represents the first successful attempt to developed and use a model to make predictions regarding the optimal ethanol production using both softwood feedstock residues as well as 1st generation ethanol production by-products.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 8 factors concerning yeast, nutrients and process parameters were investigated. </LI> <LI> Yeast inoculum, pH and nutrient availability were determined the most significant. </LI> <LI> Process modeling was performed and optimization scenarios were predicted. </LI> <LI> A maximum of 74.27% of hemicellulosic ethanol yield was produced. </LI> <LI> Optimization confirmations and bioreactor scale-up were performed. </LI> </UL> </P>