CN1082540C - Light hydrocarbon isomerizing catalyst and its preparation - Google Patents
Light hydrocarbon isomerizing catalyst and its preparation Download PDFInfo
- Publication number
- CN1082540C CN1082540C CN99105790A CN99105790A CN1082540C CN 1082540 C CN1082540 C CN 1082540C CN 99105790 A CN99105790 A CN 99105790A CN 99105790 A CN99105790 A CN 99105790A CN 1082540 C CN1082540 C CN 1082540C
- Authority
- CN
- China
- Prior art keywords
- zeolite
- heavy
- mordenite
- carrier
- catalyzer
- 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 - Lifetime
Links
Landscapes
- Catalysts (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
The present invention relates to a light hydrocarbon isomerization catalyst which is prepared from 0.01 to 2.0 wt% of VIII group metal and a compound zeolite carrier, wherein the compound zeolite carrier is prepared from 10 to 90 wt% of alumina and 10 to 90 wt% of compound zeolite prepared from 1 to 99 wt% of Beta zeolite and 1 to 99 wt% of mordenite. The catalyst is prepared in a mode that the hydrogen type mordenite, the hydrogen type Beta zeolite and the alumina are mixed and then are roasted to be prepared into a compound carrier, and then the VIII group metal is loaded. The catalyst is suitable for the isomerization of C5/C6 alkane, and an octane number of the C5/C6 alkane can be effectively increased.
Description
The present invention is a kind of catalyst for isomerizing light hydrocarbon and preparation method thereof, specifically, is a kind of VIII of being loaded with family metal, is applicable to C
5/ C
6The Catalysts and its preparation method of alkane isomerization.
As everyone knows, the effective ways that improve gasoline octane rating are to add tetraethyllead in gasoline, but because lead has very big hazardness to environment, especially in today of pay attention to day by day environment-friendly quality, plumbous quantity discharged has been subjected to strict restriction.Low lead or white gasoline just progressively replace doped fuel.Because isoparaffin has higher octane value, therefore with small molecular weight (C
5, C
6) normal paraffin change into the octane value that isoparaffin improves the light oil fraction, thereby the octane value that improves gasoline has crucial meaning.
One of isomerization method for light hydrocarbon commonly used is to carry out hydroisomerization reaction more than 250 ℃ with the zeolite type dual-function catalyst.The difunctional isomerization catalyst of described zeolite type mainly is meant with the crystalline silicate to be carrier, and aluminum oxide or other refractory oxide are binding agent, and supported V III family metal mainly is the catalyzer of platinum or palladium preparation.The carrier of this class catalyzer has acid function, can impel normal alkane isomerization, and used carrier mainly contains X type zeolite, y-type zeolite and mordenite at present.Because mordenite has good high-temperature stability, therefore be that the isomerization catalyst of preparing carriers is developed rapidly with the mordenite.As USP4,232,181, GB1039246, GB1189850, USP4,665,272 patent documentations such as grade are all described this kind Preparation of catalysts method in detail.But because the application of temperature of zeolite type dual-function catalyst is higher, and the equilibrium concentration of isomerized products is lower under the high temperature, particularly to normal hexane, higher temperature of reaction will influence in the isomerized products 2, and the 2-dimethylbutane (2, concentration 2-DMB), and 2,2-DMB has very high octane value, if its concentration reduces, will directly influence the octane value of isomerized products.Therefore, further improve the acidity of mordenite, the isomery selectivity that improves it seems very necessary.USP3,527,835 adopt the ammonium ion used when increasing the preparation h-mordenite and the ratio of zeolite metallic cation, promptly when ion-exchange, make the ratio of ammonium ion and zeolite metallic cation reach 100: 1 above methods and prepare acid strong h-mordenite, improve the performance of isomerization catalyst.CN87103444A then by increasing the surface-area of catalyzer, makes it reach 580 meters
2The above method of/gram is improved the performance of catalyzer.
The simple acidity of improving mordenite often can't make the isomery selectivity of catalyzer be greatly improved, and therefore, people are by introducing the acidity that chlorine or fluorine improve catalyzer in carrier.As USP4,789,655 introduce chlorine by the gas phase oxi-chlorination in the mordenite catalyst that carries platinum, described oxi-chlorination is to feed to contain oxygen, water, chlorine and/or muriatic gaseous mixture under 200～500 ℃ in catalyzer, and each component with respect to the ratio of mordenite is in the gaseous mixture: water 0.03～4 heavy %, chlorine and/or muriate (in chlorine) 0.5～10 heavy %.USP3,932,554 adopt fluorine-containing halon such as CF
4, CCl
3F, CHCl
2F etc. contact with the mordenite catalyst that carries platinum or palladium, make the modified catalyst that fluorine content is at least 0.86 heavy %.Though the catalyzer of above-mentioned chlorine or fluorine modification has good isomerization performance, in the catalyzer use, chlorine or fluorine can run off gradually along with the carrying out of reaction, cause catalyst activity reduction, corrosion of equipment.
