Carbon monoxide ratios

A mixture of the two reactants carbon monoxide and hydrogen is called synthesis gas and IS prepared by several processes The most widely used route to synthesis gas employs methane (from natural gas) and gives a 3 1 hydrogen to carbon monoxide ratio... 

Conversion to Hydrogen (Water Gas Shift Reaction). Carbon monoxide reacts with water over a catalyst to produce hydrogen and carbon monoxide (25). This reaction is used to prepare high purity hydrogen or synthesis gas with a higher hydrogen-to-carbon monoxide ratio than the feed (eq. 3). 

Fresh feed that has the proper hydrogen carbon monoxide ratio (i.e., slightly above the 3 1 minimum stoichiometric ratio) is mixed with recycle gas and sent through a heat exchanger and into the first catalyst bed, Stage I. The space velocity in Stage I is controlled so that all of the carbon monoxide fed to it is completely converted. The inlet gases are... 

One of the most important, and perhaps the best studied, applications of three-phase fluidization is for the hydrogenation of carbon monoxide by the Fischer-Tropsch (F-T) process in the liquid phase. In this process, synthesis gas of relatively low hydrogen to carbon monoxide ratio (0.6 0.7) is bubbled through a slurry of precipitated catalyst suspended in a heavy oil medium. The F-T synthesis forms saturated and unsaturated hydrocarbon compounds ranging from methane to high-melting paraffin waxes (MW > 20,000) via the following two-step reaction ... 

The thermodynamics of the above reactions are illustrated in Figures 5.6 and 5.7174. Both figures assume a steam-to-methane ratio of 1.0. Figure 5.6 illustrates how the feed and product gases interact when the product gas has a hydrogen-to-carbon monoxide ratio of 3.0. Figure 5.7 illustrates the effects of temperature and pressure on the reactions. As pressure increases, lower conversion can be expected and more methane will not be converted and will be found in the reformer discharge stream. 

Hydroformylation of linear olefins in a conventional cobalt oxo process (see Section 5.3) produces increasing linear-to-branched aldehyde ratios as the carbon monoxide ratio in the gas stream is increased up to 5 MPa (50 atm), but there is little further effect if the reaction mixture is saturated with carbon monoxide. An increasing partial pressure of hydrogen also increases this ratio up to a hydrogen pressure of 10 MPa. As the reaction temperature is increased, the linear-to-branched aldehyde ratios decreases. Solvents in conventional cobalt-catalyzed hydroformylation affect the isomer distribution. In propylene... 

Oxygen-blown ATR with natural gas is used today in very large units that generate a mixture of CO and H2 for the Fischer-Tropsch process or methanol synthesis. This is attractive in part because the units can produce the hydrogen-to-carbon monoxide ratio needed in the synthesis step. Since the heat of reaction is added by combustion with oxygen, the catalyst can be incorporated as a fixed bed that can be scaled up to achieve further benefits of larger plant size in both the... 

Solution. The feed consists of a 2 1 molar ratio of hydrogen-to-carbon monoxide, the same ratio in which they react therefore the hydrogen-carbon monoxide ratio remains constant throughout the process. Thus, it is necessary to calculate the flow rates of only one of the reactants carbon monoxide flow rates are calculated here. The hydrogen flow rate in any stream is twice that of carbon monoxide. Perfect separation between reactants and products is assumed. 

Thermodynamically, the reforming reaction. Equation 3.5.1, shows that the reformer should be operated at die lowest pressure and highest temperature possible. The reforming reaction occurs on a nickel-oxide catalyst at 880 C (1620 "F) and 20 bar, which results in a 25 "C approach to the equihbrium temperature [25,29]. Methane conversion increases by reducing the pressure, but natural gas is available at a high pressure. It would be costly to reduce the reformer pressure and then recompress the synthesis gas later to 100 bar (98.7 atm) for the converter. The steam to carbon monoxide ratio is normally in the range of 2.5 to 3.0 [30]. The ratio favors both the conversion of methane to carbon monoxide and the carbon monoxide to carbon dioxide as indicated by Equations 3.5.1 and 3.5.3. If the ratio is decreased, the methane concentration increases in the reformed gas, but if the ratio is set at three, the unreacted methane is small. The methane is a diluent in the synthesis reaction given by Equation 3.5.2. 

Since HLiCO and LiCOH are intramolecular solvated organolithium species - in contrast to LiH - it is a question of interest, whether oligomerization is still a strongly exothermic process. Therefore again ab initio calculations on HF/6-3 IG level of theory are used to explore geometries and reaction enthalpies of dimers and tetramers, when the lithium to carbon monoxide ratio is 1 1. 

Xue, E., O Keeffe, M., and Ross, J.R.H. Water-gas shift conversion using a feed with a low steam to carbon monoxide ratio and containing sulphur. Catalysis Today, 1996, 30, 107. 

In the Canadian context there need not be a restriction on biomass conversion processes to be self-sufficient and therefore be required to sacrifice carbon to drive the processes, Natural gas and hydro/nuclear electricity are likely to be available on a large scale through to the early decades of the next century. One or all of the following options have been discussed in the context of biomass conversion and in the specific case of methane additions to alter hydrogen to carbon monoxide ratios in syn gas work is presently under way to combine oxygen blown wood gasification with the reforming of natural gas, (5),... 

Generally, in a conventional WGS system a two-step shift is used to obtain high CO conversion rates. In the first high-temperature shift reactor the major part of the CO is converted at high activity, whereas in the second shift reactor the rest of the CO (closely up to the thermodynamic equilibrium) is converted at low temperature and also low activity. Steam to carbon monoxide ratios above the stoichiometric ratio (higher than 2) are generally being used to attain the desired carbon monoxide conversion, but also to suppress carbon formation on certain catalysts. 

However, if electrolysis of water were used to provide oxygen for the gasifier the hydrogen produced at the same time would correct the hydrogen/carbon monoxide ratio. 

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