CYTOS Pilot System

On the industrial scale, the comparison is based on the synthesis of m-anisaldehyde in a 400-L stainless-steel vessel, cooled to 193 K by a cryogenic system, and alternatively in the continuous Cytos Pilot System at 273 K. The cryogenic system for cooling of the extremely exothermic reaction works with ammonia as primary and nitrogen as secondary cooling medium. Per synthesis cycle, 23 kg of m-anisaldehyde were produced. 

The Cytos Pilot System is a 10-fold parallelized version of the Cytos Lab System [18] with identical fluidic behavior. Thus, nine Cytos microreactors were used for production with a cumulative product mass flow of 0.6 kg h , while alternately one reactor was treated with tetrahydrofuran in a rinsing cycle at a mass flow rate of 0.4kgh to avoid clogging of the microchannels. The continuously running Cytos Pilot System was cooled by an electrically tempered cooling system. 

Figure 1.8 Parallel microreactor system (the so-called CYTOS Pilot System) designed and commissioned by CPC for Clariant in 2001, for the manufacturing of diazo pigments. Source Reprinted from Ref [50], Copyright (2007), with permission from Elsevier.

Based on these positive results, a continuously operating Cytos Pilot Plant was constructed by CPC Systems GmbH and is used for fine chemical production. The results of the evaluation on production scale confirm those results obtained already during the process development stage, which have been discussed in detail elsewhere. ... 

Stainless steel is the material of choice for process chemistry. Consequently, stainless steel microreactors have been developed that include complete reactor process plants and modular systems. Reactor configurations have been tailored from a set of micromixers, heat exchangers, and tube reactors. The dimensions of these reactor systems are generally larger than those of glass and silicon reactors. These meso-scale reactors are primarily of interest for pilot-plant and fine-chemical applications, but are rather large for synthetic laboratories interested in reaction screening. The commercially available CYTOS Lab system (CPC 2007), offers reactor sizes with an internal volume of 1.1 ml and 0.1 ml, and modular microreactor systems (internal reactor volumes 0.5 ml to... 

Figure 4.25 Specialty plates for laboratory and pilot plant micro reactor modules of modified CYTOS systems (left). Standard off-the-shelf CYTOS system (right) [55].

The LCA methodology has been used by Krahsch and Kreisel to investigate the pros and cons of micro-reaction technology at the stage of process development. The motivation for this study was the question whether ecological improvements can be expected for the chosen model reaction performed in the micro-structured device Cytos produced by CPC Systems GmbH, Germany. Such improvements were the premise for the construction of a continuously operated pilot plant based on Cytos micro-reactors. 

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