返回Google圖書搜尋

Chemisorption, Reaction and Desorption Studies of Coal Chars in Steam, Oxygen and Carbon Dioxide

其他書名	Final Report (January 1986-December 1989)
出版	Gas Research Institute, 1990
URL	http://books.google.com.hk/books?id=u9AlGwAACAAJ&hl=&source=gbs_api

註釋The use of a transient kinetics (TK) technique allowed a direct measurement of reactive surface area (RSA) for chars gasified in both CO2 and O2, i.e., gasification rates normalized with respect to RSA were essentially constant over the entire conversion range. A temperature-programmed desorption (TPD) technique was also used to determine the amount of reactive surface intermediate formed on these chars during gasification in CO2 and O2; the results were in good agreement with those obtained by TK. In addition, TPD allowed an important distriction to be made between the stable C-O complexes and reactive C(O) intermediates residing on the char surface during gasification in CO2 and O2. The application of these two independent but complementary techniques provided a satisfactory quantitative understanding of char reactivity variations with conversion in CO2 and O2. Both techniques possess the unique capability of separately determining the reaction rate constant (site reactivity or turnover frequency) and the number of active sites participating in the reaction (RSA). A comparison of turnover frequencies for different chars gasified in 1 atm CO2 suggested that char gasification may be a structure sensitive reaction. The concept of reactive surface area was also used to achieve a better quantitative understanding of catalyzed char reactivity variations with conversion in carbon dioxide.