Methane + iso-butane

Butanes Normal butane Tri-methyl methane (Iso-butane)... 

An example of the separation of a methane-iso-butane-n-butane mixture with splitless injection of 0.5 ml of the sample into a glass capillary column with a silica layer is given in paper [26]. The analysis time is less than 1 min. Incidentally, splitless injection of a sample was already used in an earlier period of adsorption capillary column development (see, for example, Fig. 3-4 [70]). 

Rather than using the isotopic composition of methane alone James (1983, 1990) and others have demonstrated that carbon isotope fractionations between the hydrocarbon components (particularly propane, iso-butane and normal butane) within a natural gas can be used with distinct advantages to determine maturity, gas-source rock and gas-gas correlations. With increasing molecular weight, from Ci to C4, a enrichment is observed which approaches the carbon isotope composition of the source. 

Two French workers, Villard and de Forcrand, were the most prolific researchers of the period before 1934, with over four decades each of heroic effort. Villard (1888) first determined the existence of methane, ethane, and propane hydrates, de Forcrand (1902) tabulated equilibrium temperatures at 1 atm for 15 components, including those of natural gas, with the exception of iso-butane, first measured by von Stackelberg and Muller (1954). 

As simple hydrates, methane, and hydrogen sulfide can stabilize the 512 cavities of structure I (size ratios of 0.86 and 0.90, respectively) and they can occupy all the large 51262 cavities of si (size ratios of 0.74 and 0.78, respectively). Ethane occupies the 51262 cavities of structure I with a ratio of 0.94. Propane and iso-butane each occupy the 51264 cavities of structure II with a size ratio of 0.94 and 0.98, respectively. 

Of the natural gas components that form simple hydrates, nitrogen, propane, and iso-butane are known to form structure II. Methane, ethane, carbon dioxide, and hydrogen sulfide all form si as simple hydrates. Yet, because the larger molecules of propane and iso-butane only fit into the large cavity of structure II, natural gas mixtures containing propane and iso-butane usually form structure II hydrate (see Section 2.1.3.3 in the subsection on structural changes in binary hydrate structure). 

Thus, methane is the main hydrocarbon component of petroleum gases with lesser amounts of ethane, propane, butane, iso-butane and some C5+ light hydrocarbons. Other gases, such as hydrogen, carbon dioxide, hydrogen sulfide and carbonyl sulfide, are also present. 

Fig. 6 Yardstick-plot (Eq. 1) of N220 (triangle) and a graphitized N220g (filled circles) with adsorption cross section a determined from the bulk liquid density p (Eq. 2) 1 argon, 2 methane, 3 ethane, 4 propane, 5 iso-butane, 6 n-butane The slopes yield for N220 ds=2.56 0.04, for N220g ds=2.32 0.03. Adsorption temperatures and densities p are chosen according to the evaporation points of the gases at 1000 mbar...

The reaction results in the formation of gases such as methane, ethane, ethylene, propane, propylene, iso-butane, n-butane, hydrogen gaseous petrol, kerosene, diesel, heavy oil (CLO). The gases are subsequently allowed to pass through a condenser. 

Okabe and Becker examined the photolysis of -butane at 1470 and 1236 A, with and without NO as an inhibitor. Their thorough product analysis, which gave an excellent material balance, showed that the products for the uninhibited reaction are hydrogen, methane, acetylene, ethylene, ethane, propene, propane, butene-1, cis- and tranf-butene-2, iso- and n-pentane, hexanes and small amounts of iso-butane and allene. The most important reactions occurring in the photolysis are... 

Figure 2 Flux of methane ( ), ethane, ( ), propane ( ), n-buiane ( ), and iso>butane (A) through a silicalite-1 membrane as a function of partial pressure on the feed side (T = 298 K, = 100 kPa). Feed was composed of hydrocarbon and balance helium sweep gas used was helium. There was no absolute pressure difference across the membrane. (Adapted from Ref. 14.)...

Figure 3 Permeability of methane (—), ethane (—), n-butane and iso-butane (-...

Table 1 shows the results of the hydrogenation of carbon dioxide over various composite catalysts. All the composite catalysts except for the Cu-Zn-Al/HY gave considerable amounts of olefins and exhibited high selectivity of iso-butane (32-39%) with low content of methane (2-7%). For the Fe-based composite catalysts, the selectivities of hydrocarbons (31.1-46.8%) depended on the third metal added to the Fe-Zn catalyst, while the conversions of CO2 were relatively constant at 15-18%. In the series of Fe-Zn-M( 1 2 1 )/HY composite catalysts, the highest yield of iso-butane was observed in the Zr-containing composite catalyst (2.5 C-mol%). The selectivity of hydrocarbons (46.8%) and the yield of iso-butane (3.0 C-mol%) for Fe-Zn-Zr(l l l)/HY, as far as we know, are the best for the selective production of iso-butane from carbon dioxide and hydrogen. 

The geochemical data come from 239 shallow probe (1.2 metre, 4 feet) soil-gas samples collected on 500 - 1000 m grids placed directly over these two fields, with 95 sites over Filo Morado and 144 sites over Loma de La Lata. The free soil gases were analysed for methane, ethane, ethylene, propane, propylene, iso-butane and normal butane by gas chromatography using a flame ionisation detector. 

In order to proof the applicability of the mentioned approaches and to study the incorporation of different gases in the hydrate lattices depending on their properties (solubility, dimension, etc.) we performed investigations on gas hydrates which have been synthesized from gas mixtures as a free gas phase and water. The gas mixtures contain besides methane the isomers of butane (n-butane iso-butane) and pentane (iso-pentane, 2,2-dimethylpropane), respectively. The exact compositions of the gas mixtures are given in table 1. The experiments and results are described in detail in the diploma thesis of M. Luzi. ... 

Natural gas liquids are products other than methane from natural gas ethane, butane, iso-butane, and propane. Natural gasoline may also be included in this group. 

The first and most important aspect of gaseous testing is the measurement of the volume of gas (ASTM D-1071). In this test method, several techniques are described and may be employed for any purpose where it is necessary to know the quantity of gaseous fuel. In addition, the thermophysical properties of methane (ASTM D-3956), ethane (ASTM D-3984), propane (ASTM D-4362), n-butane (ASTM D-4650), and iso-butane (ASTM D-4651) should be available for use and consultation (see also Stephenson and Malanowski, 1987). 

In the present study, silica-coated Pt metal particles were prepared by the methods using microemulsion systems. In addition, the silica-coated Pt catalysts were applied to the oxidation of hydrocarbons, especially to the competitive oxidation of methane and other higher hydrocarbons (ethane, propane and iso-butane) with gaseous oxygen. We would report the specific catalytic performance of silica-coated Pt metals for the reactant selectivity. 

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