Download or read book The Partial Oxidation of Methanol to Formaldehyde Over Molybdenum containing Catalysts written by Tsong-Jen Yang and published by . This book was released on 1982 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Partial Oxidation of Methanol to Formaldehyde Over Sb Mo Oxide Catalysts written by Rafael Alfredo Díaz Real and published by . This book was released on 1991 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The kinetics of the vapor phase air oxidation of methanol to formaldehyde over molybdenum oxide catalysts, antimony oxide catalyst, and their mixtures (both supported and unsupported), at atmospheric pressure and different operating conditions, have been studied in a fixed-bed integral reactor heated by a fluidized sand bath. The effect of various process variables, namely the process temperature (T), the ratio of catalysts to feed flow rate or space time (W/F), and the ratio of methanol fed to air (R), on conversion and yield have been determined. A screening study at varying operating conditions was performed to determine the optimum composition of a Sb$\sb2\rm O\sb4$-MoO$\sb3$ mixture. On the basis of this study a catalyst containing 67% $\rm Sb\sb2O\sb4$-33% MoO$\sb3$ was selected for the detailed kinetic study of oxidation of methanol to formaldehyde. The operating conditions studied were as follows: temperature in the range 623 to 698 K, space times from 5 to 50 $\rm g\sb{cat}/mol\sb{CH\sb3OH}h\sp{-1},$ and methanol to air ratios in the range 0.04 to 0.10 mol$\rm\sb{CH\sb3OH}h\sp{-1}/mol\sb{air}h\sp{-1}.$ This catalyst proved to be highly active and selective to formaldehyde formation. Yields up to $\sim$100% were obtained. Best operating conditions found were obtained at a space time of 27.5 for a methanol/air ratio of 0.06 and a temperature of 698 K. The rate equation for the oxidation of methanol to formaldehyde was derived on the basis of a two-stage redox mechanism$$\eqalign{\rm CH\sb3OH\sb{(g)} + S\sb{ox}\ {\buildrel{k\sb1}\over{\to}}\ &\rm HCHO\sb{(g)} + H\sb2O\sb{(g)} + S\sb{red}\cr\rm O\sb{2\sb{(g)}} + &\rm S\sb{red}\ {\buildrel{k\sb2}\over{\to}}\ S\sb{ox}\cr}$$where S$\rm\sb{ox}$ represents an active site of lattice oxygen and S$\rm\sb{red}$ represents a reduced site of lattice oxygen. The rate equation for the temperature of 648 to 698 K which correlated the data was$$\rm r = {k\sb1P\sb{M}\over 1+{k\sb1P\sb{M}\over 2k\sb2P\sb{O\sb2}}}$$where k$\sb1$ and k$\sb2$ are the temperature dependent rate constants of steps one and two. The equations relating k$\sb1$ and k$\sb2$ with temperature were$$\eqalign{&\rm ln\ k\sb1 = -6.4039-{6.9153\times10\sp3\over T}\cr&\rm ln\ k\sb2 = -3.0154 + {1.8809\times10\sp3\over T}\cr}$$ Several spectroscopic and analytical techniques, viz, electron spin resonance (ESR), x-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), and adsorption studies were used to characterize the catalysts. The surface are of the catalyst used in the kinetic study was 6.1 m$\sp2$/g as determined by the BET method. A preliminary study of the Sb-Mo oxide mixture (load of $\sim$5 wt%) supported on Y zeolite was also carried out. Maximum yield obtained was comparable to that obtained with pure MoO$\sb3.$ A new catalyst has been developed that gave nearly 100% conversion and 100% yield. The industrial potential of this catalyst is very promising.

Download or read book Partial Oxidation of Methanol to Formaldehyde Over Molybdenum tin Oxide Catalysts written by Rowaida George Zoumot and published by . This book was released on 1992 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The vapor phase air oxidation of methanol to formaldehyde was investigated over molybdenum oxide, tin oxide and their mixtures in an integral flow reactor at atmospheric pressure between temperature of 513 and 573 K, a space time of 10-40 hr g-cat/g-mol methanol and a molar ratio of 0.04-0.1 mol CH3OH/mol air. Experiments were done under such conditions that the effects of internal and external heat and mass transfer effects were negligible. The effects of several process variables, temperature, space time and methanol/air ratio on the conversion of methanol and the selectivity of the catalyst for formaldehyde production were determined. The results indicated that the impact of the process variables on the conversion, selectivity and yield of formaldehyde were in the following decreasing order T > W/F > R. A screening study indicated the optimum catalyst composition to be 50% SnO2 and 50% MoO3, while conversion increased with temperature and W/F selectivity decreased. This catalyst proved to be highly active and selective to formaldehyde production. Selectivity and yield of up to about 100% were obtained at 100% conversion at a temperature of 553 K, a space time (W/F) of 40 g-cat/g-mol methanol per hour and a molar ratio (R) of 0.04 mol CH3 OH/mol air. The rate expression r=k1P2M 1+k1P2M2k 2PO2 was deduced assuming a steady-state involving two-stage irreversible oxidation-reduction process. It represented the experimental data satisfactorily. Arrhenius plots of the two rate constants gave activation energies of 31.7 and 18.1 kcal/g-mol.

