| With the depletion of global fossil resource,the conversion of biomass resources into high value-added platform compounds,such as 5-hydroxymethylfurfural?5-HMF?,has become an important research area for promoting biomass utilization technology.However,separation and purification of 5-HMF from biomass hydrolysate is a major challenges for its large scale industrial production.Resin adsorption separation technology is considered as one of the most advanced technologies,and the key is the selection and preparation of adsorption material.In this work,a series of amide-modified hyper-cross-linked resins were synthesized by suspension polymerization,post-cross-linked,and amination reactions using different monomer/cross-linker ratios.Different mass percentage of toluene were also included a porogen.The effect of pore structure on the adsorption performance of 5-HMF onto resins using both single-and ternary-component systems was investigated.The results showed that the hyper-cross-linked resin with ethylene glycol dimethacrylate/divinylbenzene?1:4 w/w?with 100%?w/w?toluene?PCL-PDE-A-07?had the largest BET surface area?1075 m2/g?and5-HMF capacity?65.8±1.3 mg/g wet resin?.Therefore,the adsorption performance of this resin for 5-HMF in single-component and multi-component systems was studied in detail.In single-component system,the 5-HMF capacity onto PCL-PDE-A-07 resin decreased with increasing temperature,and the maximum adsorption capacity of 5-HMF was 81.3 mg/g wet resin at 298 K.The kinetic adsorption showed that 5-HMF adsorbed onto PCL-PDE-A-07 resin reached equilibrium state about 20.0 minutes.The pore diffusion model?PDM?was used to predict the adsorption kinetics of 5-HMF under different operating conditions.The results showed that the PDM model could better simulate the adsorption-diffusion behavior of 5-HMF onto PCL-PDE-A-07 resin.The effective pore diffusion coefficients were 6.077×10-10,8.098×10-9,1.002×10-9,and 1.237×10-9 m2/s at288,298,308,and 318 K,respectively.In addition,the effects of feed flow rate?Qf=0.6,1.5,3.0,and 6.0 m L/min?and initial concentration?c0=0.56,1.03,2.05,and 4.93 g/L?on adsorption breakthrough curve of 5-HMF were investigated.In multi-component system,the competitive adsorption isotherms and breakthrough curves of fixed-bed column adsorption in 5-HMF-levulinic acid?LA?,5-HMF-formic acid?FA?,LA-FA and 5-HMF-LA-FA systems were studied.It could be concluded that PCL-PDE-A-07 resin showed the maximum capacity for 5-HMF,followed by LA,then FA,and the affinity follows the order:5-HMF>LA>FA.The transient breakthrough curve of weaker adsorbed component in system appeared notable roll-up phenomenon due to the existence of competitive adsorption behavior.Non-competitive and competitive general rate model?GRM?are used to predict the breakthrough curves in different systems,and the validated chromatographic model was used to optimize the design of adsorption separation process,saving manpower and material resources. |
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