Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
  • B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
  • B01J8/04—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds
  • B01J8/0496—Heating or cooling the reactor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/02—Apparatus characterised by being constructed of material selected for its chemically-resistant properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
  • B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
  • B01J8/04—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds
  • B01J8/0403—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the fluid flow within the beds being predominantly horizontal
  • B01J8/0423—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the fluid flow within the beds being predominantly horizontal through two or more otherwise shaped beds
  • B01J8/0438—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the fluid flow within the beds being predominantly horizontal through two or more otherwise shaped beds the beds being placed next to each other
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
  • B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
  • B01J8/04—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds
  • B01J8/0446—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the flow within the beds being predominantly vertical
  • B01J8/0449—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the flow within the beds being predominantly vertical in two or more cylindrical beds
  • B01J8/0453—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the flow within the beds being predominantly vertical in two or more cylindrical beds the beds being superimposed one above the other
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
  • B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
  • B01J8/04—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds
  • B01J8/0446—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the flow within the beds being predominantly vertical
  • B01J8/0476—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the flow within the beds being predominantly vertical in two or more otherwise shaped beds
  • B01J8/048—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the flow within the beds being predominantly vertical in two or more otherwise shaped beds the beds being superimposed one above the other
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B7/00—Halogens; Halogen acids
  • C01B7/01—Chlorine; Hydrogen chloride
  • C01B7/03—Preparation from chlorides
  • C01B7/04—Preparation of chlorine from hydrogen chloride
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
  • B01J2208/00008—Controlling the process
  • B01J2208/00017—Controlling the temperature
  • B01J2208/00106—Controlling the temperature by indirect heat exchange
  • B01J2208/00168—Controlling the temperature by indirect heat exchange with heat exchange elements outside the bed of solid particles
  • B01J2208/00212—Plates; Jackets; Cylinders
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
  • B01J2208/00008—Controlling the process
  • B01J2208/00548—Flow
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
  • B01J2208/00008—Controlling the process
  • B01J2208/00548—Flow
  • B01J2208/00557—Flow controlling the residence time inside the reactor vessel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
  • B01J2208/00008—Controlling the process
  • B01J2208/00628—Controlling the composition of the reactive mixture
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2208/00—Processes carried out in the presence of solid particles; Reactors therefor
  • B01J2208/02—Processes carried out in the presence of solid particles; Reactors therefor with stationary particles
  • B01J2208/023—Details
  • B01J2208/024—Particulate material
  • B01J2208/025—Two or more types of catalyst
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/02—Apparatus characterised by their chemically-resistant properties
  • B01J2219/0204—Apparatus characterised by their chemically-resistant properties comprising coatings on the surfaces in direct contact with the reactive components
  • B01J2219/0236—Metal based
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/02—Apparatus characterised by their chemically-resistant properties
  • B01J2219/025—Apparatus characterised by their chemically-resistant properties characterised by the construction materials of the reactor vessel proper
  • B01J2219/0277—Metal based
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/02—Apparatus characterised by their chemically-resistant properties
  • B01J2219/025—Apparatus characterised by their chemically-resistant properties characterised by the construction materials of the reactor vessel proper
  • B01J2219/0277—Metal based
  • B01J2219/0286—Steel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/02—Apparatus characterised by their chemically-resistant properties
  • B01J2219/025—Apparatus characterised by their chemically-resistant properties characterised by the construction materials of the reactor vessel proper
  • B01J2219/0277—Metal based
  • B01J2219/029—Non-ferrous metals
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/12—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of actinides
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D9/00—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/20—Improvements relating to chlorine production

Definitions

• the present invention relates to a process for the production of chlorine by catalytic
• Reaction zone emerging process gas mixture then through one of the respective
• Reactor system for the production of chlorine by catalytic gas phase oxidation of hydrogen chloride with oxygen by the method according to the invention.
• the catalysts used initially for the Deacon process for example supported catalysts with the active composition CuCl 2 , had only a low activity.
• Catalyst components also occur when using more active ruthenium chloride / oxide.
• the oxidation of hydrogen chloride to chlorine is also a
• the catalyst is used in the form of a fluidized, thermally stabilized bed.
• the catalyst bed is tempered via the outer wall, and according to DE 10 2004 006 610 A1, the fluidized bed is heated by means of a heat exchanger arranged in the bed.
