Kyushu University · Engineering
Professor Jun-ichiro Hayashi's research lab specializes in advanced membrane science and materials engineering, with a primary focus on the development of carbon molecular sieving (CMS) membranes for gas separation. The lab investigates polyimide-derived carbon membranes through controlled carbonization and post-treatment processes to achieve high permeance and permselectivity for critical industrial separations such as ethylene/ethane and propylene/propane. Key research directions include optimizing membrane fabrication on porous ceramic supports, enhancing oxidative stability, and understanding the thermal behavior of organic polymers during pyrolysis for tailored membrane performance. The lab also explores fundamental aspects of chemical transformation during thermal treatment, linking molecular-level changes to macroscopic transport properties in membranes.
Figures are computed from collected data and may differ slightly.
A BPDA−pp‘ODA polyimide film was formed on the outer surface of a porous alumina support tube (outside diameter, 2.4 mm; inside diameter, 1.8 mm; void fraction, 0.48; and average pore size, 140 nm) and was then carbonized at an optimized temperature of 700 °C. Membranes prepared by repeating this process two and three times respectively exhibited permeances of approximately 1 × 10-8 mol·m-2·s-1·Pa-1 for C2H4 and 2 × 10-9 mol·m-2·s-1·Pa-1 for C2H6 at 100 °C. Permeances to C3H6 and C3H8 at 100 °C
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSimultaneous Improvement of Permeance and Permselectivity of 3,3',4,4'-Biphenyltetracarboxylic Dianhydride-4,4'-Oxydianiline Polyimide Membrane by CarbonizationJun-ichiro Hayashi, Masatake Yamamoto, Katsuki Kusakabe, and Shigeharu MorookaCite this: Ind. Eng. Chem. Res. 1995, 34, 12, 4364–4370Publication Date (Print):December 1, 1995Publication History Published online1 May 2002Published inissue 1 December 1995https://doi.org/10.1021/ie00039a028RIGHTS &
A BPDA-pp‘ODA polyimide film was formed on the outer surface of a porous alumina support tube and was then carbonized in an inert atmosphere at 600−900 °C. The resulting carbon molecular sieving (CMS) membranes were oxidized in O2−N2 mixtures at 300 °C or in CO2 at 800−900 °C, and the permeation properties were determined. The O2 oxidation increased both permeances and permselectivities. The CMS membranes were exposed to air at 100 °C for 1 month, and their resistance to oxidation was determined
This study was carried out for the purpose of experimentally establishing the variation with heating rate of the extent of bridge breaking relative to that of cross-linking, which is a reasonable explanation of the heating rate effect on the tar yield in pyrolysis of low rank coals. A brown coal was pyrolyzed slowly at a heating rate of 0.167 K s-1 and rapidly at 2−3 × 103 K s-1. The yield of tar in the rapid pyrolysis increased with temperature and leveled off at 923 K and 26 mol-C per 100 mol-
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