Abstract: The invention concerns a process for the preparation of hydrogen peroxide by the anthraquinone cyclic process. The process includes a regeneration stage in which working solution is regenerated by being brought into contact with an aqueous solution containing an alkyl anthrahydroquinone and/or an alkyl tetrahydroanthrahydroquinone in deprotonated form. The working solution regenerated in the regeneration stage is returned to the cyclic process.

Abstract: The invention concerns a process for the preparation of hydrogen peroxide by the anthraquinone cyclic process. The process includes a regeneration stage in which working solution is regenerated by being brought into contact with an aqueous solution containing an alkyl anthrahydroquinone and/or an alkyl tetrahydroanthrahydroquinone in deprotonated form. The working solution regenerated in the regeneration stage is returned to the cyclic process.

Abstract: A cyclic anthraquinone process for producing hydrogen peroxide using at least two differently substituted 2-alkylanthraquinones and/or their tetrahydro derivatives. The working solution to be used contains (i) at least one reaction carrier from the series 2-(4-methyl-3-pentenyl) anthraquinone (IHEAQ), 2-(4-methylpentyl) anthraquinone (IHAQ) and their di- and tetrahydro derivatives such as, in particular 2-(4-methylpentyl)-&bgr;-tetrahydroanthraquinone (THIHAQ), and (ii) at least one reaction carrier from the series of the 2-(C1- to C5)-alkylanthraquinones, especially 2-ethylanthraquinone (EAQ), and their tetrahydro derivatives. The reaction carriers according to (i) make up 5 to 95 molar %, especially 20 to 50 molar % of all reaction carrier. The method is distinguished by greater H2O2 capacity, improved hydrogenation kinetics and lesser susceptibility to disturbances. A method for making THIHAQ is also disclosed.

Abstract: A cyclic anthraquinone process for producing hydrogen peroxide using at least two differently substituted 2-alkylanthraquinones and/or their tetrahydro derivatives. The working solution to be used contains (i) at least one reaction carrier from the series 2-(4-methyl-3-pentenyl) anthraquinone (IHEAQ), 2-(4-methylpentyl) anthraquinone (IHAQ) and their di- and tetrahydro derivatives such as, in particular 2-(4-methylpentyl)-.beta.-tetrahydroanthraquinone (THIHAQ), and (ii) at least one reaction carrier from the series of the 2-(C.sub.1 - to C.sub.5)-alkylanthraquinones, especially 2-ethylanthraquinone (EAQ), and their tetrahydro derivatives. The reaction carriers according to (i) make up 5 to 95 molar %, especially 20 to 50 molar % of all reaction carriers. The method is distinguished by greater H.sub.2 O.sub.2 capacity, improved hydrogenation kinetics and lesser susceptibility to disturbances. A method for making THIHAQ is also disclosed.