• the effective heat removal of this process faces problems of non-uniform residence time distribution and catalyst wear, both of which result in a loss of revenue.
• Tube bundle reactors which require a complex to be controlled cooling.
• all described tube bundle reactors are very complex and cause high
• the object of the present invention is to provide such a method.
• it has set itself the task of providing a process for the production of chlorine by catalytic gas phase oxidation of hydrogen chloride with oxygen, wherein in a reactor, the process gas mixture in at least two separate reaction zones under adiabatic conditions of catalyst beds and reacts where the emerging from at least one reaction zone process gas mixture is then passed through a heat exchanger downstream of the respective reaction zone.
• the object is achieved in that the heat exchanger comprises plates stacked on each other and interconnected, the individual plates having at least two separate fluid flow channels according to a predetermined pattern and the plates provided with fluid flow channels arranged such that the process gas mixture in a first Strömungswegraum and the heat exchange medium used in the heat exchanger in a second Strömungswegides flow through the heat exchanger.
• a reactor is to be understood as the overall plant into which the educts hydrogen chloride and oxygen are introduced, react with each other and the
• the reactant hydrogen chloride can originate, for example, from the reaction of amines with phosgene for the synthesis of isocyanates.
• the Reactor comprises reaction zones which represent spatially separated regions in which the desired reaction takes place. Due to the corrosive reaction gases, the reactor is preferably constructed of stainless steel such as 1.4571 or 1.4828 or nickel 2.4068 or nickel base alloys such as 2.4610, 2.4856 or 2.4617, Inconel or Hastelloy.
• the reaction zones contain catalyst beds.
• Catalyst bed is understood here to mean an arrangement of the catalyst in all known forms, for example a fixed bed, a fluidized bed or a fluidized bed. Preferred is a fixed bed arrangement. This comprises a catalyst bed in the true sense, ie loose, supported or unsupported catalyst in any form and in the form of suitable packings.
• catalyst bed as used herein also encompasses contiguous areas of suitable packages on a support material or structured catalyst supports. These would be, for example, to be coated ceramic honeycomb carrier with comparatively high geometric surfaces or corrugated layers of metal wire mesh on which, for example, catalyst granules is immobilized.
• the heat exchanger is constructed so that it can be described as a succession of stacked and interconnected plates.
• the plates can be positively or materially connected to each other.
• An example of a cohesive connection is welding or diffusion bonding.
• fluid flow channels are incorporated, through which a fluid from one side of a plate to the other side, for example to the opposite side, can flow.
• the channels can be linear, thus forming the shortest possible path. However, they can also form a longer path by being laid out according to a wavy, meandering or zigzag pattern.
• the cross-sectional profile of the channels may, for example, be semicircular, elliptical, square, rectangular, trapezoidal or triangular. Having at least two separate fluid flow channels per plate means that these channels pass over the plate and the fluid flowing therein can not change between the channels.
• the flow path direction may be defined by the vector between the plane in which the starting points of the fluid flow channels lie and the plane in which the end points of the fluid flow channels of a plate or plate stack lie. It thus indicates the general direction of the flow of the fluid through the heat exchanger.
• a first flow path direction refers to the direction in which the process gas mixture flows through the heat exchanger or, in continuation, through the reaction zone.
• a second flow path direction designates the path of the heat exchange medium. This can flow, for example, in cocurrent, countercurrent or crossflow to the process gas mixture.
• the heat exchanger works so effectively that the temperature of the process gas mixture on entering the catalyst bed of the next reaction zone, even when the reaction starts, does not lead to a local overheating of the catalyst.
• a flow rate expressed in terms of annual tons of chlorine gas produced, of> 100 to ⁇ 400,000, from> 1000 to ⁇ 300,000 or from> 10,000 to ⁇ 200,000 can be achieved.
• an effective temperature control of the Deacon process is achieved, so that the formation of uncontrolled zones with elevated temperature, the so-called hot spots, in particular in the entrance area of the catalyst bed can be avoided.
• This enables service lives of the catalyst which, expressed in years, can be from> 1 to ⁇ 10, from> 2 to ⁇ 6 or from> 3 to ⁇ 4.
• the catalyst bed is formed as a structured packing. In a further embodiment of the present invention is the
• structured catalysts such as monoliths, structured packings, but also Shell catalysts primarily have a reduction in the pressure loss to the advantage.
