State-of-the-art advances and perspectives in the separation of biomass-derived 5-hydroxymethylfurfural

Effectively converting renewable biomass resources into valuable chemicals is a very promising and fascinating approach to lower the overreliance on non-renewable fossil resources. Among numerous biomass-derived chemicals, 5-hydroxymethylfurfural (HMF) is particularly attractive and widely thought to be a momentous building block, because it simultaneously contains three reactive groups (including an aldehyde group, a hydroxy group and a furan ring) and can be further transformed into a wide variety of high-value derivatives. For a long time, considerable efforts have always been concentrated on developing high-efficiency catalytic systems for the production of HMF. However, separating HMF from various catalytic systems, which is very significant for its subsequent transformation and application, has not yet received sufficient attention. Meanwhile, to the best of our knowledge, a special and systematic review is still lacking in this research area. To get more insights into the present research status, this review comprehensively summarizes and discusses the latest advancements on various separation methods of HMF, including extraction, distillation, adsorption and filtration, and emphatically analyzes some important evaluation parameters, such as partition coefficient, adsorption capacity, separation selectivity and recovery efficiency, and their influencing factors. Moreover, this review also puts forward a few available and feasible ideas for the future separation of HMF. In brief, the key objective of this review is to raise more concerns about HMF separation and provide the useful theoretical references and technical supports for the more selective and economical separation of HMF.