This paper introduces the effect of dolomite and limestone on waste tyre pyrolysis When waste tyre was pyrolyzed in 700?℃, the derived gases was passed through the catalyst zone in which the temperature was controlle...This paper introduces the effect of dolomite and limestone on waste tyre pyrolysis When waste tyre was pyrolyzed in 700?℃, the derived gases was passed through the catalyst zone in which the temperature was controlled at 700?℃, 800?℃and 900?℃, respectively It is found that both dolomite and limestone affect the product distribution of tyre pyrolysis with erhancing gas yield and effective absorption of H 2S The effect of these catalysts on tar cracking is obvious at 900?℃, however, the life of catalyst is short The product yields are about 40% for gas, 30% for liquid and 30% for char in the presence of dolomite and limestone The result indicates that multi use of the pyrolysed product is highly recommended [WT5H1]展开更多
The long term trend of ozone level in Hong Kong has been investigated. One of the characteristics of ozone level in Hong Kong is the existence of autumn maximum and summer minimum. Observations of the diurnal variatio...The long term trend of ozone level in Hong Kong has been investigated. One of the characteristics of ozone level in Hong Kong is the existence of autumn maximum and summer minimum. Observations of the diurnal variation of ozone level have been made in different area categories. There are early morning peak and afternoon peak occurred in the diurnal variation, which are different from some metropolitans where only an afternoon peak is observed. A negative correlation coefficient was found between monthly ozone level with nitric oxide level. On the contrary, there is a positive correlation between ozone and nitrogen dioxide. The positive correlation coefficient between nitric oxide and nitrogen dioxide shows that the total amount of nitric oxide emitted from a series of moving and fixed sources greatly exceeded the stoichiometric amount of ozone formed from chemical reactions of precursors and long distance transportation.展开更多
文摘This paper introduces the effect of dolomite and limestone on waste tyre pyrolysis When waste tyre was pyrolyzed in 700?℃, the derived gases was passed through the catalyst zone in which the temperature was controlled at 700?℃, 800?℃and 900?℃, respectively It is found that both dolomite and limestone affect the product distribution of tyre pyrolysis with erhancing gas yield and effective absorption of H 2S The effect of these catalysts on tar cracking is obvious at 900?℃, however, the life of catalyst is short The product yields are about 40% for gas, 30% for liquid and 30% for char in the presence of dolomite and limestone The result indicates that multi use of the pyrolysed product is highly recommended [WT5H1]
文摘The long term trend of ozone level in Hong Kong has been investigated. One of the characteristics of ozone level in Hong Kong is the existence of autumn maximum and summer minimum. Observations of the diurnal variation of ozone level have been made in different area categories. There are early morning peak and afternoon peak occurred in the diurnal variation, which are different from some metropolitans where only an afternoon peak is observed. A negative correlation coefficient was found between monthly ozone level with nitric oxide level. On the contrary, there is a positive correlation between ozone and nitrogen dioxide. The positive correlation coefficient between nitric oxide and nitrogen dioxide shows that the total amount of nitric oxide emitted from a series of moving and fixed sources greatly exceeded the stoichiometric amount of ozone formed from chemical reactions of precursors and long distance transportation.
