Abstract:
An ammonia converter is disclosed. The converter can alter the conversion of ammonia by controlling the reaction temperature of the exothermic reaction along the length of the reactor to parallel the equilibrium curve for the desired product. The converter can comprise a shell 101 and internal catalyst tubes 109. The feed gas stream enters the reactor, flows through the shell 101, and is heated by indirect heat exchange with the catalyst tubes 109. The catalyst tubes 109 comprise reactive zones 122 having catalyst and reaction limited zones 124 that can comprise inert devices that function to both separate the reactive zones, increase heat transfer area, and reduce the temperature of the reaction mixture as the effluent passes through the catalyst tube 109
Abstract:
A method of varying the temperature of a tube bundle reactor for catalytic gas phase reactions upon start-up and shut-down, the tube bundle reactor comprising a major reactor portion which includes a bundle of vertically disposed reactor tubes, upper and lower tubesheets tightly connected to the upper and lower ends, respectively, of the reactor tubes, and a reactor shell enclosing the tube bundle, a heat transfer medium having a melting temperature in the range of from 100° C. to 450° C. flowing around the outer surfaces of the reactor tubes during normal operation and being circulated in at least one circuit through the major reactor portion, comprising the steps: (a) varying the heat transfer medium temperature during circulation of the heat transfer medium; and (b) passing a temperature gas through the reactor tubes at least when the heat transfer medium is not yet or no longer circulated.
Abstract:
Conventional gas-phase catalytic oxidation reaction apparatus comprising two reactors for production of acrylic acid is subject to problems of high equipment costs for the reactors and piping, necessity for wide installation area and easy accumulation of carbides generated by autoxidation of acrolein. On the other hand, conventional reaction apparatus comprising a single reactor has the drawbacks that the composition of gas in the first stage reaction and in the second stage reaction cannot be optimized independently of each other, and that the allowable concentration of starting propylene is limited because of the risk of explosion. As a reaction apparatus to solve these problems, this invention provides a fixed bed shell-and-tube reaction apparatus comprising a single reactor, characterized in that the inside of the reactor is divided into two reaction zones of the first reaction zone and the second reaction zone, and that a space equipped with a mechanism for introducing a gaseous substance from outside is provided between the two reaction zones.
Abstract:
The present invention provides a heat exchange reactor comprising a reaction tube for obtaining a product (B) by exothermic reaction while passing a starting compound (A) therethrough and a reactor shell covering the surrounding of the reaction tube and having its interior divided into a plurality of regions along the passing direction of the starting compound (A), each of which regions is filled with a heat medium for carrying out heat exchange between the inside of the reaction tube and the heat medium independently for the respective separate regions; wherein the reactor is provided with a heater for heating the heat medium charged in the most upstream region among the separate regions independently from the heat media charged in other regions.
Abstract:
A fuel conversion reactor includes a shell-and-tube heat exchanger for controlling the temperature of a hot gaseous mixture produced by catalytic or non-catalytic reaction of a fuel with a gaseous fluid, and for controlling the temperature of the gaseous fluid and/or the fuel prior to the reaction. The reactor is either a catalytic or non-catalytic burner, or a fuel reformer for converting a fuel to hydrogen. A preferred reactor includes an outer shell having first and second ends and an inner surface, a primary inner shell extending into the outer shell, the primary inner shell defining a heat exchanging chamber and having primary and secondary ends, and a secondary inner shell having a first end located adjacent the secondary end of the primary inner shell. One or more outlet apertures are formed between the two inner shells for passage of the gaseous fluid out of the heat exchanging chamber. There are also a plurality of heat exchange tubes extending through the heat exchanging chamber between first and second tube sheets and connected to same. The first tube sheet is mounted in the primary inner shell while the second tube sheet is connected to the secondary inner shell. The tubes form passages for flow of the hot gaseous mixture in heat exchange contact with the gaseous fluid through the heat exchanging chamber, thereby preheating the gaseous fluid prior to reaction with the fuel. The adjacent ends of the inner shells form a disconnected joint and the secondary inner shell is free to move relative to the primary inner shell upon thermal expansion of the tubes.
Abstract:
The invention concerns a process for producing synthesis gas, SG, from hydrocarbons and/or recycled compounds, in which: a stream comprising a first feed F1 supplemented with steam undergoes steam reforming in a multi-tube reactor-exchanger R with reaction tubes (38) containing a steam reforming catalyst, and with a shell; the reaction tubes are heated by convection by circulating in the shell, in overall counter-current mode, a heating fluid HF external to said tubes, which fluid comprises a first combustion gas stream of a second feed F2, then said fluid HF is mixed in a complementary combustion zone (32, 34) internal to the shell with a third feed F3 and a gas comprising oxygen, to increase the temperature of the HF, then the stream of mixture obtained circulates in R to heat the reaction tubes in a complementary manner; SG is produced from the steam reforming effluent from F1 and optionally part or all of the HF.
Abstract:
A multi-zone jacketed pipe reactor (2; 60; 90; 130) for carrying out exothermic gaseous phase reactions and with at least one reaction zone (I) working with vaporisation cooling, at least one reaction zone (II) working with circulation cooling and, possibly, with additional zones (III, IV) is characterised in that one reaction zone (I) working with vaporisation cooling forms the first reaction zone to which is connected an additional reaction zone (II) working with circulation cooling. In this way there occurs at the beginning of the reaction, when the latter is most violent, very intensive cooling at a precisely controllable temperature and especially as well a temperature that is constant across the entire cross-section of the reactor while subsequently in a subsequent reaction zone working with circulating cooling by means of global counter-flow guidance of the heat transfer agent a constant cooling of the reaction gas is achieved.
Abstract:
Reforming reactor for the conversion of a process fluid into hydrogen comprising: a reforming section which is contained within a closed volume, a boiler section and a combustion section, in which said reforming section contains one or more catalyst tubes filled with reforming catalyst, said boiler section is provided with one or more flow channels for the passage of flue gas from the combustion section and said combustion section is provided with at least one burner, wherein the heat exchanging medium required for the reforming of said process fluid in the one or more catalyst tubes is a gas-liquid mixture that self-circulates and is encapsulated inside said closed volume and wherein at least a portion of said closed volume protrudes inside said boiler section.
Abstract:
Process and reaction unit for isothermal shift conversion of a carbon monoxide containing feed gas, the process comprising the steps of introducing the feed gas in a reaction unit into reactor tubes with a fixed bed of a shift conversion catalyst in a reaction zone; contacting the feed gas with the catalyst at conditions being effective in carbon monoxide shift conversion reaction with steam reactant to hydrogen and cooling the reaction by indirect heat exchange with a cooling agent by passing the cooling agent in a falling film along shell side of the reactor tubes and removing heated cooling agent from the falling film; passing hydrogen when it is formed by the shift conversion reaction through a hydrogen selective membrane to a permeate zone; withdrawing hydrogen from the permeate zone and carbon monoxide depleted feed gas from the reaction zone.
Abstract:
An object of the present invention is to provide a method of vapor phase catalytic oxidation which is capable of: efficiently removing heat of reaction; preventing the formation of hot spots; and efficiently providing a desired product. The invention provides a method of vapor phase catalytic oxidation of a substance to be oxidized with a gas containing molecular oxygen by means of a multitubular reactor, wherein the method comprises: performing a reaction of vapor phase catalytic oxidation under such conditions that a heat transfer coefficient of the heat medium is 1,000 W/(m2·K) or higher.