• a further advantage of the use of structured catalysts is that shorter diffusion paths of the reactants are necessary in the thinner catalyst layers, which can be accompanied by an increase in the catalyst selectivity.
• fluid flow channels may be incorporated, wherein the hydraulic diameter of the fluid flow channels is> 0.1 mm to ⁇ 10 mm, preferably> 0.3 mm to ⁇ 5 mm, more preferably> 0.5 mm to ⁇ 2 mm.
• the specific surface area of the catalyst increases as the hydraulic diameter decreases. If the diameter is too small, too much pressure loss occurs. Furthermore, in the case of an impregnation with a catalyst suspension, a channel can also clog.
• the hydraulic diameter of the fluid flow channels in the heat exchanger is> 10 ⁇ m to ⁇ 10 mm, preferably> 100 ⁇ m to ⁇ 5 mm, more preferably> 1 mm to ⁇ 2 mm. With these diameters, an effective heat exchange is particularly ensured.
• the process comprises> 6 to ⁇ 50, preferably> 10 to ⁇ 40, more preferably> 20 to ⁇ 30 reaction zones.
• the use of materials can be optimized with regard to the conversion of HCl gas.
• a smaller number of reaction zones would result in an unfavorable temperature control.
• the inlet temperature would have to be set lower, which would make the catalyst less active.
• Especially the handling of the highly corrosive gases HCl, O 2 and Cl 2 requires resistant and correspondingly expensive materials for the reactor.
• hydrogen chloride and oxygen are simultaneously fed to the reactor.
• This can mean mixing in a prechamber without a catalyst bed or simultaneously introducing the gases into the first reaction zone.
• This has the advantage that the entire feed gas stream can be used for the absorption and removal of the heat of reaction in all catalyst beds. Furthermore, it is possible to direct the gases in an upstream heat exchanger to heat them. With the method according to the invention, a simplified apparatus of the reactor is also possible. The elimination of additional piping allows better temperature control. In general, it is also possible that the waste heat of the previous reaction stages is used to heat the process gas mixture before the next reaction zone.
• the length of at least one reaction zone is> 0.01 m to ⁇ 5 m, preferably> 0.03 m to ⁇ 1 m, more preferably> 0.05 m to ⁇ 0.5 m.
• the length here is to be understood as the length of the reaction zones in the flow direction of the process gas mixture.
• the reaction zones can all be the same length or different in length.
• the early reaction zones may be short, as there are sufficient starting materials available and excessive heating of the reaction zone should be avoided.
• the late reaction zones can then be long to increase the overall conversion of the process, with less fear of overheating the reaction zone.
• the stated lengths themselves have proven to be advantageous because at shorter lengths, the reaction can not proceed with the desired conversion and increases at greater lengths, the flow resistance to the process gas mixture too strong. Furthermore, the catalyst exchange is difficult to carry out at longer lengths.
• the catalyst comprises a carrier and a catalytically active ingredient / component.
• the catalyst in the reaction zones independently of one another comprises substances which are selected from the group comprising copper, potassium, sodium, chromium, cerium, gold, bismuth, iron, ruthenium, osmium,
• Particularly preferred compounds include: copper (I) chloride, copper (II) chloride, copper (I) oxide, copper (II) oxide, potassium chloride, sodium chloride, chromium (M) oxide, chromium (IV) oxide, chromium (VI) oxide, bismuth oxide, ruthenium oxide, ruthenium chloride, ruthenium oxychloride, rhodium oxide, uranium oxides, uranium chlorides and / or uranium oxychlorides.
• catalysts with catalytically active constituents comprising uranium oxides such as, for example, UO 3 , UO 2 , UO or the non-stoichiometric phases resulting from mixtures of these species, for example U 3 O 5 , U 2 O 5 , U 3 O 7 , U 3 O 8 , U 4 O 9 .
• the catalyst can be applied to a carrier.
• the carrier fraction may comprise: titanium oxide, tin oxide, aluminum oxide, zirconium oxide, vanadium oxide, chromium oxide, uranium oxide, silicon oxide, silica, carbon nanotubes, ceria or a mixture or compound of said substances, in particular mixed oxides, such as silicon-aluminum oxides.
