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
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/34—Regenerating or reactivating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/34—Chemical or biological purification of waste gases
  • B01D53/46—Removing components of defined structure
  • B01D53/48—Sulfur compounds
  • B01D53/50—Sulfur oxides
  • B01D53/508—Sulfur oxides by treating the gases with solids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/34—Chemical or biological purification of waste gases
  • B01D53/96—Regeneration, reactivation or recycling of reactants
• • 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
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/34—Regenerating or reactivating
  • B01J20/3433—Regenerating or reactivating of sorbents or filter aids other than those covered by B01J20/3408 - B01J20/3425
• • 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
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/34—Regenerating or reactivating
  • B01J20/345—Regenerating or reactivating using a particular desorbing compound or mixture
  • B01J20/3458—Regenerating or reactivating using a particular desorbing compound or mixture in the gas phase
• • 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
  • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
  • B01J20/30—Processes for preparing, regenerating, or reactivating
  • B01J20/34—Regenerating or reactivating
  • B01J20/3483—Regenerating or reactivating by thermal treatment not covered by groups B01J20/3441 - B01J20/3475, e.g. by heating or cooling

Definitions

• the present invention relates to the field of combustion and more particularly that of the regeneration of the sulfur oxide absorbents used to treat, by capturing said sulfur oxides, fumes originating for example from a means of combustion of a fuel containing sulfur.
• said fumes come from thermal power stations, ovens and boilers in industry.
• the present invention can also be applied for example to the effluents of various chemical or refining processes, workshops for the manufacture of sulfuric acid, roasting of ores, catalytic cracking units.
• French patent FR-2,636,720 discloses a boiler in which desulphurizing agents are injected into a specific zone, called the desulphurization chamber, interposed between the combustion chamber and the zone of heat recovery by convective exchange.
• the desulphurizing agents provided in this installation are preferably non-regenerable calcium absorbents, such as lime or limestone, or industrial residues with a high calcium carbonate content (sugar scum, stationery scum).
• Various improvements have been made to this type of boilers in order to increase the yield while having a high efficiency for the trapping of sulfur oxides in particular.
• FR-2 730 424 proposes to carry out the regeneration at the same time as the filtration of the spent absorbent, in a single reactor.
• the methods described above propose to use as regeneration gas a hydrogenated or hydrocarbon compound having a total carbon number less than 10 such as hydrogen, methane, ethane, propane, isobutane and / or a mixture of said gases.
• Hydrogen is the most suitable regeneration gas, since it does not lead to coking of the absorbent.
• its supply on the industrial site, in refineries for example can be problematic. Indeed, hydrogen is not always available in sufficient quantity in refineries, in particular when the conversion and / or hydrotreatment operations are important there.
• the present invention eliminates certain drawbacks encountered in previous installations and in particular related to corrosion at high temperature by hydrogen sulfide of the filtering and / or regeneration elements.
• the present invention relates to a process for regenerating a used solid absorbent from a desulphurization zone comprising the following steps: a) partial combustion of a regeneration gas, b) regeneration of the absorbent by bringing said absorbent into contact with the gaseous effluents from step a) in a chamber, c) cooling the gaseous mixture from step b) to a temperature above the formation temperature of liquid sulfur, d) filtration of the cooled mixture making it possible to separate the solid particles of regenerated absorbent and the gaseous fraction from said mixture.
• this process includes the following steps: e) cooling the gaseous fraction from step d) to a temperature below the sulfur liquefaction temperature, f) separating the resulting liquid sulfur and gaseous effluent said cooling.
• the gaseous effluents from step a) are mixed with the spent absorbent before the regeneration step.
• the gaseous effluents from step a) are mixed with the absorbent used during the regeneration step.
• the gaseous effluent from step f) is sent to the catalytic stages of a Claus chain.
• said regeneration gas comprises hydrogen sulphide.
• the gaseous effluents from step a) of combustion are partially cooled.
• the regenerated absorbent from the regeneration step and the filtration step is sent to a storage unit.
• the regenerated absorbent is mixed with a carrier gas and then sent to said desulfurization zone.
• the invention also relates to an installation for regenerating a used solid absorbent from a thermal desulphurization zone and comprising:
• regeneration means comprising means for introducing the gaseous effluents from said combustion means and means for introducing the spent absorbent
• means for filtering the cooled mixture comprising means for removing the gaseous fraction from said mixture and means for removing the solid particles of regenerated absorbent.
• This installation can include: - means for cooling the gaseous fraction from the filtration means to a temperature below the sulfur liquefaction temperature and means for separating the liquid sulfur and the gaseous effluent resulting from said cooling.
• the installation can comprise, between the combustion means and the regeneration means, a means for partial cooling of the gaseous effluents leaving said combustion means.
