Biorefineries, which utilize lignocellulosic biomass as renewable energy source and sustainable carbon feedstock, are a promising solution to alleviate the excessive dependence on the depleting fossil resources and address climate change and other environmental problems. Owing to the recalcitrance and over-functionalized nature of biomass, the conversion of biomass into desirable products requires a series of complex deconstruction, catalytic conversion, separation and purification processes. In the biorefinery roadmap, 5-hydroxymethylfurfural (HMF) stands out as a bridge connecting biomass raw materials to alternative fuels, chemicals and materials, which can displace petroleum-derived products. This review describes the recent advances in the design and development of catalytic systems for the conversion of biomass and their constituent carbohydrates to HMF via hydrolysis, isomerization and dehydration reactions, and the upgrading of HMF towards polymer monomers, fine chemicals, fuel precursors, fuel additives, liquid fuels, and other platform chemicals via hydrogenation, oxidation, esterification, etherification, amination and aldol condensation reactions, with emphasis on how the catalysts, solvents and reaction conditions determine the reaction pathway and product selectivity. We also attempt to provide a conceptual framework on how to evaluate the actual reaction efficiency, reusability, and economic and technical feasibility of different catalytic systems and highlight the key research challenges to be addressed.

With the aggravation of the energy crisis and environmental problems, biomass resource, as a renewable carbon resource, has received great attention. Catalytic fast pyrolysis (CFP) is a promising technology, which can convert solid biomass into high value liquid fuel, bio-char and syngas. Catalyst plays a vital role in the rapid pyrolysis, which can increase the yield and selectivity of aromatics and other products in bio-oil. In this paper, the traditional zeolite catalysts and metal modified zeolite catalysts used in CFP are summarized. The influence of the catalysts on the yield and selectivity of the product obtained from pyrolysis was discussed. The deactivation and regeneration of the catalyst were discussed. Catalytic co-pyrolysis (CCP) and microwave-assisted pyrolysis (MAP) are new technologies developed in traditional pyrolysis technology. CCP improves the problem of hydrogen deficiency in the biomass pyrolysis process and raises the yield and character of pyrolysis products, through the co-feeding of biomass and hydrogen-rich substances. The pyrolysis reactions of biomass and polymers (plastics and waste tires) in CCP were reviewed to obtain the influence of co-pyrolysis on composition and selectivity of pyrolysis products. The catalytic mechanism of the catalyst in CCP and the reaction path of the product are described, which is very important to improve the understanding of co-pyrolysis technology. In addition, the effects of biomass pretreatment, microwave adsorbent, catalyst and other reaction conditions on the pyrolysis products of MAP were reviewed, and the application of MAP in the preparation of high value-added biofuels, activated carbon and syngas was introduced.

The latest design and development of thermal-catalytic strategies are sorted based on the active species and types of catalysts. The ongoing challenge and opportunities have been concluded.