Patent ID: 7488845

Claim:
A method for the safe operation of a continuously operated heterogeneously catalyzed gas-phase partial oxidation of at least one organic starting compound in a reactor whose feed gas mixture stream comprises at least one diluent gas substantially inert under the conditions of the heterogeneously catalyzed gas-phase partial oxidation, in addition to the at least one organic starting compound to be partially oxidized and molecular oxygen as an oxidizing agent and is produced by combining at least two different starting streams, in which inclusion of an online measurement of the concentration of one or more selected constituents in the feed gas mixture stream itself, in one or more of the starting streams producing the feed gas mixture stream and/or in the product gas mixture stream prevents the reactor from being fed with an explosive feed gas mixture stream or a feed gas mixture stream which is otherwise uncontrollable, where, for the online measurement, a part-stream of the gas stream to be analyzed in each case is passed continuously into a measuring cell of an analytical apparatus providing a measurement of concentration of said one or more selected constituents and, while the measurement is being carried out, is passed out of the measuring cell of the analytical apparatus into a discharge atmosphere, the gas stream to be analyzed, and/or the discharge atmosphere, being subject to pressure variations, wherein in said method the influence of variations of the pressure of the gas stream to be analyzed and/or of the discharge atmosphere on the measured pressure in the measuring cell in the analytical apparatus and hence on the result of the measurement a) is computationally corrected and/or b) minimized by keeping constant or regulated the measured pressure in the measuring cell of the analytical apparatus independently of the pressure of the gas stream to be analyzed and/or of the discharge atmosphere by means of a pressure control apparatus.