Method for preparing an aqueous hydrogen peroxide solution directly from hydrogen and oxygen and implementing device

摘要

An aqueous hydrogen peroxide solution is prepared in a stirred reactor directly from hydrogen and oxygen. The hydrogen and oxygen are injected separately in the form of small bubbles into the lower part of the aqueous reaction medium. The reaction medium is rendered acidic by the addition of an organic acid and comprises a catalyst in a dispersed state. The ratio of the hydrogen molar flow rate to the oxygen molar flow rate is greater than 0.0416. Oxygen is also introduced into the continuous gas phase and/or the upper part of the aqueous reaction medium in an amount such that the molar ratio of hydrogen to oxygen in the continuous gas phase is less than 0.0416. The reaction medium may further comprise stabilizers or halides whereby the halide may be bromide and can be used in combination with bromine in free state. The device for preparing an aqueous hydrogen peroxide solution directly from hydrogen and oxygen comprises a stirred reactor fed continuously or non-continuously with working solution. The reactor comprises: One or more inlets for gaseous hydrogen into the lower part of the aqueous reaction medium and one or more inlets for gaseous oxygen optionally comprising hydrogen into the lower part of the aqueous medium. A pressure regulator, which enables the pressure prevailing inside the reactor to be kept constant by discharging excess unconsumed gaseous reactants One or more inlets for gaseous oxygen optionally comprising hydrogen into the upper part of the aqueous reaction medium which are controlled by an analyser of the gas flow exiting from the reactor, so that the hydrogen/oxygen molar ratio in the continuous gas phase is less than 0.0416.