- As free monsaccharides - (e.g. xylose, mannose etc.) in solution.
- As oligosaccharides - i.e. in solution but not fully hydrolysed and instead
present in short chains of sugars, known as oligosaccharides.
- As sugar degradation products - the pre-treatment conditions may have further-degraded the sugars to products such
as levulinic acid, furfural and formic acid.
We have a number of analysis packages that allow for detailed characterisation of the liquid outputs from biomass conversion
processes.
(1) The Starting Feedstock
(2) The Liquid Product from Pre-treatment
(3) The Solid Residue from Pre-treatment
While it is likely that most of the conventional biomass extractives will have been removed in the pre-treatment, it is still necessary in many cases to undertake extractives removal of the solid residue from pre-treatment prior to undertaking its lignocellulosic analysis. This is because this residue may contain some of the liquid fraction sorbed onto its particles. The sugars and sugar-degradation products will be retained and concentrated on these particles if the sample is dried and may still be retained even if the sample is washed. Hence, if they are not removed prior to hydrolysis, these sugars may be assumed to come from lignocellulose, giving a false impression of the efficiency of the pre-treatment.