Catalytic hydrolysis and dehydration of saccharides

In one aspect, methods of HMF production are described herein. A method of HMF production, in some embodiments, comprises providing a saccharide feedstock including glucose and bringing the saccharide feedstock into contact with a solid state catalytic structure at a temperature sufficient to effectuate dehydration of the glucose to provide HMF. The solid state catalytic structure comprises a substrate having one or more surfaces functionalized with saccharide solubilization functionalities and acid functionalities, wherein the saccharide solubilization functionalities comprise one or more imidazolium salts pendant along chains of a first polymeric species attached to the substrate surface

Catalytic membranes and applications thereof

In one aspect, catalytic membranes are described herein. In some embodiments, a catalytic membrane comprises a surface functionalized with a polymer, the polymer comprising cellulose solubilization functionalities and acid functionalities for the catalytic hydrolysis of cellulose and/or hemicellulose

Catalytic membranes and applications thereof

Describe catalytic membranes. In some embodiments, a catalytic membrane comprises a surface functionalized with a polymer, the polymer comprising cellulose solubilization functionalities and acid functionalities for the catalytic hydrolysis of cellulose and/or hemicellulose

Surface engineering for developing new membrane adsorbers

Significant increases in product titers during cell culture means that development of purification processes that can efficiently recover and purify high titer feed streams is a major challenge in the biopharmaceutical industry. On the other hand, introduction of new unit operations is complicated by the significant cost involved in meeting the regulatory requirements for validation and approval of a new unit operation. Recently the development of bio-similars or clones of products for which patent protection has expired, has provided an added competitive incentive for the development of low cost, high efficiency purification processes. Membrane adsorbers are routinely used in the downstream processing of biopharmaceuticals in flow through mode to remove contaminants e.g. host cell proteins, DNA and virus particles. Membrane adsorbers overcome the limitations of resin-based chromatography. Convective flow through the membrane pores overcomes the problems associated with slow internal pore diffusion that plagues resin particles. In addition, scale up of membrane devices is simpler than packed beds. Nevertheless use of membrane adsorbers in bind and elute mode remains limited. This presentation focuses on the importance of engineering membrane surface ligands in order to maximize capacity and recovery in bind and elute operation. Two examples are presented. Bisphosphonate derived ligands have been grafted from the surface of regenerated cellulose membranes. The capacity and flexibility of the ligands are enhanced by copolymerization of N(2-hydroxypropyl) methacrylamide (HPMA). These ligands selectively bind arginine rich proteins. Binding studies indicate the importance of tailoring the three dimensional structure of the ligands in order to maximize capacity and recovery. The mechanism for poly(bisphosphonate-co-polyHMPA) binding has been determined by molecular dynamic simulations. The results obtained highlight the importance of the phosphonate groups as well as HPMA for strong binding interactions and high recoveries. The second example uses responsive ligands that change their conformation in response to changes in external conditions. Membrane based hydrophobic interaction chromatography (HIC) has been conducted using poly(N-vinylcaprolactam) (PVCL) and its copolymers grafted from the surface of regenerated cellulose membranes. PVCL displays a lower critical solution temperature (LCST). The LCST depends on salt type and concentration. At high salt concentration e.g. 1.8 M (NH4)2SO4, used during loading in HIC, the ligand is above its LCST. Consequently it adopts a dehydrated conformation enhancing protein binding. At low ionic strength, during elution, the ligand is below its LCST. It adopts a hydrated conformation leading to protein desorption

Nanofiltration membranes modified by interfacial polymerization and polyelectrolyte deposition for ionic liquid recycling from biomass hydrolysates

Modification of porous polysulfone ultrafiltration membranes was performed by deposition of selective layers via either static polyelectrolyte multilayer deposition technique or growing interfacially polymerized skin layers architectured with 3-aminophenylboronic acid. Model feeds using solutions of 20 mM cellobiose, glucose, xylose and fructose and 115 mM of either of two ionic liquids that are commonly employed in biomass hydrolysis, were prepared to test membrane performance. The fabricated composite membranes show increased ionic liquid/sugar selectivity at competitive permeabilities with tweakable molecular weight cut-offs in the nanofiltration range. Both modification techniques were optimized for nearly complete cellobiose rejection (\u3e99%) and with pure water pearmeabilities corresponding to the range 1.0 – 5.0 L/(m2·h·bar). Overall, polyelectrolyte multilayer membranes showed better permeability at similar rejection performance when compared with interfacial polymerization membranes. Surface characterization with FTIR confirmed boronic acid incorporation for membranes modified via interfacial polymerization and zeta potential analysis coupled with contact angle measurement showed considerable change in surface charge and hydrophobicity with the multilayer polyelectrolyte membranes

Virus reduction filtration in continuous bioprocessing: Critical flux concept for virus breakthrough

Virus reduction filtration is an integral component of virus clearance strategy in modern biologics production processes. Continuous bioprocessing and process intensification are the buzz words in biopharmaceutical industry due to benefits of cost savings from higher productivity, operational flexibility and better product quality. A typical batch process operates virus reduction filters at constant pressure to maximize the throughput within one shift of process time constraint. However, continuous bioprocessing would demand constant low flux virus reduction operation over extended duration to address the complications of frequent filter switching. Due to relaxation of process time constraint, continuous bioprocessing allows better utilization of filter capacity (L/m2). However, there is limited understanding around the virus breakthrough mechanism and associated critical process parameters. This poses an interesting question how to define end point for virus reduction filtration while utilizing most of the filter capacity for low fouling feed. What is the effect of flux, differential pressure and total viral particle load on virus clearance performance of commercially available viral filters? Is there a critical flux for viral reduction filters below which they are susceptible to significant virus breakthrough (LRV \u3c4) and if yes, how sensitive it is to filter’s property and other process parameters? This study explores the effect of flux, differential pressure and total viral particle load on viral clearance performance of three commercially available filters. These filters are selected to cover the wide range of filter permeability and membrane material. The viral clearance study was performed both in the presence and absence of products

Effects of free heave motion on wave resonance inside a narrow gap between two boxes under wave actions

Fluid resonance inside a narrow gap between two side-by-side boxes is investigated based on an open-source CFD package, OpenFOAM. An upstream box heaves freely under wave actions and a downstream box remains fixed. The focus of this work is to study the influence of the motion of the upstream box on the hydrodynamic behavior of the resonant fluid inside the gap. The hydrodynamic behavior considered in this study includes the wave height inside the gap, heave displacement and their harmonic components, and reflection, transmission and energy loss coefficients. For comparison, the configuration in which the two boxes are fixed is considered. It was found that the heave motion of the upstream box increases the fluid resonant frequency and significantly reduces the resonant wave height in the gap. The frequencies at which the maximum and minimum heave displacements of the upstream box are observed to obviously deviate from the fluid resonant frequency. For the wave height in the gap and heave displacement, the effects of the incident wave height on their harmonic components are different. The heave motion of the upstream box results in a larger reflection coefficient and smaller energy loss coefficient

Magnetically responsive membranes

The invention provides permeable magnetically responsive filtration membranes that include a filtration membrane polymer base suitable for fluid filtration; hydrophilic polymers conjugated to the surface of the filtration membrane polymer; and magnetic nanoparticles affixed to the ends of a plurality of the hydrophilic polymers, wherein the hydrophilic polymers are movable with respect to the surface of the filtration membrane polymer surface in the presence of an oscillating magnetic field