Yoshinori Iiguni

Single shot pyrolysis and on-line conversion of lignocellulosic biomass with HZSM-5 catalyst using tandem micro-reactor-GC-MS

It was demonstrated that a tandem micro-reactor coupled to a gas chromatograph-mass spectrometer (tandem micro-reactor-GC-MS) system can be successfully applied to study single-shot pyrolysis and on-line catalytic conversion (ex situ catalytic pyrolysis) of biomass samples using HZSM-5 catalyst. The pyrolysis of beech wood without using any catalyst produced various oxygenated compounds; prominently carbon dioxide, levoglucosan and acetic acid at all tested pyrolysis temperatures of 400, 500 and 600 °C along with aldehydes, ketones, and phenols. In the ex situ catalytic pyrolysis of the beech wood using HZSM-5, the yields of the oxygenated hydrocarbons were significantly reduced, whereas various aromatic compounds including furan, benzene and its alkylated derivatives, indane, indenes and naphthalenes were formed through catalytic conversion. The relative yields of these products changed depending on the pyrolysis temperature. The catalytic effect was observed even at the lowest catalyst loading of 2.5 mg. An increase in catalyst loading led to an increase in the relative yields of aromatic hydrocarbons. The catalyst de-activation test in the tandem micro-reactor showed that HZSM-5 catalyst can be repeatedly used with little loss of its activity. The tandem micro-reactor-GC-MS with HZSM-5 was also applied to other types of biomass (cellulose and microalgae). It was found that the relative yields of BTX (benzene, toluene, xylene) changed considerably depending on the type of biomass, probably due to the difference in the feedstock composition.

Dynamic electromagnetophoretic force analysis of a single binding interaction between lectin and mannan polysaccharide on yeast cell surface.

Using the electromagnetophoretic buoyancy for a microparticle in a silica capillary containing an electrolyte solution, the dynamic force dissociation kinetics of the interaction between the mannan polysaccharide on a yeast cell surface and lectins bound to the silica capillary wall have been studied by using the two different modes of the increasing force mode and the constant force mode. Lectins used in the study were concanavalin A (Con A), Hippeastrum hybrid lectin (HHL), Galanthus nivalis lectin (GNL) and Narcissus pseudonarcissus lectin (NPL). The dynamic force measurement by the two different modes gave the spontaneous dissociation rate constant, k(off), of the polysaccharide-lectin binding and the critical increment of bond length at the transition state, Deltax. It was found that the value of k(off) for Con A was the smallest among the lectins studied, due to the strongest binding interaction. It was also confirmed that the magnetophoretic pulling force decreased the transition free energy just like an enzyme.

Continuous-flow Size-based Separation of Microparticles by Microchip Electromagnetophoresis

A novel microchip separation method for microparticles based on electromagnetophoresis was developed. In this method, a double Y-shape microchip with two inlets and two outlets was used for particle separation. Microparticles of two different sizes were suspended in an aqueous solution and introduced into the microchannel from one inlet with a stream of the aqueous solution without particles from another inlet by a hydrodynamic flow. Then, the particles with two different sizes were migrated orthogonal to the flow by elctromagnetophoresis and separated to different outlets based on the difference in their electromagnetophoric velocities, which depended on the size of particle. Using this method, at one outlet, 89% of 3 μm polystyrene latex particles were isolated from a mixture of 3 and 10 μm particles. By combining hydrodynamic focusing, both 3 and 10 μm particles were recovered at the different outlets with 100% purity and recovery, respectively. Even the separation of 3 and 6 μm particles was also achieved with about 98% recovery and purity. Moreover, yeast cells and polystyrene particles could be separated with high separation efficiency by this technique.

Characterization of the cross-linking structures in UV- and EB-cured acrylic copolymer resins using high resolution MALDI-spiral-TOFMS combined with supercritical methanolysis

The cross-linking structures of ultraviolet (UV) and electron beam (EB)-cured acrylic copolymer resins prepared with pentaerythritol triacrylate and 1-vinyl-2-pyrrolidone (VP) mixtures were characterized using high resolution matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOFMS) combined with supercritical methanolysis. Methyl acrylate (MA)/VP co-oligomers were formed via methanolysis through selective cleavage and methylation at the ester linkages in the radiation-cured resins, which reflected the cross-linking junctions. Almost all of the products were completely separated in the high-resolution spiral TOFMS spectra, including the isotope peaks for a slight mass difference of Δm/z ≃ 0.05. Two types of the copolymeric methanolysis products with different terminal structures were identified for up to 11-mers at approximately m/z 1300 on the MALDI mass spectra. The distributions of the products observed in the mass spectra were interpreted in terms of the original structures of the cured resin samples to reflect the curing reactions.

Staggered-electromagnetophoresis with a Split-flow System for the Separation of Microparticles by a Hollow Fiber-embedded PDMS Microchip

A novel microchip separation system for microparticles based on electromagnetophoresis (EMP) was developed. In this system, focusing and separation of flowing microparticles in a microchannel could be performed by staggered-EMP by controlling the electric current applied to the channel locally combined with the split-flow system for fractionation of eluates. To apply the electric current through the flushing medium in the microchannel, a hollow fiber-embedded microchip with multiple electrodes was fabricated. The hollow fiber was made by a semi-permeable membrane and could separate small molecules. This microchip allowed us to apply the electric current to a part of the microchannel without any pressure control device because a main channel contacted with the subchannels that had electrodes through the semi-permeable membrane. Moreover, the separation using this microchip was combined with the split-flow system at two outlets to improve separation efficiency. Using this system, with the split-flow ratio of 10:1, 87% of 3 μm polystyrene (PS) latex particles were isolated from a mixture of 3 and 10 μm particles. Even the separation of 6 and 10 μm PS particles was achieved with about 77% recovery and 100% purity. In addition, by controlling the applied current, size fractionation of polypropylene (PP) particles was demonstrated. Moreover, biological particles such as pollens could be separated with high separation efficiency by this technique.