Carbon Dioxide Hydrocarbons

Experimental investigations into binary systems containing carbon dioxide and light hydrocarbons are summarized in table 3A.2. 

Among the interesting equilibria observed in these systems is that ethane and carbon dioxide exhibit azeotropy. This makes separation 

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Conversion Processes. Most of the adsorption and absorption processes remove hydrogen sulfide from sour gas streams thus producing both a sweetened product stream and an enriched hydrogen sulfide stream. In addition to the hydrogen sulfide, this latter stream can contain other co-absorbed species, potentially including carbon dioxide, hydrocarbons, and other sulfur compounds. Conversion processes treat the hydrogen sulfide stream to recover the sulfur as a salable product. 

The displacing fluid may be steam, supercritical carbon dioxide, hydrocarbon miscible gases, nitrogen or solutions of surfactants or polymers instead of water. The VSE increases with lower mobility ratio values (253). A mobility ratio of 1.0 is considered optimum. The mobility of water is usually high relative to that of oil. Steam and oil-miscible gases such as supercritical carbon dioxide also exhibit even higher mobility ratios and consequent low volumetric sweep efficiencies. 

McHugh, M. A. Yogan, T. J. Three-Phase Solid-Liquid-Gas Equilibria for Three Carbon Dioxide-Hydrocarbon Solid Systems, Two Ethane-Hydrocarbon Solid Systems, and Two Ethylene-Hydrocarbon Solid Systems. J. Chem. Eng. Data 1984, 29, 112-115. 

The carbon di oxi de/lemon oil P-x behavior shown in Figures 4, 5, and 6 is typical of binary carbon dioxide hydrocarbon systems, such as those containing heptane (Im and Kurata, VO, decane (Kulkarni et al., 1 2), or benzene (Gupta et al., 1 3). Our lemon oil samples contained in excess of 64 mole % limonene so we modeled our data as a reduced binary of limonene and carbon dioxide. The Peng-Robinson (6) equation was used, with critical temperatures, critical pressures, and acentric factors obtained from Daubert and Danner (J 4), and Reid et al. (J 5). For carbon dioxide, u> - 0.225 for limonene, u - 0.327, Tc = 656.4 K, Pc = 2.75 MPa. It was necessary to vary the interaction parameter with temperature in order to correlate the data satisfactorily. The values of d 1 2 are 0.1135 at 303 K, 0.1129 at 308 K, and 0.1013 at 313 K. Comparisons of calculated and experimental results are given in Figures 4, 5, and 6. 

The model used combines two equations of state and an excess function. It has been already developed to represent the thermodynamic properties of carbon dioxide-hydrocarbons mixtures [1]. 

The vegetable matter and animal compounds (and us) decay after death into carbon compounds that bacteria recycle into carbon dioxide, hydrocarbon oils and gases, but the rate at which these fossil fuels form is extremely slow and it takes thousands of years to produce coal and oil. 

C. Chen, and T. Hong, The role of hydrogen in diamond synthesis from carbon dioxide-hydrocarbon gases by microwave plasma chemical vapor deposition, Sutf. Coat Technol, 54-55(l-3) 368-373 (1992)... 

Figure 5. RK interaction parameters for carbon dioxide-hydrocarbon systems paraffin hydrocar-...

HAZARD RISK decomposition of fiberglass emits carbon monoxide, carbon dioxide, hydrocarbons and water decomposition of rockwool produces dust suppressant oil additive decomposition of dust suppressant oil additive emits carbon monoxide NFPA Code not available. 

EXPLOSION and FIRE CONCERNS flammable NFPA rating Health 3, Flammability 4, Reactivity 0 flashback along vapor trail may occur explosive if ignited in a confined area aqueous solutions are flammable unless extensively diluted incompatible with fluorine, maleic anhydride, and acrylaldehyde heating to decomposition emits carbon monoxide, carbon dioxide, hydrocarbons, toxic amine vapors, and toxic oxides of nitrogen use water spray, dry chemical, or foam for firefighting purposes. 

Heterogeneous catalysis is also utilized in the catalytic converters in automobile exhaust systems. The exhaust gases, containing compounds such as nitric oxide, carbon monoxide, and unburned hydrocarbons, are passed through a converter containing beads of solid catalyst (see Fig. 12.16). The catalyst promotes the conversion of carbon monoxide to carbon dioxide, hydrocarbons to carbon dioxide and water, and nitric oxide to nitrogen gas to lessen the environmental impact of the exhaust gases. However, this beneficial catalysis can, unfortunately, be accompanied by the unwanted catalysis of the oxidation of SO2 to SO3, which reacts with the moisture present to form sulfuric acid. 

The steam-carbon dioxide-hydrocarbon conversion is conducted over a catalyst such as nickel (oxide) on alumina. This type of catalyst can be purchased in quite similar composition from a number of catalyst vendors. In the case in which the feed stock is processed over a catalyst as in steam-hydrocarbon reforming, it is essential that the gas be purified, at least to some extent, prior to its passage over the reforming catalyst, particularly if the catalyst is of the typical composition of supported and promoted nickel (oxide). In steam hydrocarbon reforming, the methane (natural gas) is usually detoxified using an adsorbent such as carbon on which is impregnated suitable chemical adsorbents such as elemental iron or copper. There are at least two of these metallized carbon desulfurizers in parallel with one on... 

Plasticization behaviour induced by condensable gases and vapours (e.g. carbon dioxide, hydrocarbons and other organic vapours) in polymer membranes is stiQ a painful problem in polymeric membrane-based gas separation applications [27,28]. Recently, novel hyperbranched polyimides were prepared from telechelic polyimides and an attempt was made to improve its gas separation performance and physical stability by obtaining plasticization-resistant materials [29-33] (see e.g. Chapters 4, 6 and 7 of this book). 

Substances considered in a compilation of the thermodynamic properties of refrigerants include hydrogen, parahydrogen, helium, neon, nitrogen, air, oxygen, argon, carbon dioxide, hydrocarbons (e.g. methane, ethane, propane, butane, isobutane, ethylene, and propene), and fluoro-and fluoro-chloro-hydrocarbons. Properties listed include those for the liquid and saturated vapour, superheated vapour, and unsaturated vapour. In addition, pressure-enthalpy, and in some instances pressure-entropy, diagrams are provided. 

The value finally used was close to those for other carbon dioxide hydrocarbon systems listed in Table 7.1. 

One final thing to point out is that when highly reactive gases are used, the purity of the gas is not so critical because the impurity is almost insignificant in determining the ion-molecule reaction mechanism. On the other hand, with collision and low-reactivity gases that contain impurities, such as carbon dioxide, hydrocarbons, or water vapor, the impurity could be the dominant reaction pathway as opposed... 

Sorption-enhanced polymer membranes are beneficial to obtain superior permeability as well as advanced selectivity especially for carbon dioxide, hydrocarbons and VOCs because condensable gas molecules are easier to be adsorbed on the polymer surface." Recent research has focused on incorporating ethylene oxide into a polymer backbone, which has unique interaction with quadruple momentum of carbon dioxide poly(ethylene oxide) (PEO), cross-linked PEO, PEO-based block copolymers such as poly(ethylene oxide-Z)-amide) (Pebax), poly(ethylene oxide- -butylene terephthalate) (PEO-6-PBT)." ... 

Carbon dioxide/ hydrocarbons Carbon dioxide Enhanced oil recovery... 

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