Yuichi Shimizu

Nickel-catalyzed carbonization of wood for coproduction of functional carbon and fluid fuels I: production of crystallized mesoporous carbon

Japanese larch wood loaded with nickel (1%–4%) alone or with nickel and calcium (0.25%–1.5%) was carbonized at 800°–900°C for 0–120min with a heating rate of 5°–20°C min−1 in a helium flow of 5.8−46.4 ml STP cm−2 min−1 to examine the influence of these variables on the crystallization of carbon (the formation of T component) and the development of mesoporosity. From the obtained results, reaction conditions suitable for effective production of carbon with the dual functions of adequate electroconductivity and adsorption capacity in liquid phase were established, thereby explaining the factors that govern the process. It was also confirmed that mesopore having a diameter of about 4 nm was selectively produced at the cost of specific (BET) surface area in parallel with the formation of T component. This result provided good insight into how the simultaneous dual function could be realized.

Irradiation effects of excimer laser radiation and electron beam on polypropylene and ethylene-tetrafluoroethylene copolymer films

Abstract The irradiation effects of the intense ultraviolet radiation from an excimer laser on polypropylene (PP) and ethylene-tetrafluoroethylene (ETFE) copolymer films are compared with those from electron beam studies. Irradiation of PP films with a KrF laser and an electron beam induced the degradation of the polymer, and use of an ArF laser selectively decomposed the alkyl phenol type additive contained as an antioxidant in PP instead of degrading the polymer. Irradiation with a KrF laser induced the carbonization of ETFE copolymer due to polymer degradation, and irradiation with an ArF laser and an electron beam formed CO and CC groups in the polymer chains.

Nickel-catalyzed carbonization of wood for coproduction of functional carbon and fluid fuels II: improved fuel quality of oil fraction and increased heating value of gas fraction

The yields and properties of oil and gas fractions coproduced during carbonization of larch wood loaded with Ni 2%, Ni 2%+Ca 1%, and Ni 4% and without catalyst (None) at 700°–900°C were examined to clarify the catalytic effect in terms of conversion into fluid fuels. The net calorific value of oil occurred mainly below 500°C and increased in the order None < Ni 2% < Ni 4% < Ni 2%+Ca 1%, while the yield decreased in this order. The same order held for the production of gases enriched with hydrogen at 500°–700°C. Even above 800°C, markedly promoted evolution of hydrogen took place for all catalyst systems. These observations confirmed the effectiveness of nickel-catalyzed carbonization at 900°C, particularly Ni 2%+Ca 1%, for both upgrading of oil and gaseous fractions, although the quality of oil was not satisfactory. The catalysis of nickel with and without calcium is discussed on the basis of the modified Broid-Shafizadeh scheme, and the scheme was altered to adapt to the high temperature region where oil was no longer produced.

Enantioenrichments of α -Amino Acids With High-Intensity Excimer Laser

It has been found that the irradiation with highly intense circularly polarized light (CPL) from an XeF (351 nm) laser can induce the enantiodifferentiation of racemic methionine with reasonable enantiocontrol by switching the sense of the CPL. Also, a similar result was obtained for threonine and it was newly revealed that the enantioenrichment is largely affected by the chemical structure, especially the functional groups, of α-amino acids, to cause photodecomposition such as decarboxylation and deamination. Furthermore, it was shown for the first time that the irradiation of a proline (Pro)-valine (Val) mixture with the CPL induces their enantioselective decomposition simultaneously, suggesting the occurrence of intermolecular interaction between Pro and Val.

LASER-INDUCED PHOTOCHEMICAL REACTION OF MALEIC ACID SOLUTIONS IN THE PRESENCE OF HYDROGEN PEROXIDE

Targeting the selective and direct synthesis of tartaric acid (TA), the photochemical reactions of maleic acid (MA) solutions containing H2O2. in various solvents have been investigated using four wavelengths in the UV region between 193 and 351 nm, with high intensity from an excimer laser. All the laser irradiations in H2O resulted in the direct synthesis of TA with lower selectivity and it was found that, with XeF-laser (351 nm) irradiation in 1,4-dioxane, TA is selectively and directly synthesized from MA containing H2O2 of lower concentration at room temperature. On the other hand, none of the irradiations in methanol, N,N-dimethylformamide, acetonitrile, and tetrahydrofuran gave the selective formation of TA. On the basis of these results, the reaction scheme for the selective formation of TA is discussed.

Laser-induced enantiodifferentiating reaction of tartaric acid using high-intensity circularly polarized light

High-intensity right circularly polarized light (CPL) from an XeF (351 nm) laser induces selective enrichment of D-tartaric acid (D-TA) while the left CPL induces enrichment of the L-tartaric acid (L-TA), revealing a clear correlation between enantioselection and the sense of the CPL.

An efficient enantiomeric enrichment of tartaric acid using a highly intense circularly polarized light

An efficient method is described for the enantiomeric enrichment of tartaric acid by irradiation with a focused circularly polarized light from an excimer laser.