Application of Ionic Liquids in the Utilization of the Agricultural Wastes: Towards the One-Step Pre-Treatment and Cellulose Hydrolysis

Cheap, renewable lignocellulosic materials are relevant to the future of biofuel production. Wood and agricultural wastes (e.g. straw, corn stover) provide a raw material source that cannot be used for human consumption, thus biofuels from such sources do not threaten the food supply. The aim of the work was to carry out the pre-treatment and hydrolysis of lignocellulosic material in the same ionic liquid solvent (1-n-butyl-3- methyl-imidazolium-chloride, [Bmim]Cl), using ground wheat straw and a mixture of corn (Zea mays) leaf and stover, as substrates. Our measurements show that it is possible to achieve an acceptable glucose content from the cellulose by applying Cellic® CTec2 and Cellic® HTec2 enzyme complexes

Equilibrium studies of the adsorption of fructo-oligosaccharides from a pure mixture and a fermentative broth on a Dowex Monosphere calcium resin

Fructo-oligosaccharides (FOS) namely, kestose, nystose and fructofuranosylnystose, are prebiotics that can be obtained by fermentation. The resulting fermentative broth is a complex mixture consisting also of salts and other sugars that must be removed. Adsorption equilibrium studies were conducted using the static method in batch mode onto Dowex Monosphere calcium resin, at 60ºC, for FOS contained in a fermentative broth and pure mixtures. Experimental isotherms data were analyzed using linear, Langmuir/anti-Langmuir, Freundlich, Redlich & Peterson, and Toth models. Isotherm parameters were determined using linear and nonlinear correlations for the minimization of several error functions. The nonlinear correlations were found to provide the best isotherm parameters for the models. FOS contained in a fermentative broth were well fitted with anti-Langmuir isotherms, while FOS in pure mixtures were better fitted with Toth, Langmuir and Redlich & Peterson isotherms. A detailed error analysis was carried out to investigate the effect of using different error criteria for the determination of the isotherm parameters

Enzyme kinetics approach to assess biocatalyst inhibition and deactivation caused by [bmim][Cl] ionic liquid during cellulose hydrolysis

The aim of this work was to study the inhibition and deactivation of commercial enzyme cocktail (Cellic® Htec2) in the presence of [bmim][Cl] ionic liquid employing model cellulosic substrate, carboxymethyl cellulose (CMC). It turned out from the experiements – relying on enzyme kinetics appproach – that [bmim][Cl] could act as a competitive inhibitor. Furthermore, depending on the process conditions i.e. contact of enzyme solution with high concentration [bmim][Cl], severe biocatalyst inactivation should be also taken into account as a potential risk during the enzymatic cellulose hydrolysis even in as short process times as few minutes

Controlling TcT_c of Iridium films using interfacial proximity effects

High precision calorimetry using superconducting transition edge sensors requires the use of superconducting films with a suitable $T_c$, depending on the application. To advance high-precision macrocalorimetry, we require low-$T_c$ films that are easy to fabricate. A simple and effective way to suppress $T_c$ of superconducting Iridium through the proximity effect is demonstrated by using Ir/Pt bilayers as well as Au/Ir/Au trilayers. While Ir/Au films fabricated by applying heat to the substrate during Ir deposition have been used in the past for superconducting sensors, we present results of $T_c$ suppression on Iridium by deposition at room temperature in Au/Ir/Au trilayers and Ir/Pt bilayers in the range of $\sim$20-100~mK. Measurements of the relative impedance between the Ir/Pt bilayers and Au/Ir/Au trilayers fabricated show factor of $\sim$10 higher values in the Ir/Pt case. These new films could play a key role in the development of scalable superconducting transition edge sensors that require low-$T_c$ films to minimize heat capacity and maximize energy resolution, while keeping high-yield fabrication methods.Comment: 5 journal pages, 4 figure