RESUMEN
Lignocellulosic wastes are valuable feedstock in biorefinery thanks to their high sugars content and low level of fibers intricacy. However, their massification is often a limiting parameter in the development of industrial projects. Hence, this study aims to develop an efficient process enabling the conversion of several waste streams within the same process line. Several pretreatment and enzymatic hydrolysis parameters were firstly evaluated with Old Corrugated Cardboards (OCC) as a model substrate. A chemical free pretreatment followed by an enzymatic hydrolysis (Cellic Ctec 3 enzymatic cocktail at 0.06 g of cocktail per g of Total Sugars (TS)) efficiently depolymerized OCC into monomeric sugars (0.50 g/gTS) consequently fermented into ethanol (0.24 g/gTS). Then, the suitability of this process was validated for sugars production from Pulp and Paper (P&P) sludge (0.48 g/gTS), sieved toilets papers (0.40 g/gTS), the Organic fraction of municipal solid waste (0.37 g/gTS) and Waste Wood B (0.08 g/gTS).
Asunto(s)
Lignina , Azúcares , Fermentación , Lignina/metabolismo , Residuos Sólidos , Xilosa , HidrólisisRESUMEN
In this study, the production of lactic acid from food waste in industrially relevant conditions was investigated. Laboratory assays were first performed in batch conditions to determine the suitable operational parameters for an efficient lactic acid production. The use of compost as inoculum, the regulation of temperature at 35 °C and pH at 5 enhanced the development of Lactobacillus sp. resulting in the production of 70 g/L of lactic acid with a selectivity of 89% over the other carboxylic acids. Those parameters were then applied at pilot scale in successive fed-batch fermentations. The subsequent high concentration (68 g/L), yield (0.38 g/gTS) and selectivity (77%) in lactic acid demonstrated the applicability of the process. To integrate the process into a complete value chain, fermentation residues were then converted into biogas through anaerobic digestion. Lastly, the experiment was successfully replicated using commercial and municipal waste collected in France.