Abstract: The invention is directed to a continuous hydrogenation process in which a hydrogenable compound is dissolved in a working solution with hydrogen and a heterogeneous catalyst. At least part of the hydrogen-containing waste hydrogenation gas generated in the reaction is compressed and then recycled into the hydrogenation reactor. A jet pump is used for the compression of the waste hydrogenation gas and a liquid or gaseous feedstock of the hydrogenation process is used as the motive agent. Preferred motive agents are the hydrogenation gas or a working solution recycled into the process. The process is particularly suitable for performing the hydrogenation step in the anthraquinone process for the production of hydrogen peroxide.

Abstract: A process for the continuous preparation of very highly concentrated hydrogen peroxide having a content of greater than 80 wt.%, especially over 98 wt.%, by suspension crystallization and after-treatment of the H2O2 crystals. The after-treatment takes the form of countercurrent washing in a hydraulic or mechanical washing column with a packed crystal bed. Hydrogen peroxide is disclosed having a concentration of from 99.9 to 100 wt.% and a content of TOC, nitrate, phosphate, nickel and tin of in each case less than 4 mg/l.

Abstract: The invention is directed to a continuous hydrogenation process in which a hydrogenable compound is dissolved in a working solution with hydrogen and a heterogeneous catalyst. At least part of the hydrogen-containing waste hydrogenation gas generated in the reaction is compressed and then recycled into the hydrogenation reactor. A jet pump is used for the compression of the waste hydrogenation gas and a liquid or gaseous feedstock of the hydrogenation process is used as the motive agent. Preferred motive agents are the hydrogenation gas or a working solution recycled into the process. The process is particularly suitable for performing the hydrogenation step in the anthraquinone process for the production of hydrogen peroxide.

Abstract: A process for the concentration of aqueous hydrogen peroxide by discontinuous crystallization. A cooling surface is arranged in a crystallizing vessel and first wetted with hydrogen peroxide and then cooled at a high cooling rate, whereupon seed crystals form. The cooling rate is at least 1 K/s, preferably from 10 to 30 K/s. When the vessel has been filled with H2O2 starting material, the latter crystallizes, starting from the seed crystals, and forms a crystal layer. When the mother liquor of lower H2O2 concentration has been discharged, there follows a sweating operation with a slow increase in temperature, as a result of which the H2O2 concentration in the crystal layer is increased further.

Abstract: In carrying out the hydrogenation stage of the anthraquinone process for the preparation of hydrogen peroxide in a hydrogenation reactor on a fixed bed catalyst of a particulate catalyst, the service life of the catalyst is increased in that the working solution comprising the reaction carrier and a gas phase comprising hydrogen, are passed through the hydrogenation reactor from the bottom upwards. The empty tube speed of the working solution is 0.05 to 100 m/h, preferably 10 to 50 m/h.

Abstract: A process for the continuous preparation of very highly concentrated hydrogen peroxide having a content of greater than 80 wt.%, especially over 98 wt.%, by suspension crystallization and after-treatment of the H2O2 crystals. The after-treatment takes the form of countercurrent washing in a hydraulic or mechanical washing column with a packed crystal bed. Hydrogen peroxide is disclosed having a concentration of from 99.9 to 100 wt.% and a content of TOC, nitrate, phosphate, nickel and tin of in each case less than 4 mg/l.

Abstract: A process for the concentration of aqueous hydrogen peroxide by discontinuous crystallization. A cooling surface is arranged in a crystallizing vessel and first wetted with hydrogen peroxide and then cooled at a high cooling rate, whereupon seed crystals form. The cooling rate is at least 1 K/s, preferably from 10 to 30 K/s. When the vessel has been filled with H2O2 starting material, the latter crystallizes, starting from the seed crystals, and forms a crystal layer. When the mother liquor of lower H2O2 concentration has been discharged, there follows a sweating operation with a slow increase in temperature, as a result of which the H2O2 concentration in the crystal layer is increased further.