CA1184169A - Regeneration process for poisoned claus alumina catalyst, including naoh activation - Google Patents
Regeneration process for poisoned claus alumina catalyst, including naoh activationInfo
- Publication number
- CA1184169A CA1184169A CA000419606A CA419606A CA1184169A CA 1184169 A CA1184169 A CA 1184169A CA 000419606 A CA000419606 A CA 000419606A CA 419606 A CA419606 A CA 419606A CA 1184169 A CA1184169 A CA 1184169A
- Authority
- CA
- Canada
- Prior art keywords
- catalyst
- claus
- poisoned
- sulfur
- activity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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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
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/20—Regeneration or reactivation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B17/00—Sulfur; Compounds thereof
- C01B17/02—Preparation of sulfur; Purification
- C01B17/04—Preparation of sulfur; Purification from gaseous sulfur compounds including gaseous sulfides
- C01B17/0404—Preparation of sulfur; Purification from gaseous sulfur compounds including gaseous sulfides by processes comprising a dry catalytic conversion of hydrogen sulfide-containing gases, e.g. the Claus process
- C01B17/0426—Preparation of sulfur; Purification from gaseous sulfur compounds including gaseous sulfides by processes comprising a dry catalytic conversion of hydrogen sulfide-containing gases, e.g. the Claus process characterised by the catalytic conversion
- C01B17/0434—Catalyst compositions
-
- 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
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/584—Recycling of catalysts
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
Abstract
"REGENERATION PROCESS FOR POISONED CLAUS ALUMINA CATALYST, INCLUDING NaOH ACTIVATION"
ABSTRACT OF THE DISCLOSURE
Poisoned catalyst is regenerated by first subjecting it to an oxidative burn-off and then soaking it in a base, preferably NaOH.
The dried product is comparable in Claus activity to fresh catalyst.
ABSTRACT OF THE DISCLOSURE
Poisoned catalyst is regenerated by first subjecting it to an oxidative burn-off and then soaking it in a base, preferably NaOH.
The dried product is comparable in Claus activity to fresh catalyst.
Description
q~
2 This invention relates -to a process for regenerating poisoned
3 Claus alumina catalys-t.
4 BACKGROUND OF THE INVENTION
A major source of elemental sulfur is sour natural gas pro-6 cessing in which the H2S and C02 are preFerentially removed from the gas ~r G~ r so/Y~/fs 7 by absorption in ethanolamin~. Upon saturation, the acid gas (containing 8 H2S and C02) is stripped ~`rom the amine solution.
9 Conversion of the toxic hydrogen sulfide to elemental sulfur and water is achieved by the modified Claus process. According to this 11 process, the hydrogen sulfide is first oxidized with a stoichiometric 12 amount of air in a reaction furnace at approximately 1200C. Elemental 13 sulfur, in an amount of 50 - 60% of the total sulfur content9 is formed, 14 along with water vapor, sulfur dioxide, carbonyl sulfide and carbon disulfide. The product stream is cooled to about 150C so that the 16 elemental sulfur is condensed and can be removed. The remaining gas, having 17 a stoichiometric ratio of H2S and S02 of 2:1, is then fed to a series of 18 adiabatic Claus catalytic converters, where -the Claus reaction (1) is 19 practised.
catalys ~ 3 2H2S ~ 52 ~ - - 2H20 ~ x Sx (1) 21 The Catalyst 22 Activated alumina catalyst, in the form of porous granules 23 ~ - 10 mm. in diameter, is normally employed in the converters. The catalyst 2~ has a reported composition and surface area as follows:
TABLE I
2 Componen-t Wt. %
3 Si02 0.02 4 Fe203 0.02 Na20 0.35 6 Loss on ignition 6.0 7 A1203 93.6 8 Surface area 325 m2/g 9 With use, the catalyst loses its effectiveness. This deterior-a-tion arises from the generation and deposition of aluminum sulfate, 1l carbon, and sulfur on the catalyst. High temperature and elevated partial 12 pressure of water in the Claus reactors favour sintering oF the catalyst. As 13 a result, the surface area and activity of the catalyst can be reduced 14 significantlY-By way of comparison, an exemplary analysis for a poisoned 16 and regenerated catalyst is:
7 TAeLE II
Wt. %
18 Component (Poisoned)(Regenerated) 19 Total sulfur as S04 , % 3.2 1.1 Water soluble S04 , % 2.2 21 Carbon, % 2.2 Trace 22 A1203 , % 59.l 90.8 23 Surface area, M2/g 88 158 24 Pore vol. , ml/g >0.1 0.4 Loss on ignition 20.2 7.3 26 Regeneration of the Catalyst 27 To applicant's knowledge, there are only two t~chniques which 28 have been developed for regenerating poisoned Claus catalyst.
