Application of vermiculite and limestone to desulphurization and to the removal of dust during briquette combustion

2003 ◽  
Vol 67 (6) ◽  
pp. 1243-1251 ◽  
Author(s):  
A. Lu ◽  
D. Zhao ◽  
J. Li ◽  
C. Wang ◽  
S. Qin
Keyword(s):  
Electron Microscopy ◽  
Coal Combustion ◽  
Combustion Temperature ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Retention Ratio ◽  
X Ray ◽  
Major Factors ◽  
Chemical Reactant ◽  
Scanning Electron

AbstractSmall domestic cooking furnaces are widely used in China. These cooking furnaces release SO2 gas and dust into the atmosphere and cause serious air pollution. Experiments were conducted to investigate the effects of vermiculite, limestone or CaCO3, and combustion temperature and time on desulphurization and dust removal during briquette combustion in small domestic cooking furnaces. Additives used in the coal are vermiculite, CaCO3 and bentonite. Vermiculite is used for its expansion property to improve the contact between CaCO3 and SO2 and to convey O2 into the interior of briquette; CaCO3 is used as a chemical reactant to react with SO2 to form CaSO4; and bentonite is used to develop briquette strength. Expansion of vermiculite develops loose interior structures, such as pores or cracks, inside the briquette, and thus brings enough oxygen for combustion and sulphation reaction. Effective combustion of the original carbon reduces amounts of dust in the fly ash. X-ray diffraction, optical microscopy, and scanning electron microscopy with energy dispersive X-ray analysis show that S exists in the ash only as anhydrite CaSO4, a product of SO2 reacting with CaCO3 and O2. The formation of CaSO4 effectively reduces or eliminates SO2 emission from coal combustion. The major factors controlling S retention are vermiculite, CaCO3 and combustion temperature. The S retention ratio increases with increasing vermiculite amount at 950°C. The S retention ratio also increases with increasing Ca/S molar ratio, and the best Ca/S ratio is 2-3 for most combustion. With 12 g of the original coal, 1 to 2 g of vermiculite, a molar Ca/S ratio of 2.55 by adding CaCO3, and some bentonite, a S retention ratio >65% can be readily achieved. The highest S retention ratio of 97.9% is achieved at 950°C with addition of 2 g of vermiculite, a Ca/S ratio of 2.55 and bentonite.

Diagnosis of Hepatobiliary Disease by Combination of 131I-BSP Blood Retention Ratio with Serial Hepatobiliary Scintigraphy

RADIOISOTOPES ◽  
1974 ◽  
Vol 23 (12) ◽  
pp. 712-716
Author(s):  
Tamio ABURANO ◽  
Kyoichi UENO ◽  
Toshio MAEDA ◽  
Yutaka SUZUKI ◽  
Kinichi HISADA
Keyword(s):  
Hepatobiliary Disease ◽  
Hepatobiliary Scintigraphy ◽  
Retention Ratio

Fluorine-18 fluoromisonidazole tumour to muscle retention ratio for the detection of hypoxia in nasopharyngeal carcinoma

1996 ◽  
Vol 23 (10) ◽  
pp. 1378-1383 ◽  
Author(s):  
Shin-Hwa Yeh ◽  
Ren-Shyan Liu ◽  
Liang-Chih Wu ◽  
David J. Yang ◽  
Sang-Hue Yen ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Retention Ratio

Effect of glucose on lipolysis and on release of lipolytic products in isolated adipocytes

1975 ◽  
Vol 228 (1) ◽  
pp. 92-97 ◽  
Author(s):  
C Naito ◽  
K Okada
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Free Glycerol ◽  
Adipose Tissues ◽  
Simple Diffusion ◽  
Retention Ratio ◽  
Total Mixture ◽  
Isolated Adipocytes ◽  
Effect Of Glucose ◽  
Measured Addition

Isolated adipocytes were prepared from epididymal adipose tissues removed from rats which had been fed or starved for 48 h (fed adipocytes or fasted adipocytes). These cells were incubated at 37 degrees C for 90 min in media containing 0, 3, or 30 mM glucose, with or without norepinephrine (1.0 mug/ml). Then the concentrations of free fatty acids (FFA) and free glycerol (FG) in the total mixture (medium plus cells) and in the medium alone were measured. Addition of glucose to the medium increased the total PG, presumably by increasing the basal lipolysis, and it decreased the intracellular retention ratio of FG (the ratio of intracellular FG to total FG). Addition of glucose did not change the total FFA, but decreased the FFA/FG ratio, presumably by increasing reesterification. The increase in FG and decrease in the FFA/FG ratio on addition of glucose were greater in fed than in fasted adipocytes. The intracellular retention ratio of FFA also decreased on addition of glucose. Glucose enhanced norepinephrine-induced lipolysis (release of free glycerol), and this effect of glucose was greater in fasted adipocytes. However, the increase in FFA in fasted adipocytes induced by norepinephrine was not altered by addition of glucose. In fed adipocytes norepinephrine decreased the total FFA in the presence of glucose. Reesterification of FFA following norepinephrine was increased by addition of glucose. Norepinephrine decreased the intracellular retention ratios of FG and FFA in the presence of glucose. These results suggest that the passage of the lipolytic products, FFA and FG, through the cell membranes may not occur by simple diffusion, but may require energy.

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