Optimising the (Microwave) Hydrothermal Pretreatment of Brewers Spent Grains for Bioethanol Production

Figure 3

Design Expert 3D response surface models showing the effects of the factors (i) % solids loading (w/v) and (ii) reaction time (min) during 200°C pretreatment of BSG (temperature as previously optimised) on the resultant sugar concentrations liberated directly into the pretreatment hydrolysate (g/L). (a) Glucose (: 0.84), (b) xylose (: 0.96), (c) 5-hydroxymethylfurfural (: 0.98), and (d) furfural (: 0.81). Autohydrolytical pretreatment utilized a Monowave 300 microwave synthesis reactor with G30 vessels (Anton Parr).

(a) Glucose

(b) Xylose

(c) 5-Hydroxymethylfurfural

(d) Furfural