Product distribution for

Propane. The VPO of propane [74-98-6] is the classic case (66,89,131—137). The low temperature oxidation (beginning at ca 300°C) readily produces oxygenated products. A prominent NTC region is encountered on raising the temperature (see Fig. 4) and cool flames and oscillations are extensively reported as compHcated functions of composition, pressure, and temperature (see Fig. 6) (96,128,138—140). There can be a marked induction period. Product distributions for propane oxidation are given in Table 1. 

Exxon was the first to investigate the suitabiUty of a wide range of different U.S. coals for conversion. Operation of the EDS process was demonstrated in a 230 t/d unit in Baytown, Texas that had a start-up in May of 1980. Data on the response of a variety of coals to once-through and bottoms recycle operations are shown in Eigure 4. Eigure 5 presents typical Hquefaction product distributions for the system operated both with and without the Elexicoking (fluidized-bed coking) option. 

Table 4. Product Distribution for the Occidental Flash Pyrolysis Process...

Table 5. Selectivities and Product Distributions for Fixed- and Fluidized-Bed Units at SASOL I...

SASOLII a.ndIII. Two additional plants weie built and aie in operation in South Africa near Secunda. The combined annual coal consumption for SASOL II, commissioned in 1980, and SASOL III, in 1983, is 25 x 10 t, and these plants together produce approximately 1.3 x lO" m (80,000 barrels) per day of transportation fuels. A block flow diagram for these processes is shown in Figure 15. The product distribution for SASOL II and III is much narrower in comparison to SASOL I. The later plants use only fluid-bed reactor technology, and extensive use of secondary catalytic processing of intermediates (alkylation, polymerisation, etc) is practiced to maximise the production of transportation fuels. 

Product Distribution. In addition to ethylene, many by-products are also formed. Typical product distributions for various feeds from a typical short residence time furnace are shown in Table 5. The product distribution is strongly influenced by residence time, hydrocarbon partial pressure, steam-to-od ratio, and coil outlet pressure. 

In other work, these authors examined the product distribution for Eq. (2.3) as a function of ring size formed. Maximum yields for cyclic product were observed when a five-oxygen, seventeen-membered ring was formed. 

Methane is the most difficult alkane to chlorinate. The reaction is initiated by chlorine free radicals obtained via the application of heat (thermal) or light (hv). Thermal chlorination (more widely used industrially) occurs at approximately 350-370°C and atmospheric pressure. A typical product distribution for a CH4/CI2 feed ratio of 1.7 is mono- (58.7%), di-(29.3%) tri- (9.7%) and tetra- (2.3%) chloromethanes. 

TABLE 2. Product distribution for the displacement reaction of allyl sulfones 9 with lithium dialkyl cuprates6... 

DePuy, C.H. King, R.W. Chem. Rev., 1960, 60, 431, have tables showing the product distribution for many cases. 

The FCC process is used worldwide in more than 300 installations, of which about 175 are in North America and 70 in Europe. Figure 9.10 shows the principle of an FCC unit. The preheated heavy feed (flash distillate and residue) is injected at the bottom of the riser reactor and mixed with the catalyst, which comes from the regeneration section. Table 9.5 gives a typical product distribution for the FCC process. Cracking occurs in the entrained-flow riser reactor, where hydrocarbons and catalyst have a typical residence time of a few seconds only. This, however, is long enough for the catalyst to become entirely covered by coke. While the products leave the reactor at the top, the catalyst flows into the regeneration section, where the coke is burned off in air at 1000 K. 

Typical Mossbauer spectra for the fresh, reduced, carblded and used Fe/ZSM-5 system are shown in a composite Fig. 5. Similar spectra were obtained for the Fe-Co/ZSM-5 system. The product distribution for the F-T reaction, using the Fe and Fe-Co systems, are shown in Table 1. The gasoline range hydrocarbon yield increased from 75 to 94%, when the Fe-Co clusters were used in place of Fe only. In a typical CEMS (Conversion Electron Mossbauer Spectroscopy) of the Fe-Co system, no spectrum for 57pg vas observed even after one week from this. It was concluded that in the Fe-Co clusters Co was predominantly in the "mantle" and Fe species were In their "core," in the parlance of metallurgy/geophysics. This model Is sometimes referred to as the cherry model. 

When the same [NiI (NHC)2] complexes are employed as alkene dimerisation catalysts in ionic liquid (IL) solvent [l-butyl-3-methylimidazolium chloride, AICI3, A-methylpyrrole (0.45 0.55 0.1)] rather than toluene, the catalysts were found to be highly active, with no evidence of decomposition. Furthermore, product distributions for each of the catalyst systems studied was surprisingly similar, indicating a common active species may have been formed in each case. It was proposed that reductive elimination of the NHC-Ni did indeed occur, as outlined in Scheme 13.8, however, the IL solvent oxidatively adds to the Ni(0) thus formed to yield a new Ni-NHC complex, 15, stabilised by the IL solvent, and able to effectively catalyse the dimerisation process (Scheme 13.9) [25-27],... 

