E2695 separation module

All the pretreated coffee waste samples along with their native counterpart were subjected to compositional analysis by following two stage acid hydrolysis according to the National Renewable Energy Laboratory (NREL) protocol (Sluiter et al., 2005) . In brief, the coffee waste samples were hydrolysed in 72% H 2 SO 4 at 30 °C for 60 min. The mixture was then diluted to 4% by adding deionised water and autoclaved for 60 min. The solids were filtered using a filtration crucible and dried at 105 °C for 48 h to remove all the moisture content. The dried solids were then burned in blast furnace for 24 h at 595 °C to obtain acid insoluble lignin. The acid soluble lignin content in the liquid was determined using spectrophotometry at 205 nm. The reducing sugar concentration in the hydrolysate was estimated by dinitrosalicylic acid (DNS) method (Miller, 1959) . The identification and quantification of monosaccharides were done on an Alliance HPLC (Waters, e2695 Separation module) using a Rezex ROA-Organic acid H+ (8%) column, (350 x 7.8 mm; Phenomenex, UK) with 5 mM H 2 SO 4 as the mobile phase at 65 °C maintaining a flow rate of 0.6 ml/min (Jaiswal et al., 2012) .

Raw and pretreated SCW were subjected to compositional analysis by following two-stage acid hydrolysis according to The National Renewable Energy Laboratory (NREL) protocol (Sluiter et al., 2005) . The reducing sugar concentration in the hydrolysate was estimated by dinitro salicylic acid (DNS) method (Miller, 1959) . The presence and quantification of monosaccharides, organic acids and any inhibitors in the form of furfural and hydroxymethylfurfural was done on an Alliance HPLC (Waters, e2695 Separation module) using a Rezex ROA-Organic acid H+ (8%) column, (350 x 7.8 mm; Phenomenex, UK) with 5 mM H 2 SO 4 as the mobile phase at 65°C maintaining a flow rate of 0.6 mL/min (Jaiswal et al., 2012) .
The percentage recovery and percentage removal were calculated using the following formula:
% recovery = W pre / W raw x 100 % removal = 1 -% recovery where, W pre and W raw are the weight of the corresponding component (cellulose, hemicellulose and lignin) in pre-treated and raw SCW (g) respectively (Ma et al., 2015) .