A laboratory-scale fluidized bed gasifier was used to pyrolyze lignite under a wide range of gasification temperatures (873-1123 K). The obtained tar components were clarified using an analytical method combining gas chromatograph mass spectroscopy (GC/MS) and field desorption mass spectrometry (FD-MS). As a result, the main tar components obtained at the maximum temperature of 1123 K were polycyclic aromatic hydrocarbons (PAHs) without substituents and peaks in molecular weight intervals of 24 and 26 were observed. Tar components increased as the gasification temperature decreased, including PAHs without substituents and PAHs with substituents such as methyl groups. These tar components were observed to have peaks in the molecular weight intervals such as 14, 50, 76, in addition to 24 and 26. Furthermore, pyrolysis at a freeboard temperature of 873 K produced a significant number of tar components, some of which were oxygen-containing compounds. These included oxygen-containing PAHs with hydroxyl groups as substituents as well as methyl groups. Regularity with molecular weight intervals such as 14, 16, 50, and 76 was also observed. However, when the freeboard temperature increased to 1123 K, the main components were substantially reduced, such that the unsubstituted PAHs were prominent.

Basic information concerning the factors controlling oxidative desulfurization was investigated using the structures and reactivity of benzothiophene and dibenzothiophene derivatives with data from molecular orbital (MO) calculations and oxidation reactions. Highly condensed aromatic compounds had higher reactivity, agreeing well with the order based on MO calculations. Methyl groups in the 2-position of benzothiophene accelerated the reaction, also agreeing well with the results of MO calculations. On the other hand, methyl groups at the 4- and/or 6-positions of dibenzothiophene had different effects depending on the reaction conditions and the nature of the active species. MO calculation indicates that methyl groups enhance the reactivity of the substrates because of their electron donating nature. However, conversion of the methylated substrates decreased in reactions using bulky oxidants such as aliphatic peracids or peroxides with aryl substituents, suggesting the importance of steric hindrance by the methyl groups.

A series of silica-supported indium oxides (In₂O₃/SiO₂) and Co-modified In₂O₃/SiO₂ (Co/In₂O₃/SiO₂) were prepared by impregnation methods and tested as noble-metal-alternative catalysts for acetylene semihydrogenation. Although In₂O₃/SiO₂ was active for acetylene semihydrogenation, deactivation occurred within a few hours probably due to by-production of poisonous species. When In₂O₃/SiO₂ was further modified with a small amount of Co (0.5 wt%), acetylene conversion and ethylene selectivity retained high levels (approximately 70 %). For the Co/In₂O₃/SiO₂ catalyst, hydrogen pretreatment temperature had strong influence on the catalytic performance, in which reduction by H₂ at 250 °C resulted in the best stability. A temperature-programmed reduction study suggested that metallic Co species contributed to inhibiting the formation of poisonous by-products, which allowed to improve the stability in the catalytic performance.

The two-layered and three-layered hierarchical catalysts with micropore-small mesopore-large mesopore (micro-meso-meso) structures were prepared using the gel skeletal reinforcement (GSR) method. A Curie point pyrolyzer method was used to evaluate their properties in the catalytic cracking of low density polyethylene (LDPE) and the effects of their pore structure and zeolite type were investigated. The two-layered catalyst prepared with malic acid, TEOS and β-zeolite achieved conversion of 78 % and was more active than similar Y-zeolite-based catalysts. The three-layered catalyst, in which the two-layered catalyst was dispersed in silica made by the GSR method, maintained the conversion despite lower zeolite content. Evaluation of conversion against the XRD integrated intensity and the number of acid sites of the zeolite as a measure of the relative activity of the catalyst found that the relative activity was higher for the hierarchical structured catalyst than for single zeolite and kaolin-mixed catalysts.

Natural gas is attracting attention as an alternative fossil resource to oil. As the primary component of natural gas is methane, there is a growing demand for the development of catalytic processes capable of direct CH₄ conversion into valuable chemicals. In this study, the dehydrogenative conversion of CH₄ over Pt/Al₂O₃ catalysts was investigated. C₂ hydrocarbons and aromatics were formed from CH₄ at moderate reaction temperatures (550-600 °C). At low concentrations of CH₄, no hydrocarbons were produced, and coke deposition predominated. From the results, we considered that adsorbed methyl and methylene species were coupled on the Pt surface, forming hydrocarbons. Although the Pt/Al₂O₃ catalyst was deactivated by coke deposition, it was found that the removal of coke by oxygen treatment regenerated the catalytic activity of the Pt/Al₂O₃.

