01669nas a2200229 4500008004100000022001400041245011000055210006900165260010600234300001400340490000700354520074500361653002401106653003801130653002601168653003501194653002401229653001201253100002601265700002101291856012701312 2005 eng d a0009-250900aKinetics of the complete combustion of dilute propane and methyl ethyl ketone over Cr-doped ZrO2 catalyst0 aKinetics of the complete combustion of dilute propane and methyl aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAR a1575-15810 v603 a

The kinetics of the complete combustion of propane and methyl ethyl ketone (MEK) at very low concentration in air (0.45 and 0.4 mol% in air, respectively) over Cr-doped ZrO2 (cubic) catalyst (Cr/Zr = 0.25) at different temperatures (485-673 K) in the kinetic control regime have been investigated. The combustion rate data could be fitted well to both the power law and redox (Mars-Van Krevelen) models. From the power law model, the apparent activation energy for the combustion of propane and MEK has been found to be 16.5 and 13.2 kcal mol(-1), respectively. Among the two models, the redox one, however, gave a better fit to the kinetic data for both the combustion of propane and MEK. (C) 2004 Elsevier Ltd. All rights reserved.

10acombustion kinetics10acombustion of methyl ethyl ketone10acombustion of propane10aCr-doped ZrO2 (cubic) catalyst10amethyl ethyl ketone10apropane1 aChoudhary, Vasant, R.1 aDeshmukh, G., M. uhttp://library.ncl.res.in/content/kinetics-complete-combustion-dilute-propane-and-methyl-ethyl-ketone-over-cr-doped-zro2-001645nas a2200169 4500008004100000022001400041245010000055210006900155260007100224300001000295490000700305520097100312100002601283700002101309700001901330856012601349 2005 eng d a0887-062400aKinetics of the complete combustion of dilute propane and toluene over iron-doped ZrO2 catalyst0 aKinetics of the complete combustion of dilute propane and toluen a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJAN a54-630 v193 a

The kinetics of the complete combustion of propane and toluene at very low concentrations in air (0.45 and 0.3 mol % in air, respectively) over iron-doped ZrO2 (cubic) catalyst (Fe/Zr = 0.25) at different temperatures (598-723 K) in kinetic control regime have been investigated. The combustion rate data could be fitted very well to both the power-law and redox (Mars-Van Krevelen) models. However, the redox model provided a better fit to the kinetic data for the propane combustion. It also showed a better fit to the toluene combustion data at the lower temperatures (623 K). The reaction order (with respect to the hydrocarbon), apparent activation energy, and frequency factor (from the power-law model) for the propane combustion were 0.96 (average), 21.16 kcal/mol, and 4.67 x 10(5) Mol g(-1) h(-1) kPa(-n), respectively, and those for the toluene combustion were 0.77 (average), 26.08 kcal/mol, and 1.48 x 10(7) mol g(-1) h(-1) kPa(-n), respectively.

1 aChoudhary, Vasant, R.1 aDeshmukh, G., M.1 aMishra, D., P. uhttp://library.ncl.res.in/content/kinetics-complete-combustion-dilute-propane-and-toluene-over-iron-doped-zro2-catalyst-001479nas a2200205 4500008004100000022001400041245011900055210006900174260009800243300001200341490000700353520062500360653003800985653002601023653002701049100002601076700002101102700002101123856012901144 2005 eng d a0268-257500aLow temperature complete combustion of dilute toluene and methyl ethyl ketone over Mn-doped ZrO2 (cubic) catalysts0 aLow temperature complete combustion of dilute toluene and methyl aTHE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLANDbJOHN WILEY & SONS LTDcAUG a934-9380 v803 a

Combustion of dilute toluene and methyl ethyl ketone over Mn-doped ZrO2 catalysts prepared using different precipitating agents, such as tetra-alkyl ammonium hydroxides and NH4OH, having Mn/Zr ratios from 0.05 to 0.67, and calcined at different temperatures has been thoroughly investigated. The Mn-doped ZrO2 catalyst shows high toluene or methyl ethyl ketone combustion activity, particularly when its ZrO2 is in cubic form, when its Mn/Zr ratio is close to 0.2, and when it is prepared using tetra-methyl ammonium hydroxide as a precipitating agent and calcined at 773 K. (c) 2005 Society of Chemical Industry.

10acombustion of methyl ethyl ketone10acombustion of toluene10aMn-doped ZrO2 catalyst1 aChoudhary, Vasant, R.1 aDeshmukh, G., M.1 aPataskar, S., G. uhttp://library.ncl.res.in/content/low-temperature-complete-combustion-dilute-toluene-and-methyl-ethyl-ketone-over-mn-doped-001896nas a2200169 4500008004100000022001400041245018300055210006900238260007100307300001400378490000700392520113200399100002601531700002101557700002101578856012701599 2005 eng d a0013-936X00aLow-temperature complete combustion of a dilute mixture of methane and propane over transition-metal-doped ZrO2 catalysts: effect of the presence of propane on methane combustion0 aLowtemperature complete combustion of a dilute mixture of methan a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAPR a2364-23680 v393 a

Complete combustion of dilute methane alone or a dilute mixture of methane and propane over transition-metal (viz. Mn, Co, Cr, Fe, and Ni)-doped ZrO2 (cubic) catalysts at different temperatures (523-873 K) and a space velocity of 51 000 CM3 center dot g(-1)center dot h(-1) has been investigated for controlling methane and propane emissions from exhaust gases. The catalysts are compared for their catalytic ignition temperature and activity in the combustion of propane and methane in the presence of each other. The methane combustion activity of all the catalysts is strongly influenced by the presence of propane; it is decreased markedly. In the combustion of mixed methane and propane the Mn-doped ZrO2 and Cr-doped ZrO2 catalysts show the highest activity in the combustion of methane and propane, respectively; the Ni-doped ZrO2 shows the lowest activity in both cases. In the combustion of mixed methane and propane the propane combustion is enhanced but the methane combustion retarded when the Cr-doped ZrO2 and Mn-doped ZrO2 catalysts in a 1:1 ratio are used together in different ways (mixed or in layers).

1 aChoudhary, Vasant, R.1 aDeshmukh, G., M.1 aPataskar, S., G. uhttp://library.ncl.res.in/content/low-temperature-complete-combustion-dilute-mixture-methane-and-propane-over-transition-0