• the cooling means may include means for discharging the gaseous effluent which are connected to an inlet of a Claus unit.
• the regeneration device may comprise an enclosure internally coated with a refractory material and not corrodable.
• the regeneration device comprises a stirring means allowing the suspension in the gas phase of at least part of the solid particles of the absorbent.
• this stirring means can consist of vanes carried by a shaft.
• the proposed device can be easily integrated, by simply incorporating a regeneration device and a filtration means, into a Claus chain.
• a certain number of existing equipments in said chain such as the hearths and burners of the thermal stage or stages, the heat recuperators, the condensers, the catalytic conversion stages of the Claus chain can therefore advantageously be used for the implementation of the present process and / or installation.
• this regeneration mode avoids having gases very loaded with solids outside the regeneration device, as well as the risks of fouling and clogging that this may pose, and consequently the lowering of the exchange coefficients in the heat recovery means used.
• the regeneration device according to the invention is simple, robust, and minimizes the contact of the regeneration gas with the metal surfaces of the various elements making up the regeneration and high temperature filtration chain of the absorbent. Again, the risk of corrosion and blockage is limited.
• the present invention also makes it possible, by the combined effects of a partial combustion of the regeneration gas prior to said regeneration and the proximity of the heating means and of the regeneration zone, to limit the handling and the transport of corrosive fumes containing for example hydrogen sulfide. It also makes it possible to use a regeneration gas readily available on site. On the other hand, no recycling of the regeneration gas is necessary so that all the physical devices linked to said recycling can be eliminated.
• FIG. 1 is a schematic view of an installation according to the invention
• FIG. 1 shows schematically an embodiment of the invention according to which fumes from a heat generator (not shown) are treated by a regenerable absorbent such as a magnesium absorbent as formulated for example in patent FR-2,692,813.
• a regenerable absorbent such as a magnesium absorbent as formulated for example in patent FR-2,692,813.
• the absorbent is then sent to a chain which includes an oven 6 equipped with one or more burners 7 which partially burn, in the absence of oxygen, a gas rich in H 2 S (hydrogen sulfide) supplied by line 8
• the oxidizer which can be air or an oxygen-enriched gas, is supplied via line 9.
• the gaseous effluents from the furnace 6 contain inter alia hydrogen and hydrogen sulfide. They are at a temperature generally between 1000 and 1500 ° C. according to optimized operating conditions.
• These gaseous effluents are partially cooled in a cooling device 10 which can be, for example, an exchanger.
• This device is equipped with a temperature regulation means such as for example a bypass line 11 provided with a valve 12, preferably cooled, which can be a simple flap.
• This means of regulation is sized and / or controlled so as to maintain the temperature of the gaseous effluents at the inlet of a regeneration device 13 of the absorbent between approximately 600 ° C. and approximately 900 ° C., preferably between approximately 700 ° C and about 800 ° C, whatever the operating conditions of the oven 6 located upstream.
• the regeneration device 13 is designed so as to avoid any contact of the gaseous effluents with metallic parts at high temperature, that is to say beyond 350 ° C.
• This protection of the metal parts from gaseous effluents at high temperature can be done for example by cooling said metal parts by an internal circulation of a cold fluid and / or by isolating said parts by a layer of refractory ceramic materials, for example refractory concretes.
• the absorbent to be regenerated and the regenerative gas effluents are introduced at one end of the device, while the regenerated absorbent and the gaseous mixture resulting from the regeneration exit from the device at another end, respectively through lines 14 and 15.
• the absorbent to be regenerated from the storage zone 5 and circulating in the line 103 can be introduced either by a line 27 into the device 13, so that it is mixed with the gaseous effluents within this device, either by a line 28 in the pipe 29, downstream of said device 13 in the direction of circulation of the hot gaseous mixture, to be mixed with these gaseous effluents before introduction into said device.
• the regenerated absorbent can be directed towards a cooling device 16 such as for example a cooled screw which is traversed by a cooling fluid as represented by arrows in FIG. 1, then then towards a storage enclosure 17 by a line 26
• the gas mixture coming from the regeneration device 13 is sent to a cooling means 18 by the line 15 so that it does not exceed a temperature between 200 and 400 ° C, preferably 350 ° C, then passes then, via a link 33, in a filtration device 19, advantageously of the electrofilter type, which must operate at a temperature higher than the temperature of formation of liquid sulfur under the pressure conditions prevailing in said device 19 so that the sulfur is in the gas phase.
• the cooling means 18 can be equipped with a means for regulating the temperature of the gas mixture, such as for example a bypass line 20 provided with a valve 21, in order to maintain said temperature substantially constant at the inlet of the device. filtration 19, whatever the operating conditions upstream. Said inlet temperature will be determined on the one hand to minimize the problems of corrosion and on the other hand to avoid the liquefaction of the sulfur in the device 19.
