Conversion isooctane

The two dimers of 2 methylpropene shown in the equation can be converted to 2 2 4 trimethylpentane (known by its common name isooctane) for use as a gasoline additive Can you suggest a method for this conversion ... 

The inhibition analyses were examined differently for free lipase in a batch and immobilised lipase in membrane reactor system. Figure 5.14 shows the kinetics plot for substrate inhibition of the free lipase in the batch system, where [5] is the concentration of (S)-ibuprofen ester in isooctane, and v0 is the initial reaction rate for (S)-ester conversion. The data for immobilised lipase are shown in Figure 5.15 that is, the kinetics plot for substrate inhibition for immobilised lipase in the EMR system. The Hanes-Woolf plots in both systems show similar trends for substrate inhibition. The graphical presentation of rate curves for immobilised lipase shows higher values compared with free enzymes. The value for the... 

A Chromobacterium viscosum lipase is microencapsulated in AOT reversed micelles in isooctane with a Wo=24 and used in the controlled hydrolysis of 50 mM triolein at pH 7.0 and 35°C, in a continous stirred membrane reactor, with a flow rate of 1 l.min 1 Design the reactor in order to achieve 95% of conversion. 

Figure 1. Percent conversion in isooctane cracking vs. cations content after (a) 550°C pretreatment, (6) 900°C pretreatment O isobutane, A isobutene. , A Nar8.7., A D.La-4 sample.

Enantioselective enzymatic transesterifications have been used as a complementary method to enantioselective enzymatic ester hydrolyses. The first example of this particular type of biotransformation is the synthesis of the optically active 2-acetoxy-l-silacyclohexane (5 )-78 (Scheme 19). This compound was obtained by an enantioselective transesterification of the racemic l-silacyclohexan-2-ol rac-43 with triacetin (acetate source) in isooctane, catalyzed by a crude lipase preparation from Candida cylindracea (CCL, E.C. 3.1.1.3)62. After terminating the reaction at 52% conversion (relative to total amount of substrate rac-43), the product (S)-78 was separated from the nonreacted substrate by column chromatography on silica gel and isolated in 92% yield (relative to total amount of converted rac-43) with an enantiomeric purity of 95% ee. The remaining l-silacyclohexan-2-ol (/ )-43 was obtained in 76% yield (relative to total amount of nonconverted rac-43) with an enantiomeric purity of 96% ee. Repeated recrystallization of (R)-43 led to an improvement of enantiomeric purity by up to >98% ee. Compound (R)-43 has already earlier been prepared by an enantioselective microbial reduction of the l-silacyclohexan-2-one 42 (see Scheme 8)53. The l-silacyclohexan-2-ol (R)-43 is the antipode of compound (.S j-43 which was obtained by a kinetic enzymatic resolution of the racemic 2-acetoxy-l-silacyclohexane rac-78 (see Scheme 15)62. For further enantioselective enzymatic transesterifications of racemic organosilicon substrates, with a carbon atom as the center of chirality, see References 64 and 70-72. 

A comparative study of nanocomposites (16% Nafion-silica and commercial SAC-13) has been performed by Hoelderich and co-workers169 in the alkylation of isobutane and Raffinate II. Raffinate II, the remaining C4 cut of a stream cracker effluent after removal of dienes, isobutane, propane, and propene, contains butane, isobutylene, and butenes as main components. High conversion with a selectivity of 62% to isooctane was found for Nafion SAC-13 (batch reactor, 80°C). Both the quality of the product and the activity of the catalysts, however, decrease rapidly due to isomerization and oligomerization. Treating under reflux, the deactivated catalysts in acetone followed by a further treatment with aqueous hydrogen peroxide (80°C, 2 h), however, restores the activity. 

Figure 2.86 Isooctane steam reformer performance. At constant residence time the hydrogen selectivity is not affecteded by decreasing the S/C ratio while the isooctane conversion is lowered [135] (by courtesy of S. P. Fitzgerald).

