Hydrogen methane and

The reader might wish to check that if the temperature of the phase split is increased or its pressure decreased, the separation between hydrogen, methane, and the other components becomes worse. 

The conversion takes place at high temperature (820-850°C) and very short residence time (hundredth of seconds) in the presence of steam. The by-products are hydrogen, methane and a highly aromatic residual fuel-oil. 

Steam Reforming Processes. In the steam reforming process, light hydrocarbon feedstocks (qv), such as natural gas, Hquefied petroleum gas, and naphtha, or in some cases heavier distillate oils are purified of sulfur compounds (see Sulfurremoval and recovery). These then react with steam in the presence of a nickel-containing catalyst to produce a mixture of hydrogen, methane, and carbon oxides. Essentially total decomposition of compounds containing more than one carbon atom per molecule is obtained (see Ammonia Hydrogen Petroleum). 

Dehydrogenation of isobutane to isobutylene is highly endothermic and the reactions are conducted at high temperatures (535—650°C) so the fuel consumption is sizeable. Eor the catalytic processes, the product separation section requires a compressor to facHitate the separation of hydrogen, methane, and other light hydrocarbons from-the paraffinic raw material and the olefinic product. An exceHent overview of butylenes is avaHable (81). 

The highly exothermic reaction has already been mentioned. It is particularly important to realise that at the elevated temperatures employed other reactions can occur leading to the formation of hydrogen, methane and graphite. These reactions are also exothermic and it is not at all difficult for the reaction to get out of hand. It is necessary to select conditions favourable to polymer formation and which allow a controlled reaction. 

The density of a vapour or gas at eonstant pressure is proportional to its relative moleeular mass and inversely proportional to temperature. Sinee most gases and vapours have relative moleeular masses greater than air (exeeptions inelude hydrogen, methane and ammonia), the vapours slump and spread or aeeumulate at low levels. The greater the vapour density, the greater the tendeney for this to oeeur. Gases or vapours whieh are less dense than air ean, however, spread at low level when eold (e.g. release of ammonia refrigerant). Table 6.1 ineludes vapour density values. 

Several coimiion substances amenable to unconfincd vapor cloud explosions are hydrogen, methane, and liquefied natunil gas (LNG). 

Safety-Related Properties of Hydrogen, Methane, and Gasoline... 

Synthesis gas is a mixture of carbon monoxide, hydrogen, methane, and some noncombustible gases. A certain... 

The gases resulting from the irradiation of PDMS have been reported in the literature [395] and consist entirely of hydrogen, methane, and ethane. The yield has been found to be proportional to the degree of cross-linking since double bonds cannot be formed. 

Temporal evolution of the flame brush thickness for the previously described mixtures of hydrogen, methane, and propane with air. (Reproduced from Renou, B. and Boukhalfa, M., Combust. Set. Technol., 162, 342 2001. With permission. Figure 2, p. 353, copyright Gordon Breach Science Publishers (Taylor and Francis editions).)... 

Table 8.10. Theoretical efficiency for converting hydrogen, methane, and methanol into power in a fuel cell.

MRG [Methane rich gas] A catalytic steam-reforming system, similar to the classic syngas reaction of steam with a hydrocarbon mixture, but yielding hydrogen, methane, and carbon monoxide in different proportions. The system is thermodynamically balanced,... 

The major volatile product from the irradiation of Bis-A PSF at 150°C was sulfur dioxide, which was produced with G(SO ) 0.146. This is consistent with previous measurements at 30°C, 125°C and 220°C (1,2). Other volatile products observed were hydrogen, methane, and carbon dioxide. The G values for the various gaseous products are compared with literature results for irradiation at 30 C in Table II. 

Table 9.1. Physical properties of hydrogen, methane, and n-heptane at the triple point, the boiling point and the critical point, and under standard conditions...

Table 11.2. Safety-relevant physical and chemical properties of hydrogen, methane and n-heptane...

The mixture to be separated is fed to the centre of the column down which activated carbon moves slowly. Immediately above the feed, the rising gas is stripped of ethylene and heavier components leaving hydrogen, methane and any non-adsorbed gases to be discharged as a top-product. The adsorbent with its adsorbate continues down the column into an enriching section where it meets an upwards stream of recycled top-product. The... 

As part of the same study selectivity data were provided at 10-100 kPa partial pressures of n-butane at 0-17% conversion over HZSM-5 [90]. With increase in pressure and conversion secondary reactions started to occur. These results are also summarized in Table 13.6. The lowered selectivity to hydrogen, methane and ethane was attributed to increasingly less favorable conditions for monomolecular cracking. The dramatic increase in selectivity to propane which was absent at zero conversion, along with decrease in propylene was considered as signature for bimolecular cracking. More specifically, it was suggested that hydride transfer... 

Figure 3. Theoretical open-circuit potential as a function of conversion to total oxidation of hydrogen, methane, and n-butane at 973 K.

Finally, it is of interest, not only to the student of industrial archelogical history, but also to the modern technologist, to refer to coal gasification. A few decades ago the gasification of coal provided a means of supplying communities with coal gas, a mixture of hydrogen, methane and carbon monoxide, which could be ignited in burners and used as a domestic or industrial source of heat. With the discovery of natural gas... 

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