The impact of reaction temperature (120–200°C) and reaction time (1–10 min) at various solids loading during 1% HCl acid catalysed hydrothermal pretreatment of BSG on cellulose concentration (expressed as glucose; mg sugar per g solid residue) of the remaining pretreated solid residue after complete acid hydrolysis. (a) 30% solids loading, (b) 40% solids loading, and (c) 50% solids loading. Data are the mean ± SD of three replicate measurements. 1% HCl hydrothermal pretreatment utilized a Monowave 300 microwave synthesis reactor with G30 vessels (Anton Parr).