Download or read book Partial Oxidation of Methanol to Formaldehyde Over Mo Sn Oxide Catalysts written by Rowaida George Zoumot and published by . This book was released on 1992 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Partial Oxidation of Methane to Formaldehyde Over Molybdenum Oxide based Catalysts written by Marianne Rose Smith and published by . This book was released on 1992 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Partial Oxidation of Methanol Over Finely Divided Molybdenum Oxide written by Jong Shik Chung and published by . This book was released on 1984 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Oxidation of Methanol with Air Over Oxide Catalysts written by Wesley Rasmus Peterson and published by . This book was released on 1929 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Partial Oxidation of Methanol on Molybdenum and Vanadium Oxide Catalysts written by Raúl Miranda and published by . This book was released on 1983 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Partial Oxidation of Methanol to Formaldehyde Over an Electrolytic Silver Catalyst written by Geoffrey Ivan Neil Waterhouse and published by . This book was released on 2003 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Kinetics of the Oxidation of Methanol to Formaldehyde Using Iron molybdenum Oxide as a Catalyst written by Noshir Behram Havewala and published by . This book was released on 1962 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book New Frontiers in Catalysis Parts A C written by L. Guczi and published by Elsevier. This book was released on 1993-04-20 with total page 2955 pages. Available in PDF, EPUB and Kindle. Book excerpt: These volumes comprise the proceedings of the major international meeting on catalysis which is held at 4 year intervals. The programme focussed on New Frontiers in Catalysis including nontraditional catalytic materials and environmental catalysis. The contributions cover a wide range of fundamental, applied, industrial and engineering aspects of catalysis. The extensive range of highly efficient industrial techniques for observing and characterizing catalytically important surfaces is evident.The programme covered the following sessions: Mechanism, theory, in situ methods; Catalytic reaction on atomically clean surfaces; Catalytic reaction on zeolites and related substances; New methods and principles for catalyst preparation; Hydrotreatment reactions (HDS, HDN); Characterization of catalysts, application of novel techniques; Selective oxidation; New catalytic aspects of heteropoly acids and related compounds; Reaction of hydrocarbons; Nontraditional catalytic materials; Fuel upgrading; Alkane activation; Acid-base catalysis; New selective catalytic reactons, fine chemicals; Environmental catalysis; Industrial catalysis, deactivation, reactivation; Synthesis from syngas; Electrocatalysis; Photocatalysis.The invited lectures and 433 papers included in these volumes present an update on all areas of catalysis and applications.

Download or read book Methanol Oxidation on Transition Elements Oxides written by Abdulmohsen Alshehri and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Methanol oxidation to formaldehyde is one of the most important industries in our lives; the reaction occurs on catalyst surface in heterogeneous catalysis. Iron molybdate is the current selective catalyst. However, molybdenum volatilises during methanol oxidation and leaving the catalyst with a low molybdenum ratio, which deactivates the catalyst, a 2.2 Mo: 1Fe iron molybdate catalyst was used instead the stoichiometric catalyst, while yield of formaldehyde cannot be 100%. The goal of this study is to find more selective and more productive catalyst than iron molybdate catalyst, the first step is to find another transition element as selective as molybdenum, because molybdenum is the selective part, and iron is the active part, the resulting iron molybdate catalyst is a selective catalyst to formaldehyde near molybdenum and active near iron. Experimentally, catalysts were prepared using co-precipitation method, however, some doped catalysts were papered by incipient wetness impregnation, also sol-immobilization was used to prepare nano-gold particles on the surfaces of few supports. Catalysts characterizations were carried out within several techniques for the surface analysis (XPS) and bulk analysis (XRD), also the surface area was measured by BET equipment. Raman too was used in this study, while micro-reactor was the reactor to determine selectivity and activity of each catalyst. When molybdenum replaced by vanadium, the catalyst yielded 100% formaldehyde at 200 oC; moreover, tungsten was selective. Likewise, iron was replaced by other active metals such as manganese, copper and bismuth, which are active. Nano-gold improved activity when doped on molybdenum oxide and iron molybdate supports.

Download or read book Raman Spectroscopic Studies of Iron molybdenum Oxide Catalysts for the Oxidation of Methanol to Formaldehyde written by James Harvey Wilson (III) and published by . This book was released on 1986 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 1989 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Partial Oxidation of Methanol to Formaldehyde Over Isolated Vanadate Species Supported on High Surface Area Metal Oxides written by Jason Lee Bronkema and published by . This book was released on 2007 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oxidation of Methanol Over Molybdenum Oxide tungsten Oxide Catalyst written by Jain, Satyendra Kumar and published by 1976.. This book was released on 1976 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Oxidation of Methanol Over Molybdenum vanadium Oxide Catalysts microform written by Dosi, Mahendra Kumar and published by National Library of Canada. This book was released on 1971 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: