화학공학소재연구정보센터
Journal of Catalysis, Vol.197, No.1, 43-48, 2001
Autothermal oxidative dehydrogenation of ethane to ethylene using SrxLa1.0Nd1.0Oy catalysts as ignitors
The behavior of SrxLa1.0Nd1.0Oy catalysts with different Sr loading (x = 0, 0.001, 0.01, 0.1, and 1.0) was examined regarding their application as ignitors for the autothermal oxidative dehydrogenation of ethane. Ethylene yields as high as 42% (S > 69%) were obtained at a contact time of similar to 45 ms (STP) as a result of the ignition of the reaction mixture on the catalyst and the resultant occurrence of the thermal ethane pyrolysis. The catalysts showed comparable performance; a slightly higher ethylene yield (45%) was obtained on a Sr0.1La1.0Nd1.0Ox catalyst on which the optimization of the reaction conditions was carried out by varying space velocity(1(.)10(4)-8(.)10(4) h(-1)), preheat temperature of the feed gas (100-600 degreesC), and ethane-to-oxygen ratio (2-5) in the absence and presence of 15% steam. Space velocity was found to be a significant factor in determining the maximal reaction temperature and hence the extent of thermal pyrolysis. The highest ethylene yield amounted to 56% (S = 71%) achieved at GHSV = 8.3(.)10(4) h(-1) (tau (STP) = similar to 45 ms), C2H6/O-2/N-2 = 2/1/1, and a preheat temperature of 600 degreesC corresponding to a maximal reaction temperature of 940 degreesC. The addition of steam resulted in some decrease of the maximal temperature leading to a decrease in the ethylene yield by ca. 2%. No significant effect of the steam addition on product distribution was observed. (C) 2001 Academic Press.