Silica-supported Cu(II) acetate complexes were prepared and characterized via elemental analysis and several spectroscopic techniques. Cu K-edge X-ray absorption fine structure (XAFS) analysis revealed the presence of a Cu(II) complex with a diamine ligand. The catalyst with a co-immobilized tertiary amine showed a higher performance for the Chan–Evans–Lam coupling reaction of aniline with phenylboronic acid to produce diphenylamine compared with the catalyst without a tertiary amine. Characterization and catalytic reaction results indicated that the tertiary amine accelerates transmetallation between the Cu(II) complex and phenylboronic acid, producing Cu–Ph species.

Cu zeolites have been developed as catalysts for partial oxidation of CH₄. Our previous study evaluated the redox behaviors of Cu-CHA and Cu-MOR zeolites, which have relatively high performance for CH₄ partial oxidation among various Cu zeolites, using Cu K-edge X-ray absorption fine structure (XAFS) spectroscopy. In the present study, a Cu-MFI zeolite with high CO₂ selectivity, i.e., a not good catalyst for CH₄ partial oxidation was analyzed using in situ XAFS spectroscopy. Data for Cu-MFI were combined with the previous data for Cu-MOR and Cu-CHA to investigate the relationship between the Cu^2+/+ redox rates and the catalytic characteristics. The reduction rate of Cu²⁺ to Cu⁺ was strongly correlated with the CH₄ oxidation activity because the C–H activation of CH₄ involves the reduction of Cu²⁺. However, the Cu^2+/+ redox rates showed no clear relationship with the selectivity.

In the synthesis of organic carbamate from CO₂ using Si(OMe)₄, which is a regenerable reagent, and a Zn(OAc)₂/1,10-phenanthroline (phen) catalyst, the effect of substituents on the phen ligands was evaluated to further improve the reaction efficiency and to elucidate linker introduction sites for catalyst immobilization. Therefore, the synthesis of methyl phenylcarbamate was investigated using a Zn(OAc)₂ complex with a phen-derivative ligand bearing an electron-donating or electron-withdrawing group, (X-phen)Zn(OAc)₂, as the catalyst, and its catalytic activity was compared to that of (phen)Zn(OAc)₂. Consequently, catalysts with 2,9-substituted and 4,7-halogenated X-phen ligands (X-phen = 2,9-dimethyl-1,10-phenanthroline, 2,9-dibutyl-1,10-phenanthroline, 4,7-dichloro-1,10-phenanthroline, and 4,7-dibromo-1,10-phenanthroline) were demonstrated to be significantly less efficient than (phen)Zn(OAc)₂. For the other (X-phen)Zn(OAc)₂ catalysts (X-phen = 4,7-bis(dimethylamino)-1,10-phenanthroline, 4,7-dimethoxy-1,10-phenanthroline, 4,7-dimethyl-1,10-phenanthroline, 3,4,7,8-tetramethyl-1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline, and 5-nitro-1,10-phenanthroline), the carbamate yield did not change significantly compared to that obtained with (phen)Zn(OAc)₂ regardless of whether the substituent introduced into the phen ligand was an electron-donating or electron-withdrawing group. The above information on the positions of substituents and types of functional groups that do not affect the carbamate synthesis reaction is useful for introducing a linker on the phen ligand to immobilize the catalyst, and will contribute to further improvement of the efficiency of the carbamate synthesis.

Industrial plant operators have so far relied mainly on the wisdom and experience of experts to make effective use of huge amounts of text information such as accident cases and near-miss reports. However, the aging and retirement of experienced skilled workers has made continued effective use into a common issue for industrial plant operators. The present study created prototypes of two analysis methods, analysis based on words (text mining+Bayesian network) and analysis based on technical data (ontology) as possible solutions to this problem. In the future, we plan to systematize the created prototype for use in the cloud, and to build a “safety information platform” equipped with a “safety information database” and “analysis software.” In addition, we will also continue to improve the operation/management method after the system is launched for connection to a system that allows continuous operation.