Hydrocarbons schematic representation

Fig. 12. A, Schematic representation of parallel arrays of polynuclear aromatic hydrocarbon molecules in a mesophase sphere. B, a) isolated mesophasc spheres in an isotropic fluid pitch matrix b) coalescence of mesophase c) structure of semi-coke after phase inversion and solidification.

Fig. 2. Schematic representation of selected hydrocarbon chains in the crystalline and the amorphous regions of polyethylene, respectively. For ensembles of chains uniformly distributed around the dashed lines the deuterons from planar and conical distributions as indicated...

Figure 9.6. Schematic representation of the catalytic cycle for the hydrodesulfurization of a sulfur-containing hydrocarbon (ethane thiol) by a sulfur vacancy on M0S2 The C2H5SH molecule adsorbs with its sulfur atom towards...

The pulse technique may also be conveniently extended to include stages of reactant preparation. Figure 9 shows a schematic representation of a pulse reactor system recently used by Gault et al. (81), which includes stages for alcohol (the reactant precursor) dehydration and subsequent olefin hydrogenation, the resulting saturated hydrocarbon being the material of catalytic interest. A method has been described (82) which allows the use of a pulse reactor at above atmospheric pressure. 

Finally, we have designed and synthesized a series of block copolymer surfactants for C02 applications. It was anticipated that these materials would self-assemble in a C02 continuous phase to form micelles with a C02-phobic core and a C02-philic corona. For example, fluorocarbon-hydrocarbon block copolymers of PFOA and PS were synthesized utilizing controlled free radical methods [104]. Small angle neutron scattering studies have demonstrated that block copolymers of this type do indeed self-assemble in solution to form multimolecular micelles [117]. Figure 5 depicts a schematic representation of the micelles formed by these amphiphilic diblock copolymers in C02. Another block copolymer which has proven useful in the stabilization of colloidal particles is the siloxane based stabilizer PS-fr-PDMS [118,119]. Chemical... 

Fig. 1 Schematic representation of a globular micelle O, hydrophilic head group VvV, hydrocarbon tail...

Fig. II. (a) Schematic representation of hydrocarbons adsorbed on the [111] plane of platinum. Intersections of the lines of triangular net denote positions of the centers of platinum atoms. (1) Cyclohexane (2) all-cis conformation of cij-l,3,5-hexatriene (3) transoid conformations of cis- and trans-1,3,5-hexatriene (S4). (b) Adsorption configurations of acetylene and ethylene found most probable according to LEED studies 141).

The critical locus shown in Figure 14.9 is only one (probably the simplest) of the types of critical loci that have been observed. Scott and van Konynen-burg10 have used the van der Waals equation to predict the types of critical loci that may occur in hydrocarbon mixtures. As a result of these predictions they developed a scheme that classifies the critical locus into one of five different types known as types I to type V.1 A schematic representation of these five types of (fluid-I-fluid) phase equilibria is shown in Figure 14.10. In the figure, the solid lines represent the vapor pressure lines for the... 

Figure 4.28 Schematic representation of a biological cell membrane. A bimolecular layer of phospholipid with hydrocarbon chains orientated to the interior and hydrophilic groups on the outside is penetrated by protein (shaded areas). Protein is also found adsorbed at the membrane surface...

Fig. 3.1. Schematic representation of normal micelle (M) in water, a soft-core reverse micelle (RM) and hard-core reverse micelles (RM) in hydrocarbon formulation, ( AAAO ) detergent molecule...

Figure 2. Schematic representation of inhomogeneous broadening and relative energy levels of and Lb states (a) under vacuum, (b) in nonpolar hydrocarbon solvent, (c) in polar water at the instant of absorption, and (d) in polar water after certain-time solvation [55],...

Figure 18. Left Schematic representation of the concept for probing different layers of water near lipid-water interfaces through anchoring hydrocarbon tails of a series of Trp-alkyl ester probes into lipids. Right Normalized steady-state fluorescence emissions from four Trp probes. Note the correlation between emission maxima and their hydrophobicity.

Eig. 2. A two-dimensional schematic representation of the regions of a spherical ionic micelle. The counterions (x), the head groups ( ), and the hydrocarbon chains (naxs/v) are schematically indicated to denote their relative locations but not their number, distribution, or configuration. 

Fia. 14. Schematic representation of the possible modes of interaction in functional micelles. The + and — signs indicate the charge on the head group, n, n m and m represent the number of carbon atoms in the hydrocarbon chain, and Fs and Fg a,re the nucleophilic and substrate functional groups. 

Figures 1.6 and 1.7 offer a schematic representation of units of the Texaco and Shell type, whose special feature is to recover the carbon formed by washing with tvater, and then to extract the sludge obtained with naphtha. The extract can then be homogenized with the feed and thus sent directly to the partial oxidation reactor (Shell version), or previously treated by stripping by reboiling in the presence ofheavier hydrocarbons, such as fiiel oil or crude oil, in order to separate and recycle the naphtha (Texaco version).

FIGURE 7.11 A schematic representation of 4c-3e system geometries established within hydrocarbon cages. 

Assuming BEP-type relationships to be valid, we can make a prediction of the selectivity of fhe Fischer-Tropsch reaction as a function of the M—C bond energy. In Figure 10, a schematic representation is given of the relative rates of production of particular groups of Fischer-Tropsch products as a function of fhe M—C interaction energy. Four types of reaction are compared coke or carbide formation, hydrocarbon chain growth, CH4 formation, and CO dissociation. 

The following schematic representation of the relation between the hydrocarbons from methane to hexane may help to make clear the continually increasing number of isomers possible. 

Figure 1.6. Schematic representation of first-order configuration interaction for alternant hydrocarbons. Within the PPP approximation, conHgurations corresponding to electronic excitation from MO 4>i into and from MO., into are degenerate. The two highest occupied MOs (i =, k = 2) and the two lowest unoccupied MOs (f = r and k = 2 ) are shown. Depending on the magnitude of the interaction, the HOMO- LUMO transition

Figure 2.23a gives a schematic representation of the frontier orbital energy levels of an uncharged odd alternant hydrocarbon. It is seen that... 

Figure 2.23. Odd alternant hydrocarbon radicals a) Schematic representation of the frontier orbital energy levels and of the various configurations that are obtained by single excitations from the ground configuration o. (It should be remembered that spin eigenstates cannot be represented correctly in these diagrams.) b) Energies of these configurations and effect of first-order configuration interaction.

Figure 6.18a gives a schematic representation of the orbital correlation diagram fur the thermally forbidden conversion of one alternant hydrocarbon into another one. The following configuration correlations are easily verified from this diagram ... 

Figure 3.16 Schematic representation of amount of hydrocarbons generated in, and expelled from a type II kerogen-bearing source rock as a function of organic matter maturity for the initial part of the oil window (after Leythaeuser et al., 1987. Reprinted with permission from the Proceedings 12th World Petroleum Congress, Houston, Vol. 2, Fig. 2a, p. 229).

Fig. 8.10. Schematic representation of the dependence of the carbon nanostructure obtained by hydrocarbon pyrolysis on the size of the metal nanoparticles. Reproduced from ref [20a], with permission.

Fig. 8 is a schematic representation of a vacuum column, sometimes called a flasher, intended to produce asphaltene-free cracking feed and heavy black fuel oil. The fired preheat furnace is similar to the crude unit heater, except that tolerable tube skin temperatures are somewhat lower because of the absence of light hydrocarbons. 

Figure 2 Schematic representation of a spherical micelle and a section showing the disordered arrangement of the hydrocarbon chains...

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