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BACKGROUND: Recently much research has been focused on the production and refinery of biobased fuels. The production of biofuels derived from lignocellulosic biomass is recognized as a promising route to produce biobased fuels responsibly. Often, product streams (e.g. glucose) still contain small amounts of undesired components (e.g. furans such as HMF). This study focuses on the removal of furans produced during the fermentation. In earlier work, styrene based resins have been identified as promising materials for this separation. In this work the kinetic properties of the most promising resin: Dowex™ Optipore™ L493 are studied. RESULTS: The diffusion coefficient of 5 mg L-1 HMF was ~8 × 10-12 m² s-1 in water and 3.0 × 10-12 m² s-1 in a glucose solution. The reduced diffusion coefficient in the particle when glucose is present is caused by the higher viscosity of the glucose solution and it indicates that diffusion is controlled by surface and pore diffusion. The breakthrough curves of HMF on Optipore showed that the column is very efficient under conditions of interest. CONCLUSION: This study shows that Optipore is a much more efficient resin for HMF removal than currently used resins. Its fast kinetics and capacity make it possible to efficiently remove HMF from glucose solutions. [ABSTRACT FROM AUTHOR]

BACKGROUND Many countries have set goals to replace conventional energy sources with renewable energy sources. This has led to investigations into the use of lignocellulosic biomass as a feedstock for renewable fuels and base chemicals. Unfortunately hydrolysation of this biomass introduces impurities that are toxic to the fermentation bacteria. This study aims to find the key adsorber properties for the separation of toxic 5-hydroxymethylfurfural ( HMF) from glucose. RESULTS Batch adsorption experiments on styrene based (anion exchange) adsorbers showed that a high surface area is a key property for effective HMF adsorption. Introduction of polar groups in the form of anion exchange groups appears to increase the HMF-affinity of the resin material, unfortunately these groups also introduce affinity for glucose. Competitive adsorption studies of HMF and glucose showed that glucose does not affect HMF adsorption in any of the resins. CONCLUSION Furan derivatives can be removed from water and sugar solutions with styrene based (anion exchange) polymeric resins. For efficient removal, a high surface area of the resin is a key property. Dowex Optipore L-493 shows the best specific HMF adsorption and no specificity for glucose, which makes it an excellent adsorber for HMF removal from hydrolysate for the fermentation of glucose. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The permeation properties of a series of block copolymers based on poly(ethylene oxide)-ran-poly(propylene oxide) (PEO-ran-PPO) soft segments and monodisperse tetra-amide (T6T6T) hard segments have been studied. The polyether soft segment used in the current study differs from the commonly used pure poly(ethylene oxide) (PEO) soft segment by the fact that it contains 25 wt % randomly distributed poly(propylene oxide) (PPO). The presence of the methyl group of PPO suppresses crystallization of the soft segment and strongly improves the permeability of these materials, especially at subambient temperatures. In addition, the unique monodisperse character of the hard segment ensures a very well phase-separated morphology, resulting in a very pure soft phase. The soft segment length of these block copolymers was varied between 1000 and 10000 g/mol (62-89 wt %). High soft segment concentrations and flexibility were obtained resulting in high CO(2) permeabilities (up to 570 Barrer at 50 degrees C). Due to the random distribution of PPO in the predominantly PEO based soft segment crystallization of PEO was not observed at temperatures as low as -10 degrees C. CO(2) permeabilities exceeding 200 Barrer could be obtained at this low temperature. The CO(2)/light gas selectivity in these materials is governed by the solubility selectivity and consequently only slightly lowered because of the introduction of PPO in the soft segment. Comparison with literature revealed that this block copolymer system has exceptionally high CO(2) permeabilities combined with reasonable CO(2)/light gas selectivities. It is very interesting in CO(2) separation processes where subambient conditions are present (e.g., separation of CO(2) from natural gas), as at these low temperatures, one can take maximum advantage of the increased separation ability of the polymer materials while maintaining excellent transport characteristics.