Integrated Catalytic Process for Cellulose Hydrolysis: A Comparison of Different Pretreatments

The conversion of cellulose into valuable chemicals is one of the most important aspects of the biorefinery concept, the aim of which is to develop integrated processes for the transformation of renewables collected from agricultural, forestry and urban waste into platform molecules. The aim of this work is to compare the performance of metal phosphates catalysts in cellulose hydrolysis, after pretreatment of the biomass with different procedures. The catalysts tested for microcrystalline cellulose hydrolysis were based on Zr/P/O, previously tested in lignocellulose hydrolysis. We compared two different types of pretreatment: a mechanical pretreatment, in which cellulose was subjected to a 48-hours treatment in a high-energy ball mill, and a thermal pretreatment, in which cellulose was autohydrolyzed at 180°C for 1 hour in a monomodal microwave reactor. Results of tests conducted with the Zr/P/O catalyst on cellulose, either as such or after the two different treatments, showed that pretreatments were effective in facilitating the hydrolysis: in particular, with both pretreated celluloses, we observed an important improvement of catalytic performance.