Microreactor industry

Kashid, M. N., Gerlach, 1., Goetz, S., Franzke, J., Acker, J., Platte, F., et al. (2005). Internal circulation within the liquid slugs of a liquid-liquid slug-flow capillary microreactor. Industrial... 

Alfadhel, K. and Kothare, M.V. (2005) Modeling of multicomponent concentration profiles in membrane microreactors. Industrial Engineering Chemistry Research, 44 (26), 9794-9804. 

Y. Wada, M. A. Schmidt, K. F. Jensen, Flow distribution and ozonolysis in gas-bquid multichannel microreactors. Industrial and Engineering Chemistry Research, 2006, 45, 8036-8042. 

Microreactors find new niches, Achema Daily/Chemical Engineering, June 1997 Conclusions on IMRETl micro-reactor exhibitors at ACHEMA 1997 expert opinions industry s commitment general advantages of micro flow views on commercialization extended list of leading institutes and companies activities topological approach numbering-up [226],... 

V., Microreactors, Ullmann s Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim (1999). 

Jackel, K. P., Microtechnology Application opportunities in the chemical industry, in Ehreeld, W. (Ed.), Microsystem Technology for Chemical and Biological Microreactors, DECHEMA Monographs,... 

Jahnisch, K., Ehrich, H., Linke, D., Baerns, M., Hessel, V, Morgen-scHWEis, K., Selective gas/liquid-reactions in microreactors, in Proceedings of tfie Inten. Conference on Process Intensification for tfie Cfiemical Industry (13-15 October 2002), Maastricht, The Netherlands. 

WoRZ, O., Jacket, K. P., Richter, T, Wole, A., Microreactors, new efficient tools for optimum reactor design. Microtechnologies and Miniaturization, Tools, Techniques and Novel Applications for the BioPharmaceutical Industry, IBC Global Conferences, London (1998). 

Quite new ideas for the reactor design of aqueous multiphase fluid/fluid reactions have been reported by researchers from Oxeno. In packed tubular reactors and under unconventional reaction conditions they observed very high space-time yields which increased the rate compared with conventional operation by a factor of 10 due to a combination of mass transfer area and kinetics [29]. Thus the old question of aqueous-biphase hydroformylation "Where does the reaction takes place " - i.e., at the interphase or the bulk of the liquid phase [23,56h] - is again questionable, at least under the conditions (packed tubular reactors, other hydrodynamic conditions, in mini plants, and in the unusual,and costly presence of ethylene glycol) and not in harsh industrial operation. The considerable reduction of the laminar boundary layer in highly loaded packed tubular reactors increases the mass transfer coefficients, thus Oxeno claim the successful hydroformylation of 1-octene [25a,26,29c,49a,49e,58d,58f], The search for a new reactor design may also include operation in microreactors [59]. 

However, the detailed description of the FT product distribution together with the reactant conversion is a very important task for the industrial practice, being an essential prerequisite for the industrialization of the process. In this work, a detailed kinetic model developed for the FTS over a cobalt-based catalyst is presented that represents an evolution of the model published previously by some of us.10 Such a model has been obtained on the basis of experimental data collected in a fixed bed microreactor under conditions relevant to industrial operations (temperature, 210-235°C pressure, 8-25 bar H2/CO feed molar ratio, 1.8-2.7 gas hourly space velocity, (GHSV) 2,000-7,000 cm3 (STP)/h/gcatalyst), and it is able to predict at the same time both the CO and H2 conversions and the hydrocarbon distribution up to a carbon number of 49. The model does not presently include the formation of alcohols and C02, whose selectivity is very low in the FTS on cobalt-based catalysts. 

Renken 2005 Hessel et al. 2005a, b Golb and Hessel 2004 Kockmann et al. 2006). Here, some concepts and recent developments relevant to synthetic chemists will be summarized. Microreactor technology is beginning to be used in the fine chemical and pharmaceutical industries (Hessel et al. 2005b), and several success stories have been reported already (Thayer 2005 Rouhi 2004). 

Multiphase catalytic reactions, such as catalytic hydrogenations and oxidations are important in academic research laboratories and chemical and pharmaceutical industries alike. The reaction times are often long because of poor mixing and interactions between the different phases. The use of gaseous reagents itself may cause various additional problems (see above). As mentioned previously, continuous-flow microreactors ensure higher reaction rates due to an increased surface-to-volume ratio and allow for the careful control of temperature and residence time. 

Microreactors evolved from the process intensification concepts and microfabrication techniques developed for the microelectronics industry. Process intensification was pioneered in the 1970s, arguably by Imperial Chemical Industries (ICI) researcher Colin Ramshaw, who began developing technologies and approaches that considerably reduced the physical size of unit operations while maintaining their... 

Endothermic ammonia cracking is regarded as the reverse of the synthesis reaction, and since it is limited by heat transport, its efficiency can potentially be improved using microreactors. In industry, ammonia synthesis occurs at approximately 500 °C and 250 atm, and it is often represented by the following reaction ... 

However, microwave-assisted reactions are not easy to scale-up to industrial dimensions. In the attempt to make this reaction more interesting for industrial applications, microreactor conditions were evaluated in a cooperation of the Stevens and the Orm research groups [17]. 

W-Methyl-A/ -nitroso-p-toluenesulfonamide (MNTS) is an important precursor for the production of diazomethane. Diazomethane is then further converted to a range of useful molecules in the pharmaceutical and fine chemical industry [69]. Production of MNTS is a highly exothermic process and includes the presence of the extremely toxic materials. Stark et al. [70] have explored the application of microreactor technology for the production of this industrially valuable material, assuming that due to the efficient heat exchange and the closed system, microflow conditions provide a safer environment for these hazards. 

Roberge DM, Ducry L, Bieler N et al (2005) Microreactor technology a revolution for the fine chemical and pharmaceutical industries Chem Eng Technol 28(3) 318-323... 

Roberge DM, Zimmermann B, Rainone F et al (2008) Microreactor technology and continuous processes in the fine chemical and pharmaceutical industry is the revolution underway Org Process Res Dev 12(5) 905-910 www.syrris.com/. Accessed 14 Sept 2009... 

Acke DRJ, Stevens CV (2007) A HCN-based reaction under microreactor conditions industrially feasible and continuous synthesis of 3, 4-diamino-lH-isochromen-l-ones. Green (Them 9(4) 386-390... 

Currently, after each step in the synthesis process, a sample is analyzed to approve or reject the operation. Not only is this inefficient for the industry in general, this is also a stumbling block for a rapid scale-up. Controls and measurements of the process need to be accomplished in situ, which is again an issue that requires the chemists and chemical engineers to work together toward a solution. It may, in fact, involve lab-on-a-chip technologies and microreactors that were presented by other speakers in this workshop. 

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