~ ~ ~,fl~5~
1 The firs-t such technique involves a series of steps carried 2 out while the poisoned catalyst remains in place in -the conver-ters (in 3 situ regeneration). In this process, the operating temperature in the 4 converters is raised well above the sulfur dew point and maintained at that level for 24 - 36 hours while a dilute H2S-S02 stream is circulated 6 -through the reactor. Under these conditions sulfur is volatilized and re-7 moved.
8 The catalyst is then subjected to an oxidative burn-off using g air, to remove carbon, at a temperature in the order of 450 - 550C. How-lo ever, under this oxidative environment, any residual sulfur adsorbed on 1l the catalyst can lead to sulfate format;on. To reduce the S04 content, 12 a 4:1 H2S/S02 mixture is subsequently flowed through the oonverters, to reduce the aluminum sulfate to aluminum sulfide.
This in situ regeneration can take up to two weeks to complete and the degree of regeneration is often unsatisfactory and unreliable.
16 The other regeneration technique referred to is described in my 17 United States Patent 4,183,823. This process involves removing the poisoned 18 catalyst from the converters, regenerating it, and returning it to the 19 converters. The regeneration procedure comprises:
(1) leaching the aluminum sulfate and other soluble impurities 21 from the catalyst using hot water;
22 (2) drying the catalyst;
23 ~3) subjecting the catalyst to an oxidative burn-off to remove 24 the adsorbed sulfur and carbon, (4) and repeating the leach, if S04 content is high.
26 The drying step is necessary~ as the presence of water during 27 the oxidative burn-off step results in enhanced sintering of the 28 catalyst and loss of reactive surface area.
1 When this pa-tented process was examined for commercial appli-2 cation, it was Found that the leaching and drying steps were expensive and 3 de-tracted from the commercial viability of the process. Also, it was found4 that -the ~ctivity o-F the regenerated catalyst was not consistent from one batch to another.
7 In accordance with the present invention, it has been dis-8 covered that regeneration of poisoned Claus catalyst can be achieved by 9 a process comprising:
(1) first subjecting the catalyst to an oxidative burn-off, 11 to remove sulfur and carbon, followed by 12 (2) contacting the catalyst with a base, such as NaOH, to 13 enhance the activity of the catalyst and to reduce 14 sulfate content.
The catalyst regenerated in this manner was found to have a 16 Claus activity close to that,~of fresh catalyst, an increased surface area,17 and significantly reduced carbon and sulfur contents.
19 Figure 1 is a block diagram setting forth the steps of -the process;
21 Figure 2 is a schematic diagram showing the apparatus and 22 setting forth the conditions used to conduct the oxidative burn-ofF;
23 Figure 3 is a schematic diagram showing the reactor apparatus 24 used to carry out the Claus reaction to test the performance of catalyst batches;
26 Figure 4 is a plo-t of the eFfec-t of NaO~I concentration on the 27 Claus catalytic activity;
28 Figure 5 is a plot of -the activity profile for regenerated 29 alumina catalyst;
Figure 6 is a plot oF the activity profile for Fresh alumina 31 catalyst.
2 The invention is illustrated by -the following examples:
3 Example I
4 This example sets forth the best mode known to Applicant for practising the process.
6 Having reference to Figure 2, 500 grams o-F poisoned alumina7 catalyst , corresponding to the description of Table II above, were placed 8 in a furnace 1 to carry out an oxidative burn-ofF.
9 The furnace 1 comprised a steel vessel 2 having an inlet 3, at its upper end, connected to a source (not shown) of pressurized air. The 11 vessel was insulated and heated with external electric heating elements 12 4. The catalyst charge 5 was packed within the vessel 2 between upper 13 and lower layers 6, 7 of glass wool. An outlet 8 was provided at the base14 of the vessel 2, for the removal of gaseous products. A thermocouple 9 was provided to measure the temperature within the catalyst charge.