In recent years, the Beta zeolite is owing to the characteristic Application Areas that itself has constantly enlarges.The existing report that the Beta zeolite is used for light hydrocarbon isomerization in the patent documentation, as USP5,095,169 to disclose a kind of be the isomerization catalyst of preparing carriers with activatory Beta zeolite, and this patent mainly is to improve the activation method of Beta zeolite, this method with the Beta zeolite at 600～700 ℃, being preferably in 650 ℃ handles, remove the strong acid in the Beta zeolite, keep weak acid, obtain activatory Beta zeolite.This activatory Beta zeolite is made the h-type zeolite carrier through ammonium exchange, increase with the selectivity of the isomerization catalyst of this preparing carriers.
The purpose of this invention is to provide a kind of isomery selectivity height, activity stability is good and liquid yield is high catalyst for isomerizing light hydrocarbon.
Another object of the present invention provides a kind of above-mentioned Preparation of catalysts method.
Catalyst for isomerizing light hydrocarbon of the present invention is made up of the VIII family metal of 0.01～2.0 heavy % and composite zeolite carrier, described composite zeolite carrier is made up of the aluminum oxide of 10～90 heavy % and the composite zeolite of 10～90 heavy %, and wherein composite zeolite is the Beta zeolite of 1～99 heavy % and the mordenite of 1～99 heavy %.
Described VIII preferred platinum of family's metal or palladium, its content are preferably 0.15～0.8 heavy %.
The content of aluminum oxide is preferably 15.0～40.0 heavy % in the described composite zeolite carrier, the high purity aluminium oxide that preferred aluminum alkoxide hydrolysis makes, and this high purity aluminium oxide is selected from high-carbon (C
4Above) aluminum alkoxide the hydrolysis high purity aluminium oxide or the low-carbon (LC) (C that make
4Below) high purity aluminium oxide that makes of aluminum alkoxide hydrolysis, or the mixture of the two, the method preparation that the high purity aluminium oxide that described low-carbon alkoxy aluminium hydrolysis makes adopts CN1032951A to announce.
The content of Beta zeolite preferred 30.0～75.0 heavy %, most preferably 50.0～75.0 heavy % in the described composite zeolite.The sodium content of mordenite and Beta zeolite all should be less than 0.3 heavy % in the composite zeolite, and the sodium content in mordenite and the Beta zeolite is preferably in the scope of 0.01～0.08 heavy %.
Described mordenite can be natural or the synthetic mordenite, and the mol ratio of its silica (silica alumina ratio) is 5～80, is preferably 10～60.The mol ratio of the silica of used Beta zeolite is 5～80, is preferably 10～60.
Preparation of catalysts method of the present invention comprises:
(1) sodium type mordenite, sodium type Beta zeolite are carried out ion-exchange with acid or ammonium salt solution and make h-type zeolite,
(2) h-mordenite and Hydrogen Beta zeolite are pressed 1～99: 99～1, preferably 1: 30～75 weight ratio is mixed and made into composite zeolite, the mixed of again composite zeolite and aluminum oxide being pressed butt weight ratio 10～90: 90～10 is even, pinch through mixing, moulding, roasting make the composite zeolite carrier
(3) with after containing the above-mentioned composite zeolite carrier of solution impregnation of VIII family metal, dry, roasting makes catalyzer.
(1) step was to convert na-pretreated zeolite to h-type zeolite in the described method, and conversion method can adopt routine techniques to carry out.As na-pretreated zeolite is carried out ion-exchange with acid or acidic salt solution under 90～95 ℃,, be preferably less than the h-type zeolite of 0.08 heavy % to make sodium content less than 0.3 heavy %.Sodium type mordenite described in the aforesaid method or sodium type Beta zeolite all can adopt the method for ion-exchange to convert h-type zeolite to.Hydrochloric acid is generally selected in acid used in the ion exchange process for use, and its concentration is preferably 0.1～5.0 mol, and used acidic salt solution is generally selected ammonium chloride solution for use.Described ion exchange process can repeat repeatedly, till the silica alumina ratio of zeolite reaches requirement.
