Screening of sugars and phenolics released during pretreatment of miscanthus, maize and sugar cane bagasse for potential added value products from c4 crops

The viability of cellulosic fuels hangs on the reduction of the costs involved in the conversion processes. An approach to reach a realistic cost for conversion of biomass into large volumes/low cost products is by identifying added value products that can be obtained during the production of biomass derived fuels. This biorefinery concept involves the benefits of reducing the cost of the overall process, replace petroleum derived materials and chemicals, and reduce waste streams. Pretreatments have been considered for a long time as the key to take the biochemical conversion of biomass to levels which are compatible with industrial applications.  A great deal of research has been put into the development of different pretreatments over the last 10 years and the literature is rich in diverse and creative approaches to increase the efficiency of pretreatments in terms of increased fuel production after fermentation. An interesting new approach to evaluate pretreatmens is the preservation of the valuable chemicals in the pretreatment liquors in order to add value to the process from products obtained by fractionation of the biomass. In the present work we characterise the sugars and lignin derivatives present in the pretreatment liquor of maize, miscanthus and sugar cane bagasse under a range of acid and alkaline pretreatments. This allows a detailed picture of the conditions necessary for favouring a certain type of compounds and also a horizontal comparison of the compounds generated between species.