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Volume 67, Issue 2
Displaying 1-8 of 8 articles from this issue
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[in Japanese]1988 Volume 67 Issue 2 Pages 75
Published: February 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (216K) -
Toshio SENSHU1988 Volume 67 Issue 2 Pages 76-84
Published: February 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSAtmospheric pollution seems to be affecting extensive areas on the global scale. Burning of fossil fuels increases the density of carbon dioxide in the air, while fron gas released with use of refrigerants or aerosol products may destruct the ozone layer in the stratosphere. Linked with the changes in the global climate, these “background” pollution have assumed increasing importance. Now, Europeans and Americans are concerned about acid rain phenomena affecting forests and lakes over wide areas. Currently, researchers in various countries are making dedicated efforts to elucidate the complex nature and mechanisms of acid rain. This paper illustrates to present status and issues regarding these pollution problems.View full abstractDownload PDF (1183K) -
Takuzo NAGANO1988 Volume 67 Issue 2 Pages 85-96
Published: February 20, 1988
Released on J-STAGE: October 21, 2011
JOURNAL FREE ACCESSIt is the most desirable to recover the valuables from coal ash and to utilize all the coal ash with the treated residue, regarding coal ash produced in large quantity in the future as ground mineral materials already delivered in factory.
For the above purpose, I reviewed the various metal (Al, Fe, Ti) recovery processes from coal ash, and compared their features on the basis of the literature. And I discribed briefly present technical status in Japan.
As the process which seems to be economical, I can list up Direct Acid Leaching process, Hichlor process, Fluorination process, and Calcinter process. Considering technical maturity degree, pollution problem, and site condition for delivery of lime, EPRI's DAL process is thought to be the most easy to commercialize.
I introduced briefly DAL process on the basis of the report of the study results, and explained the remarkable feature.View full abstractDownload PDF (1221K) -
Effects of Operating Temperature and Bed Height on Tar CaptureTomohiko MIYAMOTO, Jinichi TOMURO, Hiroshi MIYADERA, Mizuho HIRATO1988 Volume 67 Issue 2 Pages 97-105
Published: February 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSTar coking might lead a serious trouble in the coal gasification plant, especially when the gasification temperatures are relatively low. Fluidized-ed heat exchanger has a good potential not only to prevent such a coking trouble but to recover heat from a hot gas leaving the gasifier. In this parer, effects of bed temperature and bed height on tar capture were investigated using an apparatus with 0.208m in diameter and 1.4m in height. The amount of accumulated coke on solid in fluidized-bed heat exchanger did not very significantly at temperatures ranging 392 to 554 t . However, at a temperature as low as 427 t, condensed tar did not decompose rapidly and a small amount of liquid tar was expected to appear on the fluidized solids, resulting agglomeration and unstable operation of the fluidized-bed heat exchanger.
At temperatures of 447°C or higher, fluidzed-bed heat exchanger could be operated steadily without agglomeration of the solids. The bed height of the fluidized-bed heat exchanger affected strongly the amount of tar removed through the bed.View full abstractDownload PDF (928K) -
Toshimitsu SUZUKI, Seiji NAKAJIMA, Akihiro YAMAUCHI, Masaru MISHIMA, K ...1988 Volume 67 Issue 2 Pages 106-112
Published: February 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSCatalytic steam and CO2 gasification of Yallourn coal using ferric nitrate-alkali metal carbonate binary catalyst was carried out in a thermobalance at 700-800°C to investigate the binary effect of iron and alkali metal.
The equimolar ferric nitrate-sodium carbonate binary catalyst showed synergistic catalytic effect for the steam gasification of the coal, while the binary catalyst showed additivity for the CO2 gasification. However, the binary catalyst exhibited poorer catalytic activity than the iron-sodium binary catalyst used in the form of sodium hydridotetracarbonylferrate for the steam gasification.
Alkali metal (Na, K, Li) carbonates combined with ferric nitrate more highly promoted the steam gasification than the same amount of alkali metal carbonates. However, binary effects of ferric nitrate-alkali metal carbonates were not remarkable for the CO2 gasification.
Activation of iron by alkali metal can tentatively be interpreted as follows: Iron which tends to be oxidized to higher oxidation state may be reduced by carbon in the char with the assist of alkali metal.View full abstractDownload PDF (731K) -
Jiro SUZUKI, Masato HOSAKA, Yukiyoshi ONO, Yoshitaka KAWASAKI, Atsushi ...1988 Volume 67 Issue 2 Pages 113-122
Published: February 20, 1988
Released on J-STAGE: February 23, 2011
JOURNAL FREE ACCESSRecently, the concerns for improved indoor air quality have been increas-ing. For domestic combustors, the emissions of concern are CO, HC, and NOx
.Reduction of these gaseous pollutants is feasible by replacing the conventional flame-type combustor with a new combustor design. The catalytic combustor is a particularly attractive technique for simultaneous reduction of CO, HC, and NOx, emissions.To develop a domestic catalytic combustor, platinum group metals supported on a ceramic honeycomb were prepared as a catalyst, and their performances for kerosine combustion were investigated.
The main results obtained are as follows.
1) The carrier using 33μm diameter of fused silica has a higher thermal shock resistance than that of using 33μm diameter
2) The optimum amount of platinum group metals on the carrier was between 1-1.5kg/m3.
3) The optimum cell density of the carrier was between 300-400 (1/in2), and optimum depth of the carrier was between 10-20mm.
4) The preferable range of excess air ratio was between 1. 3-1.5.
5) Concentration of NOx in exhaust gas from the test catalytic combustor was about 0.2ppm when the temperature of the catalyst was 800-900°C.View full abstractDownload PDF (1045K) -
Shiro MATSUMOTO1988 Volume 67 Issue 2 Pages 123-129
Published: February 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSCatalysis of iron for steam gasification of Yallourn char in hydrogen atmosphere was studied for the purpose of producing methane. Iron exhibited catalytic activity for steam gasification at its very low concentration, though initial low reactivity was observed for about 200 minutes. The main reaction product was carbon monoxide in spite of hydrogen rich atmosphere.
The mixing of a supported nickel catalyst with iron loaded char remarkably increased gasification rate as well as methane selectivity. The rate of reaction of iron loaded char with the nickel catalyst at 700°C was almost the same or higher than the rate at 800°C without nickel catalyst. It was supposed that the chemisorbed hydrogen atoms on nickel catalyst enhanced the catalytic activity of iron.View full abstractDownload PDF (776K) -
[in Japanese]1988 Volume 67 Issue 2 Pages 130-136
Published: February 20, 1988
Released on J-STAGE: June 28, 2010
JOURNAL FREE ACCESSDownload PDF (1137K)
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