(2) step of described method be with h-mordenite and Hydrogen Beta zeolite and aluminum oxide be mixed in proportion be combined even after, adding rare nitric acid or extrusion aids such as acetic acid, citric acid mixes and pinches, and then extrusion moulding, room temperature～150 ℃ drying, 450～850 ℃ of roastings make the composite zeolite carrier.The carrier of extrusion moulding is stripe shape preferably, also can be other shape, as sheet shape, cloverleaf pattern.The method of carrier moulding also can adopt the method for dripping ball or spin to make the ball-type carrier except that extrusion moulding.
The preferred Platinic chloride of solution, the acid of chlorine palladium, the platinum ammonium complex ion that contain VIII family metal described in the step (3), the amount of flooding the solution of the used VIII of containing family metal should make bullion content wherein satisfy desired bullion content in the catalyzer.During dipping, the volume ratio of steeping fluid and carrier is preferably 3～1.2: 1.Dipping back carrier room temperature～150 ℃ of dryings, 450～850 ℃ of roastings promptly make catalyzer of the present invention.
Catalyzer of the present invention is applicable to C
5/ C
6The hydroisomerization reaction of normal paraffin.Suitable isomerization reaction condition is as follows: 200～350 ℃ of temperature, preferably 230～300 ℃; Pressure 1.0～3.0MPa, preferably 0.5～2.0Mpa; Feed weight air speed 0.2～10.0 hour
-1, preferably 0.5～3.0 hour
-1Hydrogen hydrocarbon mol ratio 0.1～5.0, preferably 0.5～3.0.
Catalyzer of the present invention itself has more highly acid Beta zeolite owing to containing, thereby improved the acidity of catalyzer, the activity and the selectivity of isomerization catalyst have been improved, and the institute of Beta zeolite inherent acidity own can not run off gradually along with the carrying out of reaction, therefore make the stability of catalyzer strengthen, also can not cause the corrosion of device.Catalyzer of the present invention under the situation active, that selectivity is suitable, can obtain higher liquid yield than being the comparative catalyst of carrier with the Beta zeolite.
Further specify the present invention below by example, but the present invention is not limited to this.
Example 1～3
Following examples preparation catalyzer of the present invention.
Get 100 gram sodium type mordenites (Fushun No.3 Petroleum Factory's production), its composition sees Table 1, is put in the three-necked bottle, adds the NH of 800 milliliter of 1 mol
4Cl solution was 90～95 ℃ of exchanges 3 hours, filter, the gained solid washs with deionized water, 120 ℃ of dryings 3 hours, repetitive operation twice, the HCl with 800 milliliter of 1 mol handled 3 hours at 90～95 ℃ again, filter, wash to filtrate with deionized water and be neutral, 600 ℃ of roastings 6 hours, making sodium content is 0.03 heavy %, SiO
2/ Al
2O
3The h-mordenite of mol ratio 23.4 (fluorescence spectrum method for measuring).
Get 100 gram sodium type Beta zeolites (Fushun No.3 Petroleum Factory's production), its composition sees Table 1, makes the Hydrogen Beta zeolite that sodium content is 0.03 heavy % by above-mentioned ammonium switching method.
With above-mentioned h-mordenite, Hydrogen Beta zeolite and high purity aluminium oxide (SB powder, Germany CONDEA company produces) mix by the vehicle group of listing in the table 2 is proportional, the salpeter solution that added volume ratio and be 1: 1 mixes to be pinched, add nitric acid and solid powder volume ratio be 1: 1.6, extruded moulding, 120 ℃ of dryings 2 hours, 550 ℃ of roastings made the composite zeolite carrier in 4 hours.
Get composite zeolite carrier 100 gram, with the platinum acid chloride solution dipping of 45 milliliter of 8.6 mol 24 hours, 120 ℃ of dryings 4 hours, roasting made catalyst A～C of the present invention in 4 hours in 550 ℃ of air, and platinum content is 0.35 weight % in the gained catalyzer.The support of the catalyst composition sees Table 2.
Example 4
Method by CN1032951A prepares the HP aluminum oxide powder, and the feed ratio by example 2 prepares catalyzer F again.The support of the catalyst composition sees Table 2.
Example 5
Sodium type mordenite, sodium type Beta zeolite are undertaken making h-type zeolite after the ammonium exchange by the method for example 1, make catalyzer G by the feed ratio of example 2 again.The support of the catalyst composition sees Table 2.
