Technical rule 2013-05
Chemical micro process engineering deals with the development, manufacture and application of miniaturized apparatus for the manufacture of chemical intermediates and final products. Microreactors open doors for a small dimensioned, on-site production of difficult substances which is carried out on demand, at lower lost and with a lower risk compared with conventional methods. Recent research results of the Bundesanstalt für Materialprüfung und -prüfung (Federal Institute for Materials Research and Testing) and the Institut für Technische Chemie (Institute of Chemistry) of the University of Stuttgart, amongst others, have shown that micro-structured reactors are not inherently safe but there is a wider area of safe operating conditions in comparison with conventional reactors. When operating microreactors with explosive gas mixtures, for example, ethylene/oxygen, the explosive range can be restricted by the microstructures. The above research-oriented prestandard describes a method for safety-related testing of microreactors and micro-structured components which are intended to be operated in explosive ranges. A possible flashback through the microreactor into a macroscopic secondary chamber downstream the microreactor is tested. For this the test set-up is flooded with the explosive gas mixture and the gas mixture in the macroscopic primary chamber downstream the microreactor is ignited so a deflagration occurs which only spreads into the secondary chamber in case of flashback through the microreactor. The tests described in the prestandard shall take place in suitable locations and be carried out by suitably qualified experts allowing safe execution of explosion tests inclusive the necessary remote monitoring and remote control. The above prestandard has been prepared by Working Committee NA 055-03-13 AA "Mikroverfahrenstechnik" ("Micro process engineering"), a joint committee of the Laboratory Devices and Installations Standards Committee (FNLa) and the Chemical Apparatus Standards Committee (FNCA).