Assisted Reaction Engineering

The author wishes to thank for substantial contributions and excellent cooperation Dr. A. Tuchlenski, Dr. O. Schramm, Dr. S. Thomas, Dr. F. Klose, Dr. T. Wolff, C. Hamel, M. Joshi, and A. Tota. The numerous discussions with Prof. J. Caro, Dr. R. Dittmeyer and with colleagues in the project Membrane assisted reaction engineering , were also extremely enjoyable and helpful. Finally, the financial support of Deutsche Forschungsgemeinschaft, German Ministry of Education and Research, Max-Buchner-Forschungsstiftung and Fonds der Chemischen Industrie is gratefully acknowledged. 

Electroogranic synthesis engineering Sonoorganic synthesis engineering Microphase-assisted reaction engineering... 

Membrane-assisted reaction engineering Multifunctional reactor engineering... 

R. Bierbaum M. NUchter B. Ondruschka. Microwave-Assisted Reaction Engineering Miniplant-Scale Microwave Equipment with On-Line Analysis. Chemie Inge-nieur Technik. 76, 961-965, 2004. 

Despite the often large increase in the reaction rate the use of microwave-assisted reactions has still not been implemented on an industrial scale. One of the main barriers for industrial applications is reliable scale-up of microwave reactors [116], but there are also other engineering problems that have to be solved. The use of microwaves to speed-up distillation processes has also been indicated [123]. 

The question of reproducibility and scale-up will always imply the question about reaction conditions. In addition, the reaction medium (phase) plays a much more important role for this kind of power input compared with classical reactions. Besides the molecular mass, reaction mixture polarity is essential for absorption of microwave power. Because dielectric constants are known for a few compounds only and, moreover, at near room temperature, more problems are predictable and require dose contact with neighboring disciplines, for example with electrical engineering. The primary literature reflects the incomplete nature of results from microwave-assisted reactions and processes, as it does for conventional syntheses. The dependence of reaction engineering on technical considerations is, however, greater for microwave-assisted reactions, so improved description of reaction conditions is crucial. 

The combination of NOx trapping materials with NH3-SCR catalysts for the NOx treatment from mobile lean-burn engines has been reported. Particular attention has been paid in the mechanism of ammonia emission and reactivity toward NOx abatement in NSR process. For the first point, two reaction paths are proposed in the literature. In the presence of hydrogen during the rich pulses of the LNT regeneration, ammonia can be formed by direct reaction with the previously stored NOx. When CO is use as the reductant agent, water-assisted reaction, by hydrolysis of intermediate isocyanate species, is suggested. In the presence of water and carbon dioxide in the gas mixture, both reaction pathways co-exist due to direct and reverse water gas shift reaction. Ammonia is thereafter involved in the NOx reduction mechanism, by a sequential route in which NH3 reacts faster with NOx to yield N2 compared with its own formation rate. It is found that both the nature and the content of the basic element as well as the redox properties of the support interfere in NH3 yield. 

Part III Beyond the Fundamentals presents material not commonly covered in textbooks, addressing aspects of reactors involving more than one phase. It discusses solid catalyzed fluid-phase reactions in fixed-bed and fluidized-bed reactors, gas-solid noncatalytic reactions, reactions involving at least one liquid phase (gas-liquid and liquid-liquid), and multiphase reactions. This section also describes membrane-assisted reactor engineering, combo reactors, homogeneous catalysis, and phase-transfer catalysis. The final chapter provides a perspective on future trends in reaction engineering. 

CARM is a software package developed by Prof. J.-Y. Chen of UC, Berkeley, that automatically creates reduced chemical kinetic mechanisms starting with a detailed mechanism and a set of input problems representing the conditions under which the mechanism is to be used (Reaction-Engineering-Intemational 2014). CARM is an acronym of Computer Assisted Reduction Method . The output of CARM is a Fortran subroutine that gives the chemical source terms for each species in the reduced mechanism as a function of the temperature, pressure and species mass fractions. This subroutine can be used in a CFD code or in simpler applications such as those associated with the CHEMKIN package. Application of CARM was reported by Sung et al. (2001). 

Reaction-Engineering-Intemational CARM (Computer Assisted Reduction Method), http // energy.reaction-eng.com/modeling tools/carm.html (2014)... 

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