This minireview discusses the use of zeolites as catalysts in all stages of lignocellulose biomass (LCB) valorization process. A summary of some synthesis and characterization methods for zeolitic materials is provided. Utilization of various active sites of zeolites is explored with the focus on Brønsted and Lewis acid sites and the importance of hierarchical structures in the processes involving bulky biobased molecules. Zeolites modified by top-down methods, specifically desilication with various basic reagents, are good candidates for applications in LCB valorization. Some novelty methods such as a dry milling for incorporating metal nanoparticles into zeolite structure are mentioned. An overview of studies utilizing zeolites in processes such as catalytic pyrolysis of LCB, acid-catalyzed hydrolysis and reactions of platform molecules (ethanol, furans, glycerol, bio-hydrocarbons, lactic acid, succinic acid, levulinic acid, sorbitol, xylitol) is discussed. Special attention is dedicated to reactions of biomass-derived alcohols and value-added chemicals produced from them, e.g., esters. The most successful industrial zeolite application—fluid catalytic cracking—is also summarized for comparison. Challenges of zeolite stability in reactions carried out in liquid water conditions, as well as possibilities of catalyst stabilization, e.g., with extra-framework aluminum, or hydrophobization of the surface, are explored.Graphical abstract

Hereby, we applied a previously developed method of zeolite-catalyzed gas phase synthesis of unsymmetric ethers for a homologous compound to previously synthesized cyclopentyl methyl ether (CPME)—cyclopentyl ethyl ether (CPEE). This synthesis utilized two bio-based alcohols as feed—cyclopentanol (CYPol) in a mixture with ethanol. From a tested group of commercially available zeolites (FER, MOR, BEA, Y, ZSM-5) the best CYPol conversion and selectivity to CPEE was achieved with medium-pore ZSM-5. We further used this zeolite to investigate the effect of reaction temperature and Si/Al ratio, as well as stability and recyclability of the catalyst. At optimized reaction conditions, we achieved selectivity to CPEE of 72% at CYPol conversion of almost 90%. High reaction temperatures, as well as high acid site concentrations in zeolite lead to favoring CYPol dehydration into cyclopentene over etherification. The catalyst exhibited high stability and good recyclability by calcination. We achieved comparable CPEE selectivity at CYPol conversion under mild reaction conditions to the previously documented CPME synthesis, which is a novel green solvent that utilizes a toxic reagent (methanol) for its production.