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
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/90—Regeneration or reactivation
  • B01J23/94—Regeneration or reactivation of catalysts comprising metals, oxides or hydroxides of the iron group metals or copper
• • 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
  • B01J8/0015—Feeding of the particles in the reactor; Evacuation of the particles out of the reactor
  • B01J8/0035—Periodical feeding or evacuation
• • 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
  • B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
  • B01J23/24—Chromium, molybdenum or tungsten
  • B01J23/26—Chromium
• • 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
  • B01J23/16—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
  • B01J23/24—Chromium, molybdenum or tungsten
  • B01J23/28—Molybdenum
• • 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
  • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
  • B01J23/72—Copper
• • 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
  • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
  • B01J23/74—Iron group metals
  • B01J23/745—Iron
• • 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
  • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
  • B01J23/74—Iron group metals
  • B01J23/75—Cobalt
• • 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
  • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
  • B01J23/74—Iron group metals
  • B01J23/755—Nickel
• • 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
  • B01J33/00—Protection of catalysts, e.g. by coating
• • 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
  • B01J38/00—Regeneration or reactivation of catalysts, in general
  • B01J38/04—Gas or vapour treating; Treating by using liquids vaporisable upon contacting spent catalyst
  • B01J38/12—Treating with free oxygen-containing gas
  • B01J38/14—Treating with free oxygen-containing gas with control of oxygen content in oxidation gas
• • 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
  • B01J2219/00049—Controlling or regulating processes
  • B01J2219/00245—Avoiding undesirable reactions or side-effects
  • B01J2219/00259—Preventing runaway of the chemical reaction
  • B01J2219/00263—Preventing explosion of the chemical 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
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/00049—Controlling or regulating processes
  • B01J2219/00245—Avoiding undesirable reactions or side-effects
  • B01J2219/00259—Preventing runaway of the chemical reaction
  • B01J2219/00265—Preventing flame propagation

