Boreskov Institute of Catalysis SB RAS, Novosibirsk, Russia

OP-2-3CELLULOSE HYDROTHERMAL CONVERSION PROMOTED BYHETEROGENEOUS BRØNSTED AND LEWIS ACIDS: REMARKABLEEFFICIENCY OF SOLID LEWIS ACIDS TO PRODUCE VALUABLEMOLECULESNadine Essayem 1 , Flora Chambon 1 , Franck Rataboul 1 , Amandine Cabiac 2 ,Catherine Pinel 1 , Emmanuelle Guillon 21 IRCELYON, Institut de recherche sur la catalyse et l’environnement de Lyon, CNRS,UMR 5256, 2 avenue Albert Einstein, F-69626 Villeurbanne, France2 IFP-Lyon, BP 3, F-69360 Solaize, FranceIntroductionOver the past few years, the transformation of cellulose into valuable organicchemicals has attracted a growing interest. Indeed, cellulose is a widely availableand non edible polysaccharide, which makes it a promising resource for theproduction of bio-products and bio-fuels. Liquid acids catalyzed hydrolysis ofcellulose is a process known for more than 80 years. This process presentdrawbacks as a poor selectivity, problems of corrosion and production of largevolume of waste acidic water. Recent studies reported the feasibility of cellulosedepolymerization by mean of solid Br∅nsted acids. In particular, sulfonated carbonbased catalysts were reported to be active in the depolymerization of grindedcellulose. The present study reports investigations of hydrothermal conversion ofcrystalline cellulose, aimed to compare the efficiency of solid Br∅nsted acids to solidLewis acids.Results and DiscussionIn this study, the results of cellulose hydrolysis in hydrothermal conditions, thatmeans in the absence of solid catalysts were used as a reference experiment.Indeed, in a previous study, we have shown that crystalline cellulose may besignificantly depolymerised in hydrothermal conditions, depending on temperatureand duration conditions; at T=190°C, in the absence of solid catalyst, a conversion of35wt% was achieved after 24 h of reaction and glucose and HMF were detected onlyin poor yield [1]. It was shown by combining HPLC, TOC and MALDI TOFF analysisthat mainly water soluble oligosaccharides/polymers were formed (Figure 1). In thepresence of pure Br∅nsted catalysts such as an acidic cesium salt oftungstophosphoric acid or sulfonated carbon, the extent of cellulose depolymerizationwas not changed. However, the product distribution was deeply modified; theproportion of water soluble polymers was improved at the expense of the pool of44