• the absorbent recovered at the level of the filtration device 19 joins the storage capacity 17 by the line 22. The absorbent can then be mixed with a carrier gas, then returned to a combustion smoke treatment zone (not shown) downstream of the element 1.
• the gaseous fraction resulting from the filtration step then passes via a line 34 in a condenser 23 which brings the temperature of this gaseous fraction between about 100 and about 200 ° C and allows elemental sulfur to be recovered in liquid form.
• the sulfur is removed by line 24 and the gaseous effluent, cooled by line 25, is sent to the catalytic stages of a Claus chain (not shown in FIG. 1).
• FIG. 1 is a nonlimiting illustration of an embodiment of the regeneration device 13 of the absorbent shown in Figure 1.
• This device consists of a metal enclosure 100 substantially cylindrical, coated internally with a layer 101 d 'a refractory and non-corrodible material such as refractory concrete and delimiting a reaction zone 105.
• Said metallic enclosure can be partially or totally cooled by a jacket of water 102 to avoid any risk of corrosion which could appear in the event of local rupture of the layer of insulating refractory material 101.
• the absorbent is supplied by line 103 and a valve 104, preferably cooled, is placed on said line 103 to control and regulate the flow of absorbent.
• This valve also provides atmospheric isolation between the storage area of the absorbent 5 located upstream as shown in FIG. 1 and the reaction area 105 where the reducing gases such as hydrogen and hydrogen sulfide are known to be present. toxic and flammable.
• gases generated by partial oxidation of a gas mainly composed of hydrogen sulfide H 2 S arrive in the regeneration device 13 by line 29, also coated internally with refractory materials to protect its metal parts from corrosion.
• the valve 104 is connected to the metal enclosure 100 by the line 27 which is provided with a cooling device 106 to avoid the risks of corrosion by the hydrogen sulphide upstream.
• a non-corrosive gas such as steam, as a means of sweeping the line 27 to avoid contact of the valve 104 with the corrosive gases of the generator, could be envisaged without departing from the scope of the 'invention
• the contact between the spent absorbent and the partially burnt regeneration gas is therefore carried out near the entrance to the reaction zone 105.
• the mixing can also be carried out upstream of said zone, for example in line 29 via line 28 shown in FIG. 1.
• the absorbent falls under the effect of the forces of gravity in the enclosure 105 and forms a layer 107 there.
• This layer is stirred by an agitator 108 which can be cooled by the circulation of a fluid such as water.
• This agitator consists of a central shaft 109 and arms 110 which are provided at their ends with blades or equivalent parts 11 1.
• These blades 111 are intended to ensure good mixing of the solid particles of the absorbent and to suspension in the gas phase of some of the particles of this absorbent to promote contact and chemical reactions between the gas phase and the solid phase of the mixture. They also serve to advance the bed of particles in the enclosure, thanks to the slight inclination of the assembly.
• said gas phase comprises at most a few grams of solid particles per cubic meter of gas, that is to say between approximately 1 and approximately 50 grams and preferably between approximately 1 and approximately 10 grams.
• a major part of the regenerated solid particles of the absorbent is extracted from the enclosure under the effect of the forces of gravity by the line 112.
• the gaseous effluents and a minor part of the regenerated solid particles of this absorbent are evacuated by the line 15 to the cooling device 19 ( Figure 1).
• Devices such as baffles cooled or protected by refractory materials, can advantageously be placed upstream of the gas outlet by line 15, in order to minimize the entrainment of fine particles towards said line 15.
• the central shaft of the agitator is supported by support means carried by the front 113 and rear 114 faces of the enclosure 100.
• These support means may include, for example bearings, a device 115 for cooling the bearings and expansion resumption means 116 as well as means for supplying cooling fluid 117 to the agitator.
• the means allowing the mixing of the solid particles in the reaction zone 105 can be constituted by any known equivalent means allowing the best contacts and exchanges between said solid particles and the hot gases, in particular a helical screw without cooled core or a deck oven.
• a regeneration catalyst to be mixed with the spent absorbent.
• This catalyst can, for example, comprise at least one noble metal from group VIII of the periodic table of elements such as platinum or palladium or a compound comprising at least one element from the rare earth group, preferably cerium or an oxide of cerium.

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• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Health & Medical Sciences (AREA)
• Biomedical Technology (AREA)
• Environmental & Geological Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Treating Waste Gases (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)
• Gas Separation By Absorption (AREA)

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• 2001
  • 2001-04-27 FR FR0105842A patent/FR2823997B1/fr not_active Expired - Fee Related
• 2002
  • 2002-04-22 KR KR1020027017256A patent/KR100841968B1/ko not_active IP Right Cessation
  • 2002-04-22 EP EP02735481A patent/EP1385623A1/de not_active Withdrawn
  • 2002-04-22 JP JP2002585089A patent/JP2004529765A/ja active Pending
  • 2002-04-22 US US10/475,661 patent/US20040120866A1/en not_active Abandoned
  • 2002-04-22 WO PCT/FR2002/001380 patent/WO2002087755A1/fr active Application Filing
  • 2002-04-22 CA CA002444779A patent/CA2444779A1/fr not_active Abandoned

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