Naohiro Nojiri

Recent progress in catalytic technology in japan

Abstract The development of catalytic technology in Japan in the past several years has been reviewed. Four representative catalysts, i.e., palladium-tellurium bimetal, heteropoly acid, chiral rhodium complex, and microorganism, that are used in newly industrialized catalytic processes, are described in some detail based on published documents.

Recent progress in catalytic technology in Japan— a supplement

Abstract This review was prepared as a supplement to our previous one [M. Misono and N. Nojiri, Appl. Catal., 64 (1990) 1] adding approximately 60 new examples to cover extensively the catalytic processes and catalysts commercialized in Japan during the decade of the 80s. The examples are classified into three tables (New catalytic processes, New catalysts, and Emission control catalysts) with references.

Two Catalytic Technologies of Much Influence on Progress in Chemical Process Development in Japan

Abstract A tremendous number of new catalytic chemical processes have been established and commercialized in Japan in recent years [l, 21. Table 1 shows typical Japanese-made technologies and processes from 1957, about which time the petrochemical industry started in Japan. In those days almost all processes adopted were either fully licensed from foreign companies in Western Europe and the U.S. or completed in Japan as a practical technology using basic and original ones discovered by the foreign companies. In 18 years, from 1957 to 1974, when the Japanese petrochemical industry matured and rapidly magnified its scale, 22 new technologies and processes were accomplished in Japan; however, some of them are not intrinsically Japanese for the reason already mentioned—they derived from foreign companies—and some others were only the first in Japan but not the first in the world. The next 17 years (1975–1992), which included two oil embargoes and were regarded as the time the industry entered the age of a low...

Epoxidation of ethylene over AgNaCl catalysts

Epoxidation of ethylene over sodium chloride-doped and granular sodium chloride-supported silver catalysts was performed at atmospheric pressure using conventional flow reactors. Although the stationary activity was somewhat low, each type of catalyst has shown high selectivity, 84–87%, under an ethylene-rich atmosphere. The selectivity was almost independent of reaction temperature, contact time, and catalyst composition. The total reaction rate rose exponentially with temperature until an apparent activation energy of 75.3 kJ mol−1 was obtained. Under oxygen-rich atmospheres, marked drops in activity were observed. In exposing the deactivated catalysts to a stream of hydrogen, carbon dioxide was desorbed. The strongly enhanced adsorption of carbon dioxide promoted the formation of silver chloride. Silver particles on the granular sodium chloride were homogeneously dispersed and ~200 nm in size. In addition, the crystallite size of silver was 43–50 nm, which was not altered after the reaction or even after heating at 673 K in oxygen gas. In a pulse reaction using an ethylene-rich gas mixture, acetaldehydes other than ethylene oxide were formed, and, as the catalyst surface had been oxidized by irreversible adsorption of oxygen, the formation of carbon dioxide was promoted and that of acetaldehyde decreased.

A novel silver catalyst prepared by using superheated-steam as a heating medium for ethylene oxide production

A high-performance catalyst for the production of ethylene oxide by vapor phase oxidation of ethylene was developed and commercialized. High performance was achieved by the usage of a high surface area carrier with controlled pore distribution and surface acid-base properties, by the adoption of mixed amines to dissolve heat-decomposable silver salt, by the addition of effective additives, and by the introduction of a uniquely developed heat-treatment technology using superheated-steam as the heating medium. The catalyst thus prepared showed high activities because of homogeneously and highly dispersed silver and additive elements within the carrier. As a result, the reaction temperature could be lowered, which led to the improvement of not only the selectivity but also the catalyst life. Heat treatment with superheated-steam proved to have many advantages in producing high-performance catalysts and it is commercially favorable because it needs only a very short processing time.

Synthesis of a 110 K Superconducting Phase in the Bi-Sr-Ca-Cu-O System

We have prepared a 110 K superconducting phase as the dominant phase in the BiSrCaCu2Ox ceramic by sintering at 865±5°C for 900 h in air. This superconductor has a resistance Tc of 109.3 K and a structure containing stacking faults, as suggested by the broadened X-ray diffraction pattern. The volume fraction of the 110 K phase is as large as 28% by dc susceptibility measurements.