Abstract: Reactions between at least two fluid reactants are performed in a reactor comprising wall elements (1), slot-shaped reaction spaces (3) and cavities (5) for conducting a fluid heat-carrier through. Depending on the process and throughput, a modular structural design is chosen wherein an arbitrary number of wall elements (1) are assembled to a right-parallelepipedal block (24), the reaction spaces (3) are formed between lateral surfaces (2) of right-parallelepipedal wall elements (1), the reactants are introduced into the reaction spaces (3) from edge regions of one side of the block (24) and are conducted through the reaction spaces (3) in parallel flows and the fluid heat-carrier is conducted through the tubular cavities (5) extending in the interior of the wall elements (1).

Abstract: Reactions between at least two fluid reactants are performed in a reactor comprising wall elements (1), slot-shaped reaction spaces (3) and cavities (5) for conducting a fluid heatcarrier through. Depending on the process and throughput, a modular structural design is chosen wherein an arbitrary number of wall elements (1) are assembled to a right-parallelepipedal block (24), the reaction spaces (3) are formed between lateral surfaces (2) of right-parallelepipedal wall elements (1), the reactants are introduced into the reaction spaces (3) from edge regions of one side of the block (24) and are conducted through the reaction spaces (3) in parallel flows and the fluid heat-carrier is conducted through the tubular cavities (5) extending in the interior of the wall elements (1).

Abstract: The invention is relative to a method of producing hydrogen peroxide by direct synthesis in which hydrogen and oxygen are reacted in the presence of a heterogeneous, carrier-free or carrier-bound catalyst containing at least one noble metal in the presence or absence of a solvent and to a catalyst for carrying out the method.

Abstract: An aqueous solution of hydrogen peroxide is produced by direct synthesis from hydrogen and oxygen in the presence of a heterogeneous catalyst. According to the invention, a gas mixture comprising H.sub.2 and O.sub.2, essentially saturated or supersaturated with water (=containing fog) is fed into a reactor containing the catalyst. The volume ratio of the gas mixture fed in (standard liters per hour) to liquid removed (liters per hour) is adjusted to a value equal to or greater than 15,000, especially 20,000 to 50,000, and the gas mixture leaving the reactor is recycled after replenishment with H.sub.2, O.sub.2, and H.sub.2 O vapor. Solutions with high H.sub.2 O.sub.2 concentration can be obtained according to the invention without additional concentration.