Abstract:
Process for preparing isocyanates by reacting the corresponding amines comprised in at least one feed stream A with phosgene comprised in at least one feed stream P in a reactor plant comprising at least one mixing zone and at least one reaction zone, wherein feed stream A and/or feed stream P optionally comprise one or more inert materials and, during periods of time in which the flow S x of the amines used is below the flow S 0 of the amines used during operation at the nominal capacity of the reactor plant, (i) the ratio of phosgene to amine is increased and/or (ii) the concentration of the inert material or materials in the amine-comprising feed stream A and/or the phosgene-comprising feed stream P is increased compared to operation at the nominal capacity of the reactor.
Abstract:
The invention relates to a system for producing maleic acid anhydride by means of heterogeneously catalyzed gas phase oxidation of an inlet flow, comprising hydrocarbons having at least (4) carbon atoms per molecule, comprising a reactor having a bundle of reaction tubes into which a solid catalyst is introduced, on which the exothermal reaction of the inlet flow with a gas flow containing oxygen takes place, and one or more pumps and one or more heat exchangers located outside of the reactor, by means of which a heat carrier made of a salt melt is carried, permeating the intermediate reaction space between the reaction tubes and absorbing reaction heat, the temperature of the salt melt being in the range of 350 to 480 °C, characterized in that the reaction tubes are made of an alloyed, heat-resistant steel comprising either at least 0.5 wt % chromium, or at least 0.25 wt % molybdenum, or at least 0.5 wt % chromium and at least 0.25 wt % molybdenum.
Abstract:
The invention relates to a method for producing diisocyanates by gas-phase phosgenation, starting from an educt flow comprising the corresponding diamines and a phosgene, the educt flows each being separately converted to the gas phase and preheated to the reaction temperature of the gas-phase phosgenation, characterized in that waste heat from a plant for producing chlorine by heterogeneous catalyzed oxidation of hydrogen chloride using the Deacon method is used to this end.
Abstract:
The invention relates to a reactor for carrying out heterogeneously catalysed gas phase reactions, comprising an in-built element (11, 35) or multiple in-built elements (11, 35) arranged behind one another in the flow direction of the gas mixture of the heterogeneously catalysed gas phase reaction through the reactor (10), wherein the in-built elements extend over the entire reactor cross-section, characterised in that the one or multiple in-built elements (11, 35) are formed at least partially from a fibre-composite ceramic material.
Abstract:
The invention relates to a reactor (R) with a device (D) containing a gas and/or liquid-permeable base (B) in whose edge region a lateral boundary (W) is arranged which entirely surrounds the base (B) and forms a volume (V), said volume containing catalytic and/or non-catalytic moulded bodies (F), wherein at least one mesh made of noble metal and/or non-noble metal is located on the side opposing the base (B) in the upstream direction, and the catalytic and/or non-catalytic moulded bodies (F) are selected from (i) moulded bodies (F1) in the form of straight prisms whose base surface is selected from a triangle, rectangle, hexagon or fragments of these polygons, or (ii) a combination of the moulded bodies (F1) with moulded bodies (F2) that are smaller than the moulded bodies (F1), characterised in that groups of m to n moulded bodies (F1), where m/n is a whole number between 3-30 and n > m, are bound to form modules (M) in a metal cassette that is open upstream and closed with a gas-permeable base in the downstream direction, with their lateral surfaces side by side practically without a gap and with their longitudinal axis oriented in the vertical direction, such that the cross-section of the base is practically entirely covered, and which modules (M) are joined to one another in a mosaic-like manner practically without a gap, with the vertical orientation of the longitudinal axis of the moulded bodies (F1), optionally with the cooperation of a joint filling material.
Abstract:
The invention relates to a method for carrying out an exothermic gas phase reaction on a heterogeneous particulate catalyst, which is introduced into the contact tubes of two or more multi-tube reactors (R-l, R-Il) into the gaps between the thermal plates of two or more thermal plate reactors or in the beds of two or more bed reactors traversed by heat exchange means, wherein a heat transfer medium circulates through the intermediate space between the contact tubes (KR) of the two or more multi-tube reactors (R-l, R-Il), through the thermal plates of the two or more thermal plate reactors or through the heat exchange means of the two or more bed reactors, wherein the method comprises a production mode and a regenerating mode, characterised in that the two or more multi-tube reactors (R-l, R-Il), thermal plate reactors, or bed reactors have a single heat transfer medium circuit, and that always as many of the two or more multi-tube reactors (R-l, R-Il), thermal plate reactors, or bed reactors are operated in production mode that the released heat of reaction minus the amount of heat consumed for heating of the feed stream (1) in all multi-tube reactors (R-l, R-Il), thermal plate reactors or bed reactors to reaction temperature in the production mode is sufficient, such that the temperature of the heat transfer medium in the intermediate spaces between the contact tubes (KR) of all the multi-tube reactors (R-l, R-Il), in the thermal plates of all the thermal plate reactors or in the heat exchange means of the bed reactors is kept constant at a fluctuation range of a maximum of +/- 10 °C.