Wong et al. (14) also studied the effect of the amount of enzyme (lipase from Candida rugosa Sigma) on monocaprin synthesis in isooctane at 37°C. They observed that monocaprin molar fraction increased when the amount of lipase was increased, but no significant increase in monocaprin yield (conversion of capric acid equal to 35%) was observed for a lipase loading of more than 100.0 mg (corresponding to 16.4% [w/w]). 

At approximately the same reaction conditions, isooctane can be split, whereby isobutane is the main product. Similarly, a paraffinic oil boiling between 260° and 320°C. and decahydronaphthalene are converted almost completely into lower boiling hydrocarbons. Splitting of normal heptane, however, is slower. Even at 435°C. the conversion to... 

In some cases, substrates and enzymes are not soluble in the same solvent. To achieve efficient substrate conversion, a large interface between the immiscible fluids has to be established, by the formation of microemulsions or multiple-phase flow that can be conveniently obtained in microfluidic devices. Until now only a couple of examples are published in which a two-phase flow is used for biocatalysis. Goto and coworkers [431] were first to study an enzymatic reaction in a two-phase flow in a microfluidic device, in which the oxidation ofp-chlorophenol by the enzyme laccase (lignin peroxidase) was analyzed (Scheme 4.106). The surface-active enzyme was solubilized in a succinic acid aqueous buffer and the substrate (p-chlorophenol) was dissolved in isooctane. The transformation ofp-chlorophenol occurred mainly at... 

The global reactions considered include the conversion by pure pyrolysis of toluene to acetylene and the conversion of isooctane to ethylene, oxidative pyrolysis of the acetylene and ethylene, and partial oxidation of the parent fuels and these hydrocarbon intermediates to CO, H2, and H2O. The specific reactions and rates for this system are given in Table II. Soot formation is assumed to be a function of temperature and oxygen and precursor concentrations. In the present study the soot precursors are taken to be acetylene and toluene, expressed as C2 hydrocarbons. 

In this paper we report on factors which affect the conversion of fuel nitrogen to TFN in laboratory jet-stirred combustors which serve to simulate the primary zone in a gas turbine. The independent variables in the experiments were fuel type (aliphatic isooctane vs. aromatic toluene), equivalence ratio (fuel-to-oxygen ratio of combustor feed divided by stoichiometric fuel-to-oxygen ratio), average gas residence time in the combustor, and method of fuel injection into the combustor (prevaporized and premixed with air vs. direct liquid spray). Combustion temperature was kept constant at about 1900K in all experiments. Pyridine, C5,H5N, was added to the fuels to provide a fuel-nitrogen concentration of one percent by weight. 

Table I. Results from fuel nitrogen conversion experiments - isooctane fuel.

The pattern of increasing conversion for equivalence ratios richer than the hydrocarbon breakthrough equivalence ratio appeared to depend on the fuel, however. Figure 3 provides a comparison of fuel nitrogen conversion from isooctane and toluene at the richest equivalence ratios tested in the JSC. For both fuels, HC s increased as the equivalence ratio was increased from 1.6 to 1.8. Corresponding increases in fuel nitrogen conversion were found for isooctane mixtures at 3, 6 and 10 ms residence times, but toluene mixtures at these conditions produced either smaller increases or decreases in conversion with increasing... 

Figure 2. Conversion of isoprene after 2 hours at 60° C. in isooctane with catalyst systems based on (3-TiCk (5 mmole I liter) activated with increasing amounts of AlEh or AlEt2Cl cis-1,4 content of polymer produced with these catalysts.

Fig. 13.7 Normalized isooctane conversion as a function of time-on-stream for open circle) Ni/ YSZ and ( filled square) Sn/Ni/YSZ catalysts. The conversion is normalized with respect to the highest measured conversion for the Ni/YSZ catalyst. The Ni catalyst underwent major deactivation that led to pressure build-up in the reactor and complete destruction...

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