16 The catalyst charge was heated at a rate of 20C/minute in a17 flow of purified laboratory air of 500 ml./minute at atmospheric pressure18 to 500 - 530C and then maintained at this temperature for 6 hours.
19 Product gases, comprising mainly unused air, S02 and C02, were vented after scrubbing with NaOH solution.
21 The catalyst charge was then cooled to room temperature and 22 part of it was contacted with a base (NaOH) as follows.
23 A portion of 100 grams of the ca-talyst from the burn-off 2~ step was stirred into 150 ml. of 1.0 molar aqueous NaOH solution, at room -temperature. The mixture was left for 2 hours with periodic gentle 26 stirring. At the end of the 2 hours, the excess of NaOH was decan-ted and27 discarded. The catalyst was dried in an air oven at 100C.
28 The catalyst activity with respect to the Claus reaction 29 was tes-ted in the laboratory scale Claus reactor shown in Figure 3, as follows. About 80 grams oF the regenerated catalyst were packed into a 31 -tubular stainless s-teel reactor 10. The reactor 10 was positioned within a 32 furnace 1l.
1 Immediately above the top and bottom of the catalyst bed 12, 2 one centimeter thick layers 13 of stainless steel wire gauze were packed.
3 Close -to 60% of the H2S conversion takes place within a narrow 4 catalyst section at the top of the bed. Consequen-tly, sampling ports 13 were spaced along the length of the reactor, such that a range of conversion 6 could be obtained to enable extrapolation to zero conversion. The reactor 7 was also provided with three thermocouples 14.
8 Separate sources 15, 16 of hydrogen sulphide in nitrogen and 9 sulphur dioxide in nitrogen, respectively, were connected through lines 17, 18 and 19 to a heat exchanger 20. Flow to the heat exchanger was controlled 11 by micrometering valves 21, 22. A separate source 23 supplied water through 12 line 24 and metering pump 25 to join with the mixture entering the heat 13 exchanger.
14 A gas chromatograph (not shown) was used for sampling and analysis of both feed and product streams at will.
16 Laboratory determinations of -the catalytic activity of the 17 catalyst were performed at 300C. The catalyst was activated by heating to18 and maintaining it at 300C in flowing nitrogen for 4 hours. Then the 19 reactants ~ere introduced into the reactor. The inlet composition of the feed was maintained at 36 torr H2S, 18 torr S02 , 210 torr H20 and the balance 21 made up to slightly above atmospheric pressure with N2 . The total gas 22 flow rate through the reactor was 3 litres/min.
23 ~ Once the reactor temperature, partial pressures, and flow 24 rates of the reactants had stab;lized, approxima-tely 4 hours after start-up, samples of the reactor contents were taken from the ports 13 through 26 a line (not shown) connected with the gas chromatograph. The flow rate 27 through the sample system was 75 ml/min., abou-t 4 percent of the total flow.
2~3 Using a six port sample valve (not shown), a 2.0 ml sample of feed or 29 product stream, including water, could be analyzed by gas chromotography in about 7 minutes. For each sample por-t located at a different depth 31 along the bed, at least 4 samples were analyzed and the average taken.
32 Repeat analyses of the feed or product samples agreed wi-thin 3 percent.
6~
1 The rate of Claus reaction was determined from the consumption 2 oF H2S, since the peaks of the gas chromatogram for S02 and H20 showed 3 tails. The initial slopes of -the activity profiles seen in Figures 5 and 4 6 (which represent initial rate of reaction) and the activity profile which represents H2S conversion along the entire bed length, were used for Claus 6 activity comparisons set forth in said Figures.
7 Example _ 8 The procedure of Example I was practised on a number of g poisoned catalyst samples in accordance with Table II, while the time on stream was varied. The results for a catalyst are shown in Figure 5 1l in activity profile -Form.
12 The procedure of Example I was practised for a fresh catalyst sample, while the time on stream was varied. The results are shown in 1~ Figure 6 in activity profile form.
A comparison of the results in Figures 5 and 6 indicates that 16 the activity of the regenerated sample was comparable to that of the Fresh 17 sample.
18 Example III
19 The procedure of Example I was practised on a number of catalyst samples in accordance with Table II, except that the molarity 21 of the NaOH solution was varied9 as set forth in Figure 4. It will be 22 noted that the activity of the regenerated catalyst was a-t a maximum 23 when a molarity ~f .75 to 1.25, most preferably about 1.0, was used.
