Comparison with conventional reactor

For highly exothermic reactions the so-called HEX reactors present a very promising option. The basic common feature of all HEX reactors is much more favorable heat transfer conditions in comparison with conventional reactors (heat transfer coefficients typically 3500-7500 W/m2K, heat transfer areas up to 2200 m2/m3). A HEX reactor developed by BHR Group Ltd. (Figure 14) was able to decrease the by-product formation in one of ICI Acrylics processes by 75% (41) and to decrease the processing time in a Hickson Welch fine chemical process from 18 hours to 15 minutes, saving 98.6% of batch time (42). 

Gogate PR, Mujumdar S, Thampi J, Wilhelm AM, Pandit AB (2004) Destruction of phenol using sonochemical reactors scale up aspects and comparison of novel configuration with conventional reactors. Sep Purif Technol 34 25-34... 

Fig. 22 Static mixer reactor for two-phase process Comparison with conventional stirred tank...

Figure 2 shows the comparison of the conversion of COj into C with conventional reactor with that of membrane reactor. It is clearly shown that the conversion into C drastically increased with the apphcation of membrane reactor to CH4 decomposition. Although the conversion into C was as low as 10% at 500°C in the conventional fixed bed reactor, it attained 72% on the membrane reactor. The conversion into C was further increased with increasing the flow rate of sweep Ar, since the permeation rate of Hj was increased. Figure 3 shows the effects of flow rate of sweep Ar of membrane reactor system on the catalytic reduction of COj. Although the conversion of CO2 was independent on the flow rate of sweep Ar and attained a value as high as 32% at 400°C, which is available temperature for CO2 fixation in a practical apphcation. 

Fig. 2 Comparison of the conversion of CO2 into carbon with conventional reactor with that of membrane reactor. Temperature at CO2 methanation was fixed at 300°C. closed symbol membrane reactor open symbol conventional fixed bed reactor...

In discussing microreaction systems, it is helpful to first distinguish the characteristic size of a microreactor in comparison with conventional scale reactors. Two different definitions of the term microreactor are commonly used in the literature. The first defines any reactor that is an order of magnitude or more smaller than its conventional scale coimterpart as a microreactor. For example, an industrial reforming reactor might be 10,000-100,000 L in volume. Using this first definition, a 1 L reforming reactor could be considered a microreactor. This definition is not very useful as it... 

Agreement of data from the wall-less reactor with conventional reactors is excellent when valid comparisons can be made. Neopentane which exhibits significant surface effects has the same kinetic constants (within experimental error) when pyrolyzed either in the wall-less(K ) or shock tube reactor(T ). Oxygen-free ethane exhibits only a very small surface effect(8). and there is excellent agreement between the wall-less and conventional static reactors as is noted in this paper. 

Example 14.3.6. A Simulation of a Bubble Column Reactor Considering Detailed Flow Patterns and a First-Order Irreversible Reaction. Comparison with Conventional Design Models... 

SIMULATION OF A BUBBLE COLUMN REACTOR CONSIDERING DETAILED FLOW PATTERNS AND A FIRST-ORDER IRREVERSIBLE REACTION. COMPARISON WITH CONVENTIONAL DESIGN MODELS... 

Demoulin, O., Navez, M., Gracia, F., et al. (2004). High throughput experimentation applied to the combustion of methane and a comparison with conventional micro-reactor measurements, Catal Today, 91-92, pp. 85-89. 

In a series of controlled experiments, Dosi et al. used the conversion of glucose to lactic acid as a model for the potential of controlling (automatically by computer) the concentrations of the constituents.45 Nice schematics for the reactor setup and connections to the computer/NIR spectrometer/microhltration unit, etc., are shown. Six cases are described, each using a conventional batch process. Transition from batch mode to automatic was triggered by predefined criteria such as degree of substrate conversion or biomass concentration. Control charts and comparisons of NIR data with conventional assays are given for all six cases. 

Conventional reactor designs have been optimized to create a basis for comparison. The mechanically agitated vessel achieves the highest yield of 74.4%, followed by the bubble column reactor with a yield of 72.9%, and the co-as well as the countercurrent reactors both achieving a yield of 69.5%. 

Economic comparisons of conventional technologies with micro reactors have also been discussed [37]. An exemplary comparison for an investment decision in a chemical development pilot unit is given in Table 4.5. In this calculation a micro reactor array is used in place of a 501 batch vessel in a pilot-plant environment... 

In order to interpret and further analyze the results obtained for the membrane reactor it is expedient to perform a comparison with the conventional fixed-bed reactor. Following studies conducted by Reo et al. [49, 50], the three possible configurations illustrated in Fig. 12.11 could be compared. 

Comparison of the Performance of a Reciprocating Reactor with That of a Conventional Reactor ... 

Typical results obtained in a laboratory reactor, 4.8 mm i.d. and 18.3 m in height, show that more than 84% yield of acrylonitrile is obtained. In comparison with that of the conventional fluidized bed reactor, the yield is improved by about 9%. 

When the values shown in Table 2 are used to calculate the overall molar production rates per unit volume of reactor for monolith reactors, values of 40 mol/mreactor s are foimd. Figure 14 illustrates that this value is very high in comparison with those foimd in conventional catalytic reactors used in industry. 

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