Conversion profiles

Once fundamental data have been obtained, the goal is to develop a mathematical model of the process and to utilize it to explore such possibilities as produc t selectivity, start-up and shut-down behavior, vessel configuration, temperature, pressure, and conversion profiles, and so on. 

Figure 6-6. Temperature versus fractional conversion profiles for various rates of heat input in a batch reactor.

Omoleye, J. A., Adesina, A. A., and Udegbunam, E. O., Optimal design of nonisothermal reactors Derivation of equations for the rate-temperature conversion profile and the optimum temperature progression for a general class of reversible reactions, Chem. Eng. Comm., Vol. 79, pp. 95-107, 1989. 

The styrene conversion versus reaction time results for runs in the laminar flow regime are plotted in Figure 8. Both the rate of polymerization and the styrene conversion increase with increasing flow rate as noted previously (7). The conversion profile for the batch experimental run (B-3) is presented as a dashed line for comparison. It can be seen that the polymerization rates for runs with (Nj e e 2850 are greater than the corresponding batch polymerization with a conversion plateau being reached after about thirty minutes of reaction. This behavior is similar to the results obtained in a closed loop tubular reactor (7J) and is probably due to an excessively rapid consumption of initiator in a... 

Part cures were characterized by exothermic reaction wave propagation. Figures 6a-9b show the development of the reaction waves. The waves propagate from the walls of the part towards the center. A comparison of the temperature and epoxide conversion profiles revealed that the highest temperature corresponded to the highest conversion. As the part initially heats the resin/glass matrix nearest the walls heats fastest however, as the part exotherms the temperatures in the interior of the part exceeded the wall temperatures. The center temperature does not become the hottest temperature until the waves intersect. It must be noted that the hottest temperature does not always occur at the center of the part. The wave velocities are proportional to the wall temperatures. In Figures 6a to 9b the mold temperature was 90 C and the press temperature was elevated to 115 C. Since the press does not heat the part until after it is wound, the press temperature was elevated to accelerate the reaction wave from the press so that the waves would intersect in the center of the part. 

VHiereas the previous case revealed temperature and conversion profiles propagating with almost constant velocity ("constant-pattern profiles"), the next case shows oscillatory behavior of the filtration combustion process for parameters a = 1.0, p = 0.08, y = 0.05, 6 = 1.0, (A) = 100.0, L =50.0 and 8 = -10.0. Figure 3a... 

Fig. 1. Conversion profiles under the operation conditions of original and enhanced productivity.

This is a further deepened work of what Samsung Total accomplished[12-14] several years ago. Several operation conditions including hardware modification which may enhance the productivity were deduced and simulated using the simulation model. Some ideas wctb alre y applied to commercial plant when they were concluded practically reasonable while some are on the waiting list One of the examples of productivity enhancement is shown in Fig. 1 and Fig. 2 which compare the conversion profiles and MWDs under original and revised operation conditions. As shown in these two figures the productivity was mhanced while MWD docs not change much. 

Figure 5.78. The influence of jacket temperature (TJ = 600, 620, 640, 660) is seen in these steady-state conversion profiles.

Temperature and Conversion Profiles for Packed Bed Reactor Network... 

Fig.8 Temperature and conversion profiles recorded by RTIR spectroscopy upon UV exposure of a PUA film (Iq =11 mW cm-2)...

Rewrite equation 15.2-1 as a differential equation representing the gradient of fA with respect to position (x) in a PFR, dfA/dx. (Integration of this form gives the conversion profile.)... 

Fig. 39. H202 conversion profiles (a) for reaction catalyzed by Ti-SBA-15 (sample 1, 30 mg) and (b) by Ti-MMM (33 mg). Reaction conditions H202, 1.29 mmol Ti, 0.013 mmol MeCN, 3 ml T = 353 K [from Trukhan et al. (234)].

A second order gas phase reaction, 2A + B => C, is done in a furnace with ambient temperature 1600 R. Inlet temperature is 1500 F, the pressure is 5 atm. The feed is 20 lbmol/hr, consisting of 40% each of A and B and 20% inerts. Given the data following, find temperature and conversion profiles when (a) the heat transfer coefficient is 1) 10 Btu/(hr) (cuft) (R) (b) the... 

Time-Conversion Profile of a Surface Photografting System,... 

In the present discussions, we neglect the effects of homo-polymer formation. HomopolyAM deposited on OPP surface in the course of grafting may prevent diffusion of AM to the grafting site, which may slow down the rate of grafting. It is however difficult to explain by this reasoning the change in time-conversion profile as a function of [AM]/[BP] ratio. Since our aim is surface modification, the amount of homopolymer was not determined. ... 

In this section we develop a scheme implemented in a continuous polymerization reactor to regulate polydispersity by tracking periodic conversion profiles and maintaining stable temperature conditions. Oscillatory conversion is tracked by manipulating the initiator feedrate while the heat exchange rate is used to regulate reactor temperature. 

In this manner the temperature and conversion profiles are found. The result is shown in Fig. E9.4c. 

Results of a study of the ozonolysis of primary combustion aerosols by Van Vaeck and Van Cauwen-berghe (1984a) are illustrated in Fig. 10.30. Shown are percent conversion profiles as a function of time for the decay of several 5- and 6-ring PAHs in diesel exhaust... 

The program was designed so as to start with a fixed feed rate of the reactant A at time zero. Temperature and conversion profiles along the length of the reactor tube were calculated and displayed on the oscilloscope output of the computer. If temperature exceeded a limiting value, the feed rate was automatically reduced and a new profile determined. As soon as a satisfactory profile was determined at the initial conditions, the time was increased by a predetermined increment and the calculation continued. 

Figure 17.34. Temperature and conversion profiles in a water-cooled shell-and-tube phosgene reactor, 2-in. tubes loaded with carbon catalyst, equimolal CO and Cl2.

Figure 17.35. Temperature and conversion profiles of mild thermal cracking of a heavy oil in a tubular furnace with a back pressure of 250 pag and at several heat fluxes [Btu/hr(sqft)].

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