A major source of elemental sulfur is sour natural gas pro-6 cessing in which the H2S and C02 are preFerentially removed from the gas ~r G~ r so/Y~/fs 7 by absorption in ethanolamin~. Upon saturation, the acid gas (containing 8 H2S and C02) is stripped ~`rom the amine solution.
9 Conversion of the toxic hydrogen sulfide to elemental sulfur and water is achieved by the modified Claus process. According to this 11 process, the hydrogen sulfide is first oxidized with a stoichiometric 12 amount of air in a reaction furnace at approximately 1200C. Elemental 13 sulfur, in an amount of 50 - 60% of the total sulfur content9 is formed, 14 along with water vapor, sulfur dioxide, carbonyl sulfide and carbon disulfide. The product stream is cooled to about 150C so that the 16 elemental sulfur is condensed and can be removed. The remaining gas, having 17 a stoichiometric ratio of H2S and S02 of 2:1, is then fed to a series of 18 adiabatic Claus catalytic converters, where -the Claus reaction (1) is 19 practised.
catalys ~ 3 2H2S ~ 52 ~ - - 2H20 ~ x Sx (1) 21 The Catalyst 22 Activated alumina catalyst, in the form of porous granules 23 ~ - 10 mm. in diameter, is normally employed in the converters. The catalyst 2~ has a reported composition and surface area as follows:
TABLE I
2 Componen-t Wt. %
3 Si02 0.02 4 Fe203 0.02 Na20 0.35 6 Loss on ignition 6.0 7 A1203 93.6 8 Surface area 325 m2/g 9 With use, the catalyst loses its effectiveness. This deterior-a-tion arises from the generation and deposition of aluminum sulfate, 1l carbon, and sulfur on the catalyst. High temperature and elevated partial 12 pressure of water in the Claus reactors favour sintering oF the catalyst. As 13 a result, the surface area and activity of the catalyst can be reduced 14 significantlY-By way of comparison, an exemplary analysis for a poisoned 16 and regenerated catalyst is:
7 TAeLE II
Wt. %
18 Component (Poisoned)(Regenerated) 19 Total sulfur as S04 , % 3.2 1.1 Water soluble S04 , % 2.2 21 Carbon, % 2.2 Trace 22 A1203 , % 59.l 90.8 23 Surface area, M2/g 88 158 24 Pore vol. , ml/g >0.1 0.4 Loss on ignition 20.2 7.3 26 Regeneration of the Catalyst 27 To applicant's knowledge, there are only two t~chniques which 28 have been developed for regenerating poisoned Claus catalyst.
~ ~ ~,fl~5~
1 The firs-t such technique involves a series of steps carried 2 out while the poisoned catalyst remains in place in -the conver-ters (in 3 situ regeneration). In this process, the operating temperature in the 4 converters is raised well above the sulfur dew point and maintained at that level for 24 - 36 hours while a dilute H2S-S02 stream is circulated 6 -through the reactor. Under these conditions sulfur is volatilized and re-7 moved.
8 The catalyst is then subjected to an oxidative burn-off using g air, to remove carbon, at a temperature in the order of 450 - 550C. How-lo ever, under this oxidative environment, any residual sulfur adsorbed on 1l the catalyst can lead to sulfate format;on. To reduce the S04 content, 12 a 4:1 H2S/S02 mixture is subsequently flowed through the oonverters, to reduce the aluminum sulfate to aluminum sulfide.
This in situ regeneration can take up to two weeks to complete and the degree of regeneration is often unsatisfactory and unreliable.
16 The other regeneration technique referred to is described in my 17 United States Patent 4,183,823. This process involves removing the poisoned 18 catalyst from the converters, regenerating it, and returning it to the 19 converters. The regeneration procedure comprises:
(1) leaching the aluminum sulfate and other soluble impurities 21 from the catalyst using hot water;
22 (2) drying the catalyst;
23 ~3) subjecting the catalyst to an oxidative burn-off to remove 24 the adsorbed sulfur and carbon, (4) and repeating the leach, if S04 content is high.
26 The drying step is necessary~ as the presence of water during 27 the oxidative burn-off step results in enhanced sintering of the 28 catalyst and loss of reactive surface area.
1 When this pa-tented process was examined for commercial appli-2 cation, it was Found that the leaching and drying steps were expensive and 3 de-tracted from the commercial viability of the process. Also, it was found4 that -the ~ctivity o-F the regenerated catalyst was not consistent from one batch to another.