• Further particularly preferred support materials are tin oxide, carbon nanotubes, uranium oxides such as UO 3 , UO 2 , UO or the non-stoichiometric phases resulting from mixtures of these species, such as U 3 O 5 , U 2 O 5 , U 3 O 7 , U 3 O 8 , U 4 O 9 .
• the ruthenium-supported catalysts can be obtained, for example, by impregnation of the support material with aqueous solutions of RuCl 3 and optionally a promoter for doping.
• the shaping of the catalyst can take place after or preferably before the impregnation of the support material.
• the catalysts are suitable as promoters alkali metals such as lithium, sodium, rubidium, cesium and especially potassium, alkaline earth metals such as calcium, strontium, barium and especially magnesium, rare earth metals such as scandium, yttrium, praseodymium, neodymium and especially lanthanum and cerium, furthermore cobalt and Manganese and mixtures of the aforementioned promoters.
• alkali metals such as lithium, sodium, rubidium, cesium and especially potassium
• alkaline earth metals such as calcium, strontium, barium and especially magnesium
• rare earth metals such as scandium, yttrium, praseodymium, neodymium and especially lanthanum and cerium, furthermore cobalt and Manganese and mixtures of the aforementioned promoters.
• the moldings can then be dried at a temperature of> 100 0 C to ⁇ 400 ° C under a nitrogen, argon or air atmosphere and optionally calcined become.
• the moldings are first dried at> 100 0 C to ⁇ 150 ° C and then calcined at> 200 ° C to ⁇ 400 ° C.
• the particle size of the catalyst is independently> 1 mm to ⁇ 10 mm, preferably> 1.5 mm to ⁇ 8 mm, more preferably> 2 mm to ⁇ 5 mm.
• the particle size may correspond to the diameter in the case of approximately spherical catalyst particles or, in the case of approximately cylindrical catalyst particles, to the extent in the longitudinal direction.
• the mentioned particle size ranges have been found to be advantageous since with smaller particle sizes, a high pressure loss occurs and with larger particles, the usable particle surface decreases in proportion to the particle volume and thus the achievable space-time yield is lower.
• the catalyst in various reaction zones, has a different activity, wherein preferably the
• An example of a change in catalyst activity would be when the activity in the first reaction zone is 30% of the maximum activity and increases per reaction zone in increments of 5%, 10%, 15% or 20% until the activity in the last reaction zone is 100%. is.
• the activity of the catalyst can be adjusted, for example, by the fact that, given the same base material of the support, the same promoter and the same catalytically active compound, the quantitative proportions of the catalytically active compound are different.
• particles without activity can also be added.
• a continuous exchange of a fixed bed catalyst is carried out.
• the absolute inlet pressure of the process gases before the first reaction zone is> 1 bar to ⁇ 60 bar, preferably> 2 bar to ⁇ 20 bar, more preferably> 3 bar to ⁇ 8 bar.
• the absolute inlet pressure determines the amount of starting material and the reaction kinetics in the process gas mixture. The ranges given have proven to be favorable, since lower pressures cause economically low, non-attractive conversions of the educts and at higher pressures the required compressor capacity becomes great, which entails cost disadvantages.
• the inlet temperature of the process gases upstream of a reaction zone is> 250 ° C to ⁇ 630 ° C, preferably> 310 ° C to ⁇
• the inlet temperature can be the same for all zones or individually different. It is responsible for how fast and how high the temperature in the process gas mixture rises. The selected inlet temperatures allow the highest possible conversion in the reaction zone, without the temperature within the zone increases to undesirable levels.
• the maximum temperature in a reaction zone is> 340 ° C to ⁇ 650 ° C, preferably> 350 ° C to ⁇ 500 ° C, more preferably> 365 ° C to ⁇ 420 ° C.
• the maximum temperature prevailing in a reaction zone may be the same for all zones or individually different. It can be adjusted by process parameters such as pressure or composition of the process gas mixture, activity of the catalyst and length of the reaction zone.
• the maximum temperature determines both the reaction conversion and the extent of discharge or deactivation of the catalyst. The temperatures chosen allow the highest possible conversion in the reaction zone, without the catalyst being significantly discharged or deactivated.
• control of the temperature in the catalyst beds can preferably be carried out by at least one of the following measures:
• the catalysts or the supported catalysts may have any desired form, for. As balls, rods, Raschig rings or granules or tablets.
