Comparative studies on isothermal and non-isothermal reduction of haematite in carbon monoxide atmosphere

The reduction behaviour of tungsten oxide has been studied by using temperature programmed reduction (TPR) and X-ray diffraction (XRD). The reduction behavior were examine by nonisothermal reduction up to 900 oC then continued with isothermal reduction at 900 oC for 45 min time under (40% v/v) carbon monoxide in nitrogen (CO in N2) atmosphere. The TPR signal clearly shows one peak attributed to formation of suboxide W18O49 (more) and WO2 (less) observed at 80 min. The reduction product was investigated by varying the holding reaction time. Based on the characterization of the reduction products by using XRD, it was found that, nonisothermal reduction of WO3 at temperature 900 oC partially converted to some W18O49 and WO2 phases. However, after increased the reaction holding time for 45 min, WO3 phases disappeared and converted to WO2 and W metal phases. It is obviously shows that by hold the reduction time could improve the reducibility of the sample oxide. Furthermore, it is suggested that reduction by using CO as reducing agent follows the consecutives steps WO3 → WO2.92 → W18O49 → WO2 → W.

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Comparative studies of the catalytic fluorination of carbon monoxide with elementary fluorine

Journal of the American Chemical Society ◽

10.1021/ja01044a019 ◽

1969 ◽

Vol 91 (16) ◽

pp. 4432-4436 ◽

Cited By ~ 16

Author(s):

Manfred Wechsberg ◽

George H. Cady

Keyword(s):

Carbon Monoxide ◽

Comparative Studies ◽

Elementary Fluorine

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Non-isothermal reduction kinetics of Fe2O3–NiO composites for formation of Fe–Ni alloy using carbon monoxide

Transactions of Nonferrous Metals Society of China ◽

10.1016/s1003-6326(14)63519-6 ◽

2014 ◽

Vol 24 (11) ◽

pp. 3710-3715 ◽

Cited By ~ 10

Author(s):

Bo LI ◽

Yong-gang WEI ◽

Hua WANG

Keyword(s):

Carbon Monoxide ◽

Reduction Kinetics ◽

Isothermal Reduction ◽

Ni Alloy ◽

Kinetics Of

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Study on the Reduction Behavior of Molybdenum Oxide (MoO3) in Carbon Monoxide (CO) Atmosphere

Materials Science Forum ◽

10.4028/www.scientific.net/msf.840.299 ◽

2016 ◽

Vol 840 ◽

pp. 299-304 ◽

Cited By ~ 2

Author(s):

Alinda Samsuri ◽

Tengku Shafazila Tengku Saharuddin ◽

Fairous Salleh ◽

Rizafizah Othaman ◽

Mohamed Wahab Mohamed Hisham ◽

...

Keyword(s):

Carbon Monoxide ◽

Molybdenum Trioxide ◽

Xrd Analysis ◽

Reduction Peak ◽

X Ray Diffraction ◽

Reduction Behavior ◽

Isothermal Reduction ◽

Intermediate Phases ◽

Temperature Programmed ◽

Isothermal Mode

The reduction behavior of molybdenum trioxide (MoO3) by carbon monoxide (CO) has been studied using temperature programmed reduction (TPR) and was characterized using X-ray diffraction spectroscopy (XRD). The TPR result shows that the first reduction peak of MoO3 under 20 vol. % CO in nitrogen started at 530 °C and second reduction peaks observed was at 700 °C. The XRD technique was employed to identify the changes in the sample. It was found that after non-isothermal reduction up to 700 °C, the intermediate phases Mo4O11 were observed. Completed reduction to MoO2 achieved after continued reduction with isothermal mode at 700 °C for 60 minutes. Based on the XRD analysis, it is confirmed that the reduction of MoO3 to MoO2 in CO atmosphere consists of two reduction stages, i) Mo6+ → Mo5+ and ii) Mo5+ → Mo4+. While, CO excess have resulted the formation of molybdenum carbide (Mo2C) rather than formation of metallic molybdenum (Mo).

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Comparative studies of exhaust emission from diesel engine fuelled with diesel fuel and B100 fuel

Combustion Engines ◽

10.19206/ce-2017-321 ◽

2017 ◽

Vol 170 (3) ◽

pp. 126-130

Author(s):

Stanisław KRUCZYNSKI ◽

Marcin ŚLĘZAK ◽

Wojciech GIS ◽

Andrzej ŻÓŁTOWSKI ◽

Maciej GIS

Keyword(s):

Carbon Monoxide ◽

Diesel Engine ◽

Vegetable Oils ◽

Diesel Fuel ◽

Comparative Studies ◽

Exhaust Emission ◽

Chemical Characteristics ◽

Compression Ignition ◽

Compression Ignition Engines ◽

Physical Chemical

The article presents a comparative study of carbon monoxide, hydrocarbons, nitrogen oxides and the mass and number of particulate of diesel engine fulled with diesel and B100. B100 is a biofuel produced from vegetable oils for vehicles with compression-ignition engines. B100 fuel and diesel have similar physical-chemical characteristics which have been analyzed. The research was carried out on an engine dynamometer in four cycles: ESC, ETC, WHSC and WHTC. The article provides an analysis of the research results, preceded by a discussion of the test cycles used.

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Comparative Studies on Acclimatization of Mice to Carbon Monoxide and to Low Oxygen

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1952.169.2.285 ◽

1952 ◽

Vol 169 (2) ◽

pp. 285-294 ◽

Cited By ~ 12

Author(s):

Robert T. Clark ◽

Arthur B. Otis

Keyword(s):

Carbon Monoxide ◽

Comparative Studies ◽

Low Oxygen

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Influence of Cerium Additive on the Reduction Behaviour of Tungsten Oxide under Carbon Monoxide Atmosphere

Materials Science Forum ◽

10.4028/www.scientific.net/msf.888.389 ◽

2017 ◽

Vol 888 ◽

pp. 389-393

Author(s):

Fairous Salleh ◽

Tengku Shafazila Tengku Saharuddin ◽

Alinda Samsuri ◽

Rizafizah Othaman ◽

Mohammad Wahab Mohammad Hisham ◽

...

Keyword(s):

Carbon Monoxide ◽

Reduction Peak ◽

X Ray Diffraction ◽

Reduction Behavior ◽

Remarkable Effect ◽

Isothermal Reduction ◽

Temperature Programmed ◽

Lower Temperature ◽

Metal Phases

The reduction of pure WO3 and Ce/WO3 has been studied by using temperature programmed reduction (TPR), X-ray diffraction (XRD), and FESEM analysis. The reduction behavior were examined by non-isothermal reduction up to 900 oC then continued with isothermal reduction at 900 oC for 45 min under (40% v/v) carbon monoxide in nitrogen (CO in N2) atmosphere. The TPR results shows that reduction peak of Ce/WO3 were shifts to lower temperature as compared with to the pure WO3. In addition, TPR results indicate that addition with ceria give better reducibility compared to pure WO3. Based on the characterization of the reduction products after hold 45 min using XRD, pure WO3 were completely converted to WO2 and W metal phases. While, after addition of Ce to the WO3, the reduction was enhanced to W phases and some suboxide W5O14 and W3O5 with no WO2 phase remained and carbide observed. This is associated to the formation of alloy complex Ce2WO6 which gave remarkable effect to the reduction.

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