7 In accordance with the present invention, it has been dis-8 covered that regeneration of poisoned Claus catalyst can be achieved by 9 a process comprising:
(1) first subjecting the catalyst to an oxidative burn-off, 11 to remove sulfur and carbon, followed by 12 (2) contacting the catalyst with a base, such as NaOH, to 13 enhance the activity of the catalyst and to reduce 14 sulfate content.
The catalyst regenerated in this manner was found to have a 16 Claus activity close to that,~of fresh catalyst, an increased surface area,17 and significantly reduced carbon and sulfur contents.
19 Figure 1 is a block diagram setting forth the steps of -the process;
21 Figure 2 is a schematic diagram showing the apparatus and 22 setting forth the conditions used to conduct the oxidative burn-ofF;
23 Figure 3 is a schematic diagram showing the reactor apparatus 24 used to carry out the Claus reaction to test the performance of catalyst batches;
26 Figure 4 is a plo-t of the eFfec-t of NaO~I concentration on the 27 Claus catalytic activity;
28 Figure 5 is a plot of -the activity profile for regenerated 29 alumina catalyst;
Figure 6 is a plot oF the activity profile for Fresh alumina 31 catalyst.
2 The invention is illustrated by -the following examples:
3 Example I
4 This example sets forth the best mode known to Applicant for practising the process.
6 Having reference to Figure 2, 500 grams o-F poisoned alumina7 catalyst , corresponding to the description of Table II above, were placed 8 in a furnace 1 to carry out an oxidative burn-ofF.
9 The furnace 1 comprised a steel vessel 2 having an inlet 3, at its upper end, connected to a source (not shown) of pressurized air. The 11 vessel was insulated and heated with external electric heating elements 12 4. The catalyst charge 5 was packed within the vessel 2 between upper 13 and lower layers 6, 7 of glass wool. An outlet 8 was provided at the base14 of the vessel 2, for the removal of gaseous products. A thermocouple 9 was provided to measure the temperature within the catalyst charge.
16 The catalyst charge was heated at a rate of 20C/minute in a17 flow of purified laboratory air of 500 ml./minute at atmospheric pressure18 to 500 - 530C and then maintained at this temperature for 6 hours.
19 Product gases, comprising mainly unused air, S02 and C02, were vented after scrubbing with NaOH solution.
21 The catalyst charge was then cooled to room temperature and 22 part of it was contacted with a base (NaOH) as follows.
23 A portion of 100 grams of the ca-talyst from the burn-off 2~ step was stirred into 150 ml. of 1.0 molar aqueous NaOH solution, at room -temperature. The mixture was left for 2 hours with periodic gentle 26 stirring. At the end of the 2 hours, the excess of NaOH was decan-ted and27 discarded. The catalyst was dried in an air oven at 100C.
28 The catalyst activity with respect to the Claus reaction 29 was tes-ted in the laboratory scale Claus reactor shown in Figure 3, as follows. About 80 grams oF the regenerated catalyst were packed into a 31 -tubular stainless s-teel reactor 10. The reactor 10 was positioned within a 32 furnace 1l.
1 Immediately above the top and bottom of the catalyst bed 12, 2 one centimeter thick layers 13 of stainless steel wire gauze were packed.
3 Close -to 60% of the H2S conversion takes place within a narrow 4 catalyst section at the top of the bed. Consequen-tly, sampling ports 13 were spaced along the length of the reactor, such that a range of conversion 6 could be obtained to enable extrapolation to zero conversion. The reactor 7 was also provided with three thermocouples 14.
8 Separate sources 15, 16 of hydrogen sulphide in nitrogen and 9 sulphur dioxide in nitrogen, respectively, were connected through lines 17, 18 and 19 to a heat exchanger 20. Flow to the heat exchanger was controlled 11 by micrometering valves 21, 22. A separate source 23 supplied water through 12 line 24 and metering pump 25 to join with the mixture entering the heat 13 exchanger.
14 A gas chromatograph (not shown) was used for sampling and analysis of both feed and product streams at will.
16 Laboratory determinations of -the catalytic activity of the 17 catalyst were performed at 300C. The catalyst was activated by heating to18 and maintaining it at 300C in flowing nitrogen for 4 hours. Then the 19 reactants ~ere introduced into the reactor. The inlet composition of the feed was maintained at 36 torr H2S, 18 torr S02 , 210 torr H20 and the balance 21 made up to slightly above atmospheric pressure with N2 . The total gas 22 flow rate through the reactor was 3 litres/min.