TABLE 6.1 Product Distributions for the Reactions of Alkyl-Substituted Phenoxides with p-Carboxybenzyl Chloride in Water at 25°C... 

Product distribution For many years high pressure hydrogenation reaction has been dealt with as a consecutive reaction with asphaltene as the intermediate (4,5,6). Further it has been pointed out that Py-1, O2 likewise shows the behavior of intermediates. (See Figure 1) (3). 

The first step in the determination of the product distribution for reactions 9.3.3 and 9.3.4 is an evaluation of the instantaneous yield. 

It is possible to represent the product distributions for both the batch and CSTR cases in the form of time independent plots, as shown in Figures 9.9 and 9.10. The plots are prepared using equations 9.3.9 (or 9.3.10), 9.3.11, 9.3.12, and 9.3.16. As the reaction proceeds, B is consumed, and one moves from left to right along the curve representing the appropriate value of k2/kx. The dashed lines of slope 2 on the figures indicate the amount of B consumed to reach a particular point on the curve being followed. This value of... 

If the two competing reactions have the same concentration dependence, then the catalyst pore structure does not influence the selectivity because at each point within the pore structure the two reactions will proceed at the same relative rate, independent of the reactant concentration. However, if the two competing reactions differ in the concentration dependence of their rate expressions, the pore structure may have a significant effect on the product distribution. For example, if V is formed by a first-order reaction and IF by a second-order reaction, the observed yield of V will increase as the catalyst effectiveness factor decreases. At low effectiveness factors there will be a significant gradient in the reactant concentration as one moves radially inward. The lower reactant concentration within the pore structure would then... 

Product distribution for propane pyrolysis. [From Schutt, Chemical Engineering Progress, 50 (415), 1954. Used with permission.]... 

Table III. Relative Product Distributions for the Reactions of Co+ and Ni+ with Alkanes a...

Table IV. Product Distribution for Exothermic Reactions of Co+ with C5H10 Isomers...

More than just a few parameters have to be considered when modelling chemical reactivity in a broader perspective than for the well-defined but restricted reaction sets of the preceding section. Here, however, not enough statistically well-balanced, quantitative, experimental data are available to allow multilinear regression analysis (MLRA). An additional complicating factor derives from comparison of various reactions, where data of quite different types are encountered. For example, how can product distributions for electrophilic aromatic substitutions be compared with acidity constants of aliphatic carboxylic acids And on the side of the parameters how can the influence on chemical reactivity of both bond dissociation energies and bond polarities be simultaneously handled when only limited data are available ... 

The description of the product distribution for an FT reaction can be simplified and described by the use of a single parameter (a value) determined from the Anderson-Schulz-Flory (ASF) plots. The a value (also called the chain growth probability factor) is then used to describe the total product spectrum in terms of carbon number weight fractions during the FT synthesis. In the case... 

One way to get a representative product distribution for a specific period is to remove all FT products in the reactor system and replace them with a substance that will not influence selectivity determination. The FT reaction is then run for a specific period, after which a full analysis can be done that will represent only the products produced during that specific period. In Figure 13.8, data are presented for a run started with the catalyst suspended in a highly paraffinic wax (FT HI wax, C30-C90). After a certain time of synthesis, the FT run was stopped and the catalyst placed under inert conditions (argon). The reactor content was then displaced with degassed and dried polyalphaolefin oil (Durasyn). After restarting the FT synthesis, the total product spectrum was determined (HI run after displacement). It was found that the value of a2 was much lower than before the displacement of the HI wax. In fact, the a2 values were quite comparable to those measured when the FT synthesis was started up with Durasyn (compare with Durasyn runs 1, 2, and 3). This clearly illustrates the impact that the reactor medium used to start the FT reaction can have on the determination of the a-value. The results further show that there was no change in the value of a2 of the iron catalyst up to 500 h on-line. 

Table 8 Product distribution for the methylation of 1,2,3-thiadiazoles with Meerwein s reagent...

Assuming that the allyl Cl and C3 centers have an intrinsic reactivity, which is independent of the direct coupling partner (Cl or C3 of the second allyl radical), the results of a variety of different experimental investigations can be examined comparatively. If this assumption holds true, the relative product distribution for an allyl radical with intrinsic reactivity of A at Cl and of B at C3 should be given by equation 21. 

Table 1. Experimental Product Distributions for the Decomposition of Various...

These rate laws are coupled through the concentrations. When combined with the material-balance equations in the context of a particular reactor, they lead to uncoupled equations for calculating the product distribution. For a constant-density system in a CSTR operated at steady-state, they lead to algebraic equations, and in a BR or a PFR at steady-state, to simultaneous nonlinear ordinary differential equations. We demonstrate here the results for the CSTR case. 

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