Scalable separation methods for the isolation of monosaccharides in a biorefinery context

摘要: Biorefineries allow for the sustainable production of higher value products from biomass. In addition to bioethanol, they can produce added chemicals and pharmaceutical intermediates isolated component compounds such as sugars. Sugar beet pulp (SBP) is a high volume, low by-product sugar processing with lignin carbohydrate content, making it an attractive biomass feedstock biorefinery processing. The pectin fraction SBP be via steam explosion, which, after complete acid hydrolysis, gives hydrolysate rich in monosaccharides: primarily L-arabinose (Ara) D-galacturonic (GA), some D-galactose (Gal) L-rhamnose (Rha). Isolation these sugars therefore critical step realising integrated, whole crop biorefinery. Currently, little work has been reported on separation utilisation hydrolysates. aim this thesis establish novel, scalable processes isolation monosaccharides crude hydrolysed pectin. Centrifugal partition chromatography (CPC) liquid-liquid technique no solid stationary phase offers alternative traditional resin-based chromatographic techniques. As more easily cope feedstreams Hydrophilic ethanol : ammonium sulphate two-phase systems were examined based monosaccharide coefficients settling times. An aqueous (300 g L-1 ) (0.8:1.8 v:v) system was chosen CPC separations shown capable removing coloured contaminants isolating three fractions single step: Rha, Ara Gal, GA. optimised throughput increased by maximising sample loading. Operation elution-extrusion mode allowed reproducible 100 min without additional column regeneration. process scaled up 250 950 mL providing final 1.9 gmonosaccharides L -1 h using SBP. following purities recoveries main achieved: Rha at 92% purityand 93% recovery; 84% purity 97% GA 96% 95% recovery. Simulated moving bed (SMB) allows continuous multiple columns, improving performance throughputs. neutral Gal performed resins conditions screened columns leading selection Dowex 50W X8 resin Ca2+ form. SMB 8 4-zone 3-zone setups achieved 94% 99% recovery 4.6 synthetic mixture (Ara, Rha). However, equivalent could not which needed pretreatment before SMB. Decolourisation activated carbon able remove losses 15% (w/w) batch demonstrated 50 scale. Anion exchange 1x8 then found dynamic binding capacity 1.31 mmol mL-1 resin. further enable anion achieve satisfactory decolourised hydrolysate. sugars, removal, processed comparable prepared summary, presents two possible paths each their own benefits drawbacks. directly, step. co-elutes stream that only pure. SMB, potential throughputs are higher, however, experimentally mixtures Further or method development would required order hydrolysate, resulting multistep may reduce overall viability. Overall demonstrates feasible approaches preparative scale hydrolysates supports integrated