• the sequentially connected reaction zones are operated at a changing average temperature.
• This can be set, for example, via the control of the heat exchangers connected between the catalyst beds. It means that the temperature of catalyst bed to catalyst bed can be both increased and decreased within a sequence of catalyst beds. Thus, it may be particularly advantageous to first increase the average temperature from catalyst bed to catalyst bed to increase the catalyst activity, and then to lower the average temperature in the following last catalyst beds again to shift the equilibrium. On the other hand, it may be advantageous to operate the successively connected reaction zones at an increasing average temperature. Thus, the reaction of the reactants initially with a greater safety margin be performed to the desired upper temperature limit. In the later stages of implementation, when there are fewer starting materials, the implementation can be continued by increasing the average temperature.
• the residence time of the process gases in the reactor is in total> 0.5 s to ⁇ 60 s, preferably> 1 s to ⁇ 30 s, more preferably> 2 s to ⁇ 10 s.
• Lower residence times and the associated low space-time yield are not economically attractive.
• no significant additional increase in the space-time yield occurs, so that such a procedure is likewise not economically attractive.
• the outlet temperature rises above the maximum desired temperature.
• unreacted reactant gases are reintroduced to the beginning of the reactor. Consequently, it is a circular process.
• Unreacted educt gases are in particular hydrogen chloride and oxygen.
• the heat exchange medium which flows through a heat exchanger selected from the group comprising liquids, boiling liquids, gases, organic heat carriers, molten salts and / or ionic liquids, wherein preferably water, partially evaporating water and / or water vapor selected become.
• a heat exchanger selected from the group comprising liquids, boiling liquids, gases, organic heat carriers, molten salts and / or ionic liquids, wherein preferably water, partially evaporating water and / or water vapor selected become.
• a heat exchanger selected from the group comprising liquids, boiling liquids, gases, organic heat carriers, molten salts and / or ionic liquids, wherein preferably water, partially evaporating water and / or water vapor selected become.
• partially evaporating water is to be understood that in the individual fluid flow channels of the heat exchanger liquid water and water vapor are present side by side. This offers the advantages of a high heat transfer coefficient on the side of the heat exchange medium, a high specific
• the constant evaporation temperature is advantageous because it allows a uniform heat removal across all reaction channels.
• the regulation of the Reaktandentemperatur can over the Adjustment of the pressure level and thus the temperature for the evaporation of the heat exchange medium done.
• Product stream > 5 K to ⁇ 300 K, preferably> 10 K to ⁇ 250 K, more preferably> 50 K to ⁇ 150 K. At lower logarithmic temperature differences, the required
• the process is conducted such that the space-time yield, expressed in kg of Cl 2 per kg of catalyst, is> 0.1 to ⁇ 10, preferably> 0.3 to ⁇ 3, more preferably> 0.5 to ⁇ 2.
• the heat of reaction removed in the heat exchangers is used for vapor recovery. This makes the overall process more economical and makes it possible, for example, to profitably operate the process in a compound plant or a composite site.
• the molar ratio of oxygen to hydrogen chloride before entering the first reaction zone is> 0.25 to ⁇ 10, preferably> 0.5 to ⁇ 5, more preferably> 0.5 to ⁇ 2.
• the process gases comprise an inert gas, preferably nitrogen and / or carbon dioxide.
• the inert gas has a proportion of the process gases from> 15 mol% to ⁇ 30 mol%, preferably> 18 mol% to ⁇ 28 mol%, more preferably> 20 mol% to ⁇ 25 mol%.
• the present invention furthermore relates to a reactor system for the production of chlorine by catalytic gas-phase oxidation of hydrogen chloride with oxygen by means of the process according to the present invention.
• the present invention relates to a reactor system wherein the heat exchanger comprises plates stacked and interconnected, the individual plates having at least two fluid flow channels separated from one another according to a predetermined pattern, and the fluid flow channeled plates being arranged such that the process gas mixture is in a first flow path direction and the heat exchange medium used in the heat exchanger in a second Strömungswegraum flow through the heat exchanger.
• the reactor system comprises> 6 to ⁇ 50, preferably> 10 to ⁇ 40, more preferably> 20 to ⁇ 30 reaction zones.