23 ~ Once the reactor temperature, partial pressures, and flow 24 rates of the reactants had stab;lized, approxima-tely 4 hours after start-up, samples of the reactor contents were taken from the ports 13 through 26 a line (not shown) connected with the gas chromatograph. The flow rate 27 through the sample system was 75 ml/min., abou-t 4 percent of the total flow.
2~3 Using a six port sample valve (not shown), a 2.0 ml sample of feed or 29 product stream, including water, could be analyzed by gas chromotography in about 7 minutes. For each sample por-t located at a different depth 31 along the bed, at least 4 samples were analyzed and the average taken.
32 Repeat analyses of the feed or product samples agreed wi-thin 3 percent.
6~
1 The rate of Claus reaction was determined from the consumption 2 oF H2S, since the peaks of the gas chromatogram for S02 and H20 showed 3 tails. The initial slopes of -the activity profiles seen in Figures 5 and 4 6 (which represent initial rate of reaction) and the activity profile which represents H2S conversion along the entire bed length, were used for Claus 6 activity comparisons set forth in said Figures.
7 Example _ 8 The procedure of Example I was practised on a number of g poisoned catalyst samples in accordance with Table II, while the time on stream was varied. The results for a catalyst are shown in Figure 5 1l in activity profile -Form.
12 The procedure of Example I was practised for a fresh catalyst sample, while the time on stream was varied. The results are shown in 1~ Figure 6 in activity profile form.
A comparison of the results in Figures 5 and 6 indicates that 16 the activity of the regenerated sample was comparable to that of the Fresh 17 sample.
18 Example III
19 The procedure of Example I was practised on a number of catalyst samples in accordance with Table II, except that the molarity 21 of the NaOH solution was varied9 as set forth in Figure 4. It will be 22 noted that the activity of the regenerated catalyst was a-t a maximum 23 when a molarity ~f .75 to 1.25, most preferably about 1.0, was used.
Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for regenerating an alumina catalyst poisoned by use in modified Claus reaction converters and being contaminated with carbon, sulfur and sulfate and having a low surface area, comprising:
(a) first subjecting the catalyst to an oxidative burn-off to remove sulfur and carbon;
(b) then contacting the catalyst with a base to produce a catalyst with enhanced Claus activity.
(a) first subjecting the catalyst to an oxidative burn-off to remove sulfur and carbon;
(b) then contacting the catalyst with a base to produce a catalyst with enhanced Claus activity.
2. The process as set forth in claim 1 wherein the base used is aqueous sodium hydroxide solution.
3. The process as set forth in claim 1 wherein the base used is 0.75 to 1.25 molar aqueous sodium hydroxide solution.
4. The process as set forth in claim 3 wherein the burn-off is conducted at a temperature in the range of 500 - 530°C, and an excess of sodium hydroxide solution, over that needed to fill the pore volume of the catalyst , is used.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000419606A CA1184169A (en) | 1983-01-17 | 1983-01-17 | Regeneration process for poisoned claus alumina catalyst, including naoh activation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000419606A CA1184169A (en) | 1983-01-17 | 1983-01-17 | Regeneration process for poisoned claus alumina catalyst, including naoh activation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1184169A true CA1184169A (en) | 1985-03-19 |
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ID=4124359
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000419606A Expired CA1184169A (en) | 1983-01-17 | 1983-01-17 | Regeneration process for poisoned claus alumina catalyst, including naoh activation |
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| CA (1) | CA1184169A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0244014A2 (en) * | 1986-04-29 | 1987-11-04 | Shell Internationale Researchmaatschappij B.V. | Method for the regeneration of spent alumina-based catalysts |
-
1983
- 1983-01-17 CA CA000419606A patent/CA1184169A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0244014A2 (en) * | 1986-04-29 | 1987-11-04 | Shell Internationale Researchmaatschappij B.V. | Method for the regeneration of spent alumina-based catalysts |
| EP0244014A3 (en) * | 1986-04-29 | 1988-10-05 | Shell Internationale Research Maatschappij B.V. | Method for the regeneration of spent alumina-based catalysts |
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