Reaction-extraction-reaction coupling process: The key role of intermediate product extraction during 5-chloromethylfurfural (CMF) production in the microreactor

Production of 5-chloromethylfurfural (CMF) from fructose conducted in two-liquid phase system has achieved a considerable CMF yield. However, correlation between extraction process and CMF yield has not been reported yet. Herein, we found quantitative relation between interfacial specific area ( a ), extraction efficiency of 5-hydroxymethylfurfural (HMF) (E HMF ),a significant precursor of CMF and selectivity of CMF (S CMF ) in the microreactor. First, we systematically investigated the impact of flow rate ratio of two phases ( F C /F D ), total fluid velocity ( u ) and residence time on S CMF and E HMF . It turned out that both F C /F D and u had a significant impact on S CMF and E HMF . In addition, both u and F C /F D had a significant impact on interfacial specific area ( a ). As u varied, we fitted and observed a linear relation between u & a (R 2 =0.994), a & E HMF (R 2 =0.997) and E HMF & S CMF (R 2 =0.999). It indicated that CMF selectivity could be controlled by HMF extraction under certain conditions. Based on these results, we proposed a strategy for obtaining high CMF productivity from fructose in the microreactor. 93.9% CMF yield (11 g/L fructose concentration) and 89.9% CMF yield (110 g/L fructose concentration) were obtained. To the best of our knowledge, this work first proposes coordination between reaction and extraction in CMF production.