Aromatics from Biomasses: Technological Options for Chemocatalytic Transformations

Bio-based benzene, toluene, xylenes(BTX) can be produced starting from biomasses via several different routes, as shown in Figure 2.1 [1]. Main pathways include (i) pyrolysis or catalytic pyrolysis of lignocellulose fractions; (ii) aqueousphase reforming (APR) of aqueous carbohydrate solutions, followed by catalytic transformations; (iii) Diels–Alder reactions between furanic compounds, the latter having been obtained from monosaccharides, and ethylene; this approach has several variants, with either differently functionalized furanics or dienofile compounds; and (iv) dimerization and dehydrocyclization of bioisobutanol. The latter two pathways are aimed at the synthesis of p-xylene, whereas the former two produce mixtures of aromatics, which can be either fractionated to single compounds or used as a blend for fuels. The reaction involving the Diels–Alder reaction is not discussed here, being dealt with in the chapter devoted to reactions for C–C bond formation