• Examples 1 and 2 relate to the temperature profile of the process gas mixture when it reacts in the reaction zones according to the inventive method and is cooled again in downstream heat exchangers. Furthermore, the examples relate to the conversion of HCl obtained.
• the process gas mixture flowed through a total of 24 catalyst stages, ie through 24 reaction zones. After each catalyst stage there was a heat exchanger which cooled the process gas mixture before entering the next catalyst stage.
• the process gas used was initially a mixture of HCl (38.5 mol%), O 2 (38.5 mol%) and inert gases (Ar, Cl 2, N 2, CO 2, a total of 23 mol%).
• the inlet pressure of the process gas mixture was 5 bar.
• the length of the catalyst stages, ie the reaction zones was uniformly 7.5 cm.
• the activity of the catalyst was adjusted to be in was equal to all catalyst stages. The procedure was carried out so that a load of 1.2 kg of HCl per kg of catalyst per hour was achieved. There was no replenishment of process gas components before the individual catalyst stages.
• the total residence time in the plant was 2.3 seconds.
• Fig.l The results are shown in Fig.l.
• the individual catalyst stages are listed on the x-axis, so that a spatial course of developments in the process is visible.
• the temperature of the process gas mixture is indicated on the left y-axis.
• the temperature profile over the individual catalyst stages is shown as a solid line.
• On the right y-axis the total conversion of HCl is indicated.
• the course of the conversion over the individual catalyst stages is shown as a dashed line.
• the inlet temperature of the process gas mixture before the first catalyst stage is about 340 ° C. Due to the exothermic reaction to chlorine gas under adiabatic conditions, the temperature rises to about 370 ° C, before the
• Process gas mixture is cooled by the downstream heat exchanger again.
• Inlet temperature before the next catalyst stage is about 344 ° C. By exothermic adiabatic reaction, it rises again to about 370 ° C. The sequence of heating and cooling continues.
• the inlet temperatures of the process gas mixture upstream of the individual catalyst stages increase with increasing number of stages. This is possible since the amount of reactants capable of reacting is lower in the later stages of the reaction and accordingly the risk of leaving the optimum temperature range of the process due to an exothermic reaction decreases. Consequently, the temperature of the process gas mixture can be kept closer to optimal for the respective composition.
• the process gas mixture flowed through a total of 18 catalyst stages, ie through 18 reaction zones.
• Each after a catalyst stage was a heat exchanger, which cooled the process gas mixture before entering the next catalyst stage.
• the process gas used at the outset was a mixture of HCl (38.5 mol%), O 2 (38.5 mol%) and inert gases (Ar, Cl 2 , N 2 , CO 2 , totaling 23 mol%)
• the inlet pressure of the process gas mixture was 5 bar.
• the length of the catalyst stages, ie the reaction zones, was uniformly 15 cm in each case.
• the activity of the catalyst was adjusted to increase with the number of catalyst stages.
• the relative catalyst activities were as follows:
• the procedure was carried out to achieve a load of 1.12 kg of HCl per kg of catalyst per hour. There was no replenishment of process gas components before the individual catalyst stages. The total residence time in the plant was 3.5 seconds.
• the results are shown in FIG.
• the individual catalyst stages are listed on the x-axis, so that a spatial course of developments in the process is visible.
• the temperature of the process gas mixture is indicated on the left y-axis.
• the temperature profile over the individual catalyst stages is shown as a solid line.
• On the right y-axis the total conversion of HCl is indicated.
• the course of the conversion over the individual catalyst stages is shown as a dashed line. It can be seen that the inlet temperature of the process gas mixture before the first catalyst stage is about 350 ° C. Due to the exothermic reaction to chlorine gas under adiabatic conditions, the temperature rises to about 370 ° C, before the process gas mixture is cooled by the downstream heat exchanger again.
• the inlet temperature before the next catalyst stage is again about 350 ° C. By exothermic adiabatic reaction, it rises again to about 370 ° C.
• the sequence of heating and cooling continues.
• the inlet temperatures of the process gas mixture upstream of the individual catalyst stages increase more slowly with increasing number of stages than in the case of Example 1. Overall, the fluctuation range of the process gas temperatures is even lower.
• the desired lower activity of the catalyst in the early stages makes it possible to introduce the process gas mixture with a higher inlet temperature, without fear of undesired overheating. Consequently, the temperature of the process gas mixture can be kept closer to optimal for the respective composition.

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