Syngas methane partial oxidation reaction

Catalytic oxidation reactions on noble metal surfaces are sufficiently fast and exothermic that they can be operated at contact times on the order of one millisecond with nearly adiabatic temperatures of 1000°C. At short contact times and high temperatures complete reaction of the limiting feed is observed, and highly nonequilibrium products are obtained. We summarize experiments where these processes are used to produce syngas by partial oxidation of methane, olefins by partial oxidation of higher alkanes, and combustion products by total oxidation of alkanes. The former are used to produce chemicals, while the latter is used for high temperature catalytic incineration of volatile organic compounds. 

H2) where a complex network, involving secondary reactions of CO2 and H2O with CH4, enhance the yield of H2 and CO so that thermodynamic equilibrium can be reached easily [27]. It can be inferred that, like the oxidation of methane to syngas, the partial oxidation of methanol with a CH3OH/O2 ratio near to the stoichiometric value (ca. 2/1) operating with an optimum residence time and temperature can reach very high yields also approaching thermodynamic equilibrium. 

Use of the Reaction to Modify the Membrane and Improve Driving Force -The use of dense oxide membranes to feed O2 to partial oxidation reactions is limited by the need for high temperatures to obtain reasonable permeation rates. The potential exists for selectivity gains and the control of heat effects. One application where dense membranes have a clear role to play is in methane activation. In particular, the partial oxidation of methane to syngas. 

These estimates give only an upper limit of oxygen permeation rate because surface exchange reactions may result in some suppression of the overall transport. For the conditions typical for syngas generation (pO2=0.21 atm, pOj = 10 atm, 950°C), the results for the membranes with L = 0.1cm and different chromium contents are shown in Fig. 3. In the calculations at high pressures the ion conductivity values were assumed to be nearly equal to those at low pressures. Fig. 2. It is seen that the permeation rate in chromium doped samples is smaller than in the parent ferrite. Nonetheless, it may achieve a value of about 4 ml cm min in the sample with y = 1, which corresponds to the syngas production rate of about 20-25 ml-cm -min in the methane partial oxidation process. In combination... 

Gasification of Methane and oxygen to syngas, a non-catalytic partial oxidation reaction taking place at temperatures above 1300°C... 

The partial oxidation reaction of methane to syn is mildly exothermic, in contrast to hi fy endothermic steam reforming. It could produce stoichiometric syngas for methanol synthesis in one step. It is an ideal process for producing methanol syn. Effective catalysts are needed to carry the reaction selective at mild temperatures. A recent finding by researchers at the University of Oxford indicated that the reaction could be carried out selective at 775°C (97+% selectivity at 94% conversion) using lanthanide ruthenium oxide or alumina-supported ruthenium catalysts, in contrast to more than 1200°C in conventional processes [62],... 

Synthesis gas, a mixture of CO and o known as syngas, is produced for the oxo process by partial oxidation (eq. 2) or steam reforming (eq. 3) of a carbonaceous feedstock, typically methane or naphtha. The ratio of CO to may be adjusted by cofeeding carbon dioxide (qv), CO2, as illustrated in equation 4, the water gas shift reaction. 

The two mechanisms proposed to account for the partial oxidation of methane to syngas may be dedgnated as the IPO (Indirect Partial Oxidation) mechanism and the DPO (Direct Partial Oxidation) mechanism. The IPO mechanism was proposed by Prette et al [16] and Lunsford et al [12]. They think CO and H2 are the products of indirect reaction, the overall reaction of the POM reaction is composed of three different reactions... 

Two conqiletely different behaviors of oxidative transformation of methane, namely the Oxidative Coupling of Methane to C2 Hydrocarbons(OCM) and the Partial Oxidation of Methane to Syngas(POM), were performed and related over the nickel-based catalysts due to different modification and different supports. It is concluded that the acidic property favors keeping the reduced nickel and the reduced nickel is necessary for POM reaction, and the bade property frvors keeping the oxidized nickel and the oxidized mckel is necessary for OCM reaction. POM and OCM reactions proceed at different active sites caused by different... 

Gas-phase reaction 8 [CP 8] Syngas generation by partial oxidation of methane... 

One example of membrane reactors is oxidation, in which oxygen from one phase diffuses from one side of an oxygen-permeable membrane to react with a fuel on the other side of the membrane. This avoids a high concentration of O2 on the fuel side, which would be flammable. A catalyst on the fuel side of the membrane oxidizes the fuel to partial oxidation products. One important process using a membrane reactor is the reaction to oxidize methane to form syngas,... 

Much recent research (7-5) has been devoted to converting methane to products that are more easily transported and more valuable. Such more valuable products include higher hydrocarbons and the partial oxidation products of methane which are formed by either direct routes such as oxidative coupling reactions or indirect methods via synthesis gas as an intermediate. The topic of syngas formation by oxidation of CH4 has been considered primarily from an engineering perspective (7-5). Most fundamental studies of the direct oxidation of CH4 have dealt with the CH4 + O2 reaction system in excess O2 and at lower temperatures (6-10). 

The synthesis of intermediates and monomers from alkanes by means of oxidative processes, in part replacing alkenes and aromatics as the traditional building blocks for the chemical industry [2]. Besides the well-known oxidation of n-butane to maleic anhydride, examples of processes implemented at the industrial level are (i) the direct oxidation of ethane to acetic acid, developed by Sabic (ii) the ammoxidation of propane to acrylonitrile, developed by INEOS (former BP) and by Mitsubishi, and recently announced by Asahi to soon become commercial (iii) the partial oxidation of methane to syngas (a demonstration unit is being built by ENI). Many other reactions are currently being investigated, for example, (i) the... 

The ATR (Autothermal Reforming) process makes CO-enriched syngas. It combines partial oxidation with adiabatic steam-reforming and is a cost-effective option when oxygen or enriched air is available. It was developed in the late 1950 s for ammonia and methanol synthesis, and then further developed in the 1990 s by Haldor Topspe2. The difference between Steam Methane Reforming (SMR) and ATR is in how heat is provided to activate the endothermic steam reforming reaction. In SMR, the catalyst is contained in tubes that are heated by an external burner. 

On the other hand Otsuka et al. found that for ceria both surface and bulk oxygen ions participate to the partial oxidation of methane [49]. When oxygen is missing there is syngas H2 + CO formation. However this reaction occurs only at high temperature close to 750°C ... 

Burke, N. and David, T. Coke formation during high pressure catalytic partial oxidation of methane to syngas. Reaction Kinetics and Catalysis Letters, 2005, 84, 137. 

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