Definitions

• the present invention relates to the method of treating a catalytic reactor. 5 Plant productivity is essentially determined by optimizing its design and operating costs.
• reactor operation is a key point. Many installation incidents are caused by reactors and catalysts.
• Catalytic materials can suffer greatly from the variation of certain parameters.
• the increase in temperature can lead to the sintering of catalytic sites and their supports.
• a change in the composition of the gas stream may result in the presence of "poison elements" may itself cause deactivation of the catalyst.
• the replacement of a catalyst represents a cost corresponding, on the one hand, to the price of the catalyst itself and, on the other hand, to the penalties applied by the end customer, who does not receive the products required for his own application during the replacement phase. unexpected.
• Indicators such as temperature measurements may reflect the part of the catalytic bed that is no longer active. In this case, the replacement of the catalyst can be optimized and skimming and replacement of a portion of the catalyst bed can be carried out.
• a problem that arises is to provide an improved process for treating a catalytic reactor.
• a solution of the present invention is a method of treating a catalytic reactor comprising a catalytic bed comprising successively:
• passivation is meant a very superficial oxidation step of the catalytic material.
• the method according to the invention may have one or more of the following characteristics:
• the oxidation layer has a thickness of between 0.3 and 10 nm, preferably between 0.3 and 3 nm.
• the passivation step comprises:
• the passivation step is carried out at a temperature below 200 ° C, preferably below 100 ° C;
• the passivation step is carried out at a pressure of less than 10 atm, preferably less than 5 atm;
• the introduction sub-step leads to the oxidation of the surface of the metal particles present on the catalytic bed.
• the surface of the particles corresponds to a surface layer of nanometric thickness.
• the oxidation during the introduction sub-step does not diffuse into the heart of the catalytic bed;
• monitoring of the temperature of the catalytic bed is carried out
• the catalytic reactor is a reactor based on copper, nickel, cobalt, iron, molybdenum, chromium ...
• the catalytic reactor is a reactor used for the synthesis of methanol, the hydrogenation of carbon dioxide, the hydrogenation of carbon monoxide, the methanation reaction, the reforming of methane with steam or CO 2, the reforming of alcohol (methanol, ethanol ...) with steam.
• inert gas means a gas which is inert with respect to the active sites of the catalytic bed, this gas may be nitrogen or argon.
• the reactor Before opening the reactor (step b), the reactor is depressurized at atmospheric pressure and cooled to room temperature by a stream of inert gas, preferably nitrogen. Then the catalytic reactor is opened while being swept by said inert gas. However, when opening the air can enter the catalytic reactor, and it is usual to measure 0.5 to 5% oxygen on the surface of the catalyst bed. In the absence of the passivation step carried out according to the invention before the reactor opening step, oxidation of the catalyst with sudden heating would be observed, inducing irreversible deactivation of the catalytic bed. Indeed, the heating will promote the sintering of the metal. Note that the rate of deactivation is dependent on the temperature range and the nature of the metal and its melting point. The deactivation rate also depends on the state of the catalyst microstructure.
• the passivation step according to the invention makes it possible to keep the proportion of the catalyst considered as being still active during the opening of the catalyst constant.
• the passivation step is carried out with an inert gas, for example nitrogen, and an oxidant, for example with ⁇ O2 or with CO2. , introduced into the inert gas.
• the passivation step is carried out at a temperature as low as possible generally at a temperature below 100 ° C, preferably at a temperature below 50 ° C.
• the amount of oxidant in the inert gas should be as low as possible. Since the oxidation reaction is exothermic, a small amount of oxidant makes it possible to minimize the rise in temperature.
• the amount of oxidant at the start of the passivation step should be of the order of a few tens of ppm, preferably between 50 and 100 ppm). Ideally, a monitoring of the temperature of the catalytic bed makes it possible to check that no phenomenon of hot spot occurs. The duration of the stage of Passivation depends on the size of the ferrule. If a temperature increase is detected (rise detected between 1 and 5 ° C) due to the oxidation reaction, it is possible to use this measurement of the temperature as an indicator of the progress of the reaction. Also, it is observed during the passivation step, the breakthrough of the heat front at the outlet of the catalytic reactor. Once the breakthrough of the heat front has been observed, the introduction of inert gas is repeated by increasing the amount of oxidant in the flow of inert gas until the composition of the external atmosphere is reached.
• the passivation step is carried out by means of a stream of nitrogen comprising an oxygen concentration of about 50 ppm at room temperature. room temperature and at atmospheric pressure.
• the passivation reaction was monitored by temperature control.
• the breakthrough of the heat front at the outlet of the catalytic reactor is observed.
• the introduction of inert gas is repeated by increasing the amount of oxidant in the nitrogen stream.
• the oxygen content in the nitrogen stream is gradually increased from 100 ppm to 1000 ppm. If the temperature of the catalyst bed remains stable in the presence of a nitrogen stream comprising a nitrogen content of 1000 ppm, it can be considered that the passivation step is complete.
• the catalytic reactor can then be opened after cooling to room temperature without the risk of reoxidation.
• FIG. 1 represents a first TPR signal obtained by means of a sample which has not undergone the passivation step according to the invention (solid line curve) and a second TPR signal obtained by means of a sample which has undergone Passivation step according to the invention (dotted line curve). It should be noted that the total reduction of the passivated sample is obtained quickly (in less than 30 minutes) and at a low temperature (200 ° C.) while the reduction of the non-passivated sample requires more time (40 minutes) and more energy (400 ° C).
• the passivation step before opening the catalytic reactor and skimming a part of the bed is relevant for many Cu, Ni, Co, Fe, Cr, Mo metal-based metal catalysts used, for example, in the following processes. :
• Cu-based catalyst synthesis of methanol, hydrogenation of CO2, hydrogenation of CO; Ni-based catalyst: reforming or pre-reforming reaction, methanation, ...

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
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• 2013
  • 2013-03-14 FR FR1352266A patent/FR3003185B1/fr active Active
• 2014
  • 2014-03-05 US US14/776,033 patent/US9604201B2/en active Active
  • 2014-03-05 EP EP14713532.1A patent/EP2969171A1/de not_active Withdrawn
  • 2014-03-05 WO PCT/FR2014/050496 patent/WO2014140455A1/fr active Application Filing

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