Reactors fractionating

Yield-Based Reactor Fractional Conversion Reactor Combined Specification Model Well-Stirred Reactor Model Plug Flow Reactor Model Two Phase Chemical Equilibrium General Phase and Chemical Equilibrium... 

Figure 3.35 Presentation page of a block-oriented simulator for the analysis of a coupled FCC reactor-fractionator (Hysim 1995).

Figure 7. Propane pyrolysis in Type II reactor. Fraction unconverted corrected to plug flow vs. value calculated by Equation 8 (Xp vs. XcaIJ.

In the case of a single reaction carried out in a reactor, fractional conversion of the limiting reactant (xy ) achieved in the reactor is usually taken as the index of reactor performance. In the case of multiple reactions, as conversion of limiting reactant leads to the formation of multiple products, conversion alone cannot be taken as an indication of good performance. Performance is considered to be good if conversion of a certain quantity of reactant leads to the formation of a larger proportion of desired product and a relatively lower proportion of undesired product. Thus, for multiple reactions, performance is characterised by two more factors apart from conversion, namely, yield and selectivity. Overall yield y is defined as the fraction of the overall limiting reactant that is converted into the desired product. Overall selectivity O is defined as the ratio of the amount of desired product to the amount of undesired product produced. If B is the desired product and C is the undesired product of the series reaction A— then for any batch time t... 

Type 316 is usually used for reactors, fractionating columns, traps, baffles, caps and piping. 

Quarter of reactor Fractional conversion of A leaving quarter Fraction of total heat removed in quarter... 

Our HP HCR model includes three major parts of the commercial HCR process reactors, fractionators, and hydrogen recycle system. In the reactor model, we define the inlet temperature of each catalyst bed, and the model will calculate the outlet temperature of each bed. The AADs of catalyst bed outlet temperatures of the two HCR reactors are 1.8 °C and 3.2 °C for series 1 and series 2, respectively. Figures 6.49 to 6.50 show the model predictions of WARTs of HT reactors and HCR reactors. The model generates good predictions on the temperature profile of reactors. Figure 6.51 represents the modeling result of the makeup hydrogen flow rate, and the ARD is only 2%. 

We develop two integrated HCR process models which include reactors, fractionators and hydrogen recycle systems. 

Laboratory studies indicate that a hydrogen-toluene ratio of 5 at the reactor inlet is required to prevent excessive coke formation in the reactor. Even with a large excess of hydrogen, the toluene cannot be forced to complete conversion. The laboratory studies indicate that the selectivity (i.e., fraction of toluene reacted which is converted to benzene) is related to the conversion (i.e., fraction of toluene fed which is reacted) according to ... 

Given the assumptions, estimate the composition of the reactor effluent for fraction of methane in the recycle and purge of 0.4. 

Figure 4.9 shows a plot of Eq. (4.12). As the purge fraction a is increased, the flow rate of purge increases, but the concentration of methane in the purge and recycle decreases. This variation (along with reactor conversion) is an important degree of freedom in the optimization of reaction and separation systems, as we shall see later. 

Given the estimate of the reactor effluent in Example 4.2 for fraction of methane in the purge of 0.4, calculate the.actual separation in the phase split assuming a temperature in the phase separator of 40°C. Phase equilibrium for this mixture can be represented by the Soave-Redlich-Kwong equation of state. Many computer programs are available commercially to carry out such calculations. 

Clearly, the time chart shown in Fig. 4.14 indicates that individual items of equipment have a poor utilization i.e., they are in use for only a small fraction of the batch cycle time. To improve the equipment utilization, overlap batches as shown in the time-event chart in Fig. 4.15. Here, more than one batch, at difierent processing stages, resides in the process at any given time. Clearly, it is not possible to recycle directly from the separators to the reactor, since the reactor is fed at a time different from that at which the separation is carried out. A storage tank is needed to hold the recycle material. This material is then used to provide part of the feed for the next batch. The final flowsheet for batch operation is shown in Fig. 4.16. Equipment utilization might be improved further by various methods which are considered in Chap. 8 when economic tradeoffs are discussed. 

One of the most significant sources of change in isotope ratios is caused by the small mass differences between isotopes and their effects on the physical properties of elements and compounds. For example, ordinary water (mostly Ej O) has a lower density, lower boiling point, and higher vapor pressure than does heavy water (mostly H2 0). Other major changes can occur through exchange processes. Such physical and kinetic differences lead to natural local fractionation of isotopes. Artificial fractionation (enrichment or depletion) of uranium isotopes is the basis for construction of atomic bombs, nuclear power reactors, and depleted uranium weapons. 

Fig. 9. Xylenes separation via Mitsubishi Gas—Chemical Co. HF-BF extraction—isomerization process (107). A = extractor B = decomposer C = separator D = isomerization reactor E = heavy ends tower F = raffinate tower G = separator H = light ends fractionator ...

The mixture is cooled and noncondensable gases are scmbbed with water. Some of the resultant gas stream, mainly hydrogen, may be recycled to control catalyst fouhng. The Hquids are fractionally distilled, taking acetone overhead and a mixture of isopropyl alcohol and water as bottoms. A caustic treatment maybe used to remove minor aldehyde contaminants prior to this distillation (29). In another fractionating column, the aqueous isopropyl alcohol is concentrated to about 88% for recycle to the reactor. 

The alcoholysis reaction may be carried out either batchwise or continuously by treating the triglyceride with an excess of methanol for 30—60 min in a well-agitated reactor. The reactants are then allowed to settle and the glycerol [56-81-5] is recovered in methanol solution in the lower layer. The sodium methoxide and excess methanol are removed from the methyl ester, which then maybe fed directiy to the hydrogenolysis process. Alternatively, the ester may be distilled to remove unreacted material and other impurities, or fractionated into different cuts. Practionation of either the methyl ester or of the product following hydrogenolysis provides alcohols that have narrow carbon-chain distributions. 

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