Reactor pipeline

Homogeneous reactions are those in which the reactants, products, and any catalysts used form one continuous phase (gaseous or liquid). Homogeneous gas phase reactors are almost always operated continuously, whereas liquid phase reactors may be batch or continuous. Tubular (pipeline) reactors arc normally used for homogeneous gas phase reactions (e.g., in the thermal cracking of petroleum of dichloroethane lo vinyl chloride). Both tubular and stirred tank reactors are used for homogeneous liquid phase reactions. 

Pipeline reactor for gaseous or liquid phase reactions Turbulent 1 or 2 six-element modules... 

Pipeline reactor to provide selectivity of product Laminar 10... 

The main advantage of this method compared with many other on-line methods for process monitoring is the use of noninvasive, so-called clamp-on sensors which can be easily mounted onto the process eqnip-ment (pipelines, reactors). The sensor, which often is a standard accelerometer, has no moving parts, and can, for example, withstand high temperatnres, a dirty enviromnent and is easy to maintain. The aconstic spectra measured with one sensor will often contain information abont several process-relevant properties and/or analytes which makes it possible to predict several parameters of interest from the same aconstic spectrum. 

Acoustic chemometrics has its greatest benefits in cases where haditional sensors and measurement techniques, such as flow, temperature and pressure transmitters cannot be used. In many processes it is preferable to use noninvasive sensors because invasive sensors may cause disturbances, for example fouling and clogging inside the process equipment such as pipelines, reactors cyclones, etc. In this chapter we concentrate mainly on new industrial applications for acoustic chemomehics, and only discuss the necessary elements of the more technical aspects of the enabling technology below - details can be found in the extensive background literature [3-5],... 

A second challenge was to rapidly develop real models as soon as possible after plant start-up, in spite of the relatively small variation in composition expected at a given process point. This challenge was solved by modelling all three process points (esterifier exit, pipeline reactor exit, and prepolymerizer exit) together. Inclusion of the process variability due to the start-up itself also helped. The calibration space for the first calibration set is shown in Figure 15.7. 

Figure 15.7 Calibration space covered by the first calibration set. The x-axis is lab carboxyl ends in meq/kg and the y-axis is DP in repeat units. The samples are labelled by process point 1 - esterifier, 2 - pipeline reactor and 3 - prepolymerizer. Reprinted with permission from Brearley and Hernandez (2000). ...

Rai, C. Microbial Desulfurization of Coals in a Slurry Pipeline Reactor Using Thiobacillus ferrooxidans. Biotechnology Progress 1, pp. 200-204, 1985. 

The ratio of the rms velocity fluctuation to the average velocity in the impeller zone is about 50% with many open impellers. If the rms velocity fluctuation is divided by the average velocity in the rest of the vessel, however, the ratio is on the order of 5-10%. This is also the level of rms velocity fluctuation to the mean velocity in pipeline flow. There are phenomena in microscale mixing that can occur in mixing tanks that do not occur in pipeline reactors. Whether this is good or bad depends upon the process requirements. 

Tubular Reactors In a tubular or pipeline reactor, gas and liquid flow concurrently A variety of flow patterns, ranging from a small quantity of bubbles in the liquid to small quantities of droplets in the gas, are possible, depending on the flow rate of the two streams. Figure 19-26/ shows the patterns in horizontal flow those in vertical flow are a little different. 

In recent years, the process has been modified to increase the yield of lower olefines, too. Continually improved since then, especially in the mid-1960s with the replacement of the original silica-alumina catalyst by a zeolite. The catalyst is now typically a zeolite Y, bound in a clay matrix. The feed is vaporized and contacted in a pipeline reactor with concurrently flowing microspheroidal catalyst particles. The catalyst is then separated from the hydrocarbon products and is continuously regenerated by burning off the coke in a fluidized bed. The process is licensed by UOP several hundred units are in operation worldwide. See also HS-FCC. 

Katz, S. 1960a. Best control actions in batch or pipeline reactors. Conference on Optimization Techniques in Chemical Engineering, New York University, May 18, 1960, pp. 57-78. 

Contactors in which gas is dispersed into the liquid phase Plate columns (including control cycle reactors) Mechanically agitated reactors (principally stirred tanks) Bubble columns Packed bubble columns Sectionalized bubble columns Two-phase horizontal contactors Cocurrent pipeline reactors Coiled reactors Plunging jet reactors, ejectors Vortex reactors... 

The reaction involves several intermediate, side and end products. For all these species, the concentration profiles in a pipeline reactor are obtained. The ozonation of NO is shown to be very fast and the importance of mixing of ozone is brought out. 

Sensitivity Analysis of Length-to-Diameter Ratio for the Pipeline Reactor... 

Let us continue with the case of L/D = 500, the same as that of the pipeline reactor with a diameter of 0.413 m. Considering the helix diameter to be 10 times the pipe diameter, D = 4.13 m. 

However, there is an enhancement in the heat transfer, too, compared to the pipeline reactor (Kern, 1950) ... 

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