Hydrocarbon reactions mixtures

The amount of acid in the acid-hydrocarbon reaction mixture also has an important bearing on the alkylate quality. If the reaction mixture contains less than 40% acid by volume, an acid-in-hydrocarbon emulsion results. Above this 40% inversion point, a hydrocarbon-in-acid emulsion is formed. The latter type produces the better product and consequently an acid volume of 60 to 70% of the reaction mixture is normally maintained. 

The results are presented as mole-fractions of reactants or products in the hydrocarbon reaction mixture, excluded nitrogen. Due to fest deactivation in our system, it was not possible to calculate the conversion, as this would require the knowledge of the exact coke amount at any time of the experiment. Nevertheless, as a measure of the conversion can be considered the quantity (1-yreactant). The higher the reactant mole-fraction, the lower is the conversion. 

Polymerizations are typically quenched with water, alcohol, or base. The resulting polymerizates are then distilled and steam and/or vacuum stripped to yield hard resin. Hydrocarbon resins may also be precipitated by the addition of the quenched reaction mixture to an excess of an appropriate poor solvent. As an example, aUphatic C-5 resins are readily precipitated in acetone, while a more polar solvent such as methanol is better suited for aromatic C-9 resins. 

Titanium carbide may also be made by the reaction at high temperature of titanium with carbon titanium tetrachloride with organic compounds such as methane, chloroform, or poly(vinyl chloride) titanium disulfide [12039-13-3] with carbon organotitanates with carbon precursor polymers (31) and titanium tetrachloride with hydrogen and carbon monoxide. Much of this work is directed toward the production of ultrafine (<1 jim) powders. The reaction of titanium tetrachloride with a hydrocarbon-hydrogen mixture at ca 1000°C is used for the chemical vapor deposition (CVD) of thin carbide films used in wear-resistant coatings. 

Dichloroethane is produced commercially from hydrogen chloride and vinyl chloride at 20—55°C ia the presence of an aluminum, ferric, or 2iac chloride catalyst (8,9). Selectivity is nearly stoichiometric to 1,1-dichloroethane. Small amounts of 1,1,3-tfichlorobutane may be produced. Unreacted vinyl chloride and HCl exit the top of the reactor, and can be recycled or sent to vent recovery systems. The reactor product contains the Lewis acid catalyst and must be separated before distillation. Spent catalyst may be removed from the reaction mixture by contacting with a hydrocarbon or paraffin oil, which precipitates the metal chloride catalyst iato the oil (10). Other iaert Hquids such as sdoxanes and perfluorohydrocarbons have also been used (11). 

The reaction is considerably modified if the so-called emulsion polymerisation technique is used. In this process the reaction mixture contains about 5% soap and a water-soluble initiator system. The monomer, water, initiator, soap and other ingredients are stirred in the reaction vessel. The monomer forms into droplets which are emulsified by some of the soap molecules. Excess soap aggregates into micelles, of about 100 molecules, in which the polar ends of the soap molecules are turned outwards towards the water whilst the non-polar hydrocarbon ends are turned inwards (Figure 2.17). 

In chemical laboratories, small flasks and beakers are used for liquid phase reactions. Here, a charge of reactants is added and brought to reaction temperature. The reaction may be held at this condition for a predetermined time before the product is discharged. This batch reactor is characterized by the varying extent of reaction and properties of the reaction mixture with time. In contrast to the flasks are large cylindrical tubes used in the petrochemical industry for the cracking of hydrocarbons. This process is continuous with reactants in the tubes and the products obtained from the exit. The extent of reaction and properties, such as composition and temperature, depend on the position along the tube and does not depend on the time. 

Figure 11.4-2 shows process flows for an HF alkylation unit. The three sections are 1) reaction, 2). settling and 3) fractionation. In the reaction section isobutane feed is mixed with the olefin feed (usually propylene and butylene) in approximately a 10 or 15 to 1 ratio. In the presence of the HF acid catalyst the olefins react to form alkylate for gasoline blending. The exothermic reaction requires water cooling. The hydrocarbon/HF mixture goes to the settling... 

The latter compound can be isolated from the reaction mixture by chromatography on acid-washed alumina. Similar treatment of the trans-ketone (117a) followed by isolation and chromatography on alumina gives the same equilibrium mixture. The structure of the thermodynamically more stable ketone (116a) was proved by its conversion by Wolff-Kishner reduction to the hydrocarbon (118) independently synthesized from the known... 

If r[, the rate of reaction 1, is extremely high, then the secondary reaction of the substrate E with the hydrocarbon organometallic does not take place The temperature at which the reaction mixture is subsequently terminated by hydrolysis IS also an important factor... 

Nitrosyl chloride reacts with aliphatic hydrocarbons at room temperature under the influence of light to give a complex mixture of substitution products. When the reaction is run on cyclohexane at —25°, however, the pure oxime hydrochloride crystallizes from the reaction mixture with virtually no side products. 

An antipolymerization agent such as hydroquinone may be added to the reaction mixture to inhibit the polymerization of the maleate or fumarate compound under the reaction conditions. This reaction is preferably carried out at a temperature within the range of 20°C to 150°C. This reaction is preferably carried out at atmospheric pressure. Reaction time of 16 to 24 hours have bean specified for this reaction by J.T. Cassaday. The reaction is preferably carried out in a solvent such as the low molecular weight aliphatic monohydric alcohols, ketones, aliphatic esters, aromatic hydrocarbons or trialkyl phosphates. 

In all experiments, unless otherwise stated, approximately 5% oxygen was added to the reaction mixture to remove free radicals from the system and thereby simplify the derivation of the modes of formation of the hydrocarbon products. 

Hoijtink and co-workers (13) found that with some hydrocarbons, a concentration of radical cations can be enhanced by the uv irradiation of the reaction mixture, under which a fission of the addition complex to the radical cation occurs. Further progress in preventing reaction (2) could be achieved by sterically hindered oxidizing agents. 

The distinguishing feature of the salt [28 2 ] is most evident in THF. As shown in Fig. 7, the anion [2 ] reacts rapidly with the cation [28 ]. However, the concomitant formation of the radical [2-] in smaller amount than the consumed anion is observed spectrophotometrically. The difference between the amounts of consumed [2 ] and of produced [2-] is attributed to the formation of the covalent hydrocarbon [28-2] in THF solution. Furthermore, the dimer [28-28] of 1,3,5-tricyclopropyltropyl radical [28-] is isolated in 20% yield from the reaction mixture after 48 h at room temperature. 

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