Example 6
According to the method described in the example 1 sodium type mordenite, sodium type Beta zeolite are carried out the ammonium exchange, use HCl 90～95 ℃ of processing again, make silica alumina ratio and be 59.0 h-mordenite and silica alumina ratio and be 58.0 Hydrogen Beta zeolite, make catalyzer H by the feed ratio of example 2 again.The support of the catalyst composition sees Table 2.
Comparative Examples 1～2
Method according to example 1 prepares comparative catalyst D, E, and the carrier of different is comparative catalyst D is made up of mordenite and aluminum oxide, and the carrier of catalyzer E is made up of Beta zeolite and aluminum oxide.
Example 7～14
Following example carries out the isomeric hexane reaction test with the small stationary bed reaction device to catalyzer provided by the invention and comparative catalyst.
Catalyst for isomerizing light hydrocarbon is packed in the small stationary bed bioreactor, Intake Quantity is 12 milliliters, is warming up to 600 ℃, feeds hydrogen reducing 4 hours, feed hexane then and carry out isomerization reaction under 250 ℃, 1.47MPa condition, the reaction feed weight space velocity is 1.0 hours
-1, hydrogen hydrocarbon mol ratio is 2.7.Reaction result sees Table 3.In the table 3
As shown in Table 3, the catalyzer of the present invention's preparation has higher transformation efficiency and isomerization selectivity than the comparative catalyst who with the mordenite is carrier.Than being the comparative catalyst of carrier, keeping optionally simultaneously, less than C than high isomerization with the Beta zeolite
5Component output lower, that is to say with catalyzer of the present invention and carry out light hydrocarbon isomerization reaction, can obtain higher liquid yield, can produce more stop bracket gasoline.
Example 15
This examples preparation is carried the catalyzer of palladium and is carried out the isomerization reaction evaluation.
Method by example 1 prepares catalyzer M, and different is with the chlorine palladium acid substitution Platinic chloride dipping complex carrier of 40 milliliter of 10.26 mol.Palladium content among the catalyzer M is 0.34 heavy %.
Get 12 milliliters of catalyzer M, carry out the light hydrocarbon isomerization reaction by the condition of example 7, but reactant is the mixture of Skellysolve A and normal hexane, Skellysolve A and normal hexane weight ratio are 60: 40 in this mixture, and reaction result sees Table 4.
C in the table 4
6Isomerization rate, C
6The isomerization selectivity is with example 7
Table 1
Table 2
| Instance number | Carrier is formed, heavy % | The catalyzer numbering | ||
| Mordenite | The Beta zeolite | Aluminum oxide | ||
| 1 | 20 | 60 | 20 | A |
| 2 | 40 | 40 | 20 | B |
| 3 | 60 | 20 | 20 | C |
| 4 | 40 | 40 | 20 | F |
| 5 | 40 | 40 | 20 | G |
| 6 | 40 | 40 | 20 | H |
| Comparative Examples 1 | 80 | - | 20 | D |
| Comparative Examples 2 | - | 80 | 20 | E |
Table 3
22DMB-2 in the table 3,2-dimethylbutane, 23DMB-2,3-dimethylbutane
The 2MP-2-methylpentane, 3MP-3-methylpentane, nC
6-normal hexane
Table 4
| Instance number | The catalyzer numbering | ＜C 4Component, heavy % | C 5Isomerization rate, heavy % | C 6Isomerization rate, heavy % | C 6The isomerization selectivity, heavy % |
| 15 | M | 0.4 | 61.0 | 82.9 | 20.0 |
Claims (9)
1, a kind of catalyst for isomerizing light hydrocarbon, form by the platinum of 0.01～2.0 heavy % or palladium and composite zeolite carrier, described composite zeolite carrier is made up of the aluminum oxide of 10～90 heavy % and the composite zeolite of 10～90 heavy %, and wherein composite zeolite is the Beta zeolite of 1～99 heavy % and the mordenite of 1～99 heavy %.
2, according to the described catalyzer of claim 1, the content that it is characterized in that aluminum oxide in the described composite zeolite carrier is 15.0～40.0 heavy %.
3, according to claim 1 or 2 described catalyzer, the content that it is characterized in that Beta zeolite in the composite zeolite is 30.0～75.0 heavy %.
4, according to the described catalyzer of claim 1, the content that it is characterized in that described platinum or palladium is 0.15～0.8 heavy %.
5, according to claim 1 or 2 described catalyzer, the sodium content that it is characterized in that described mordenite and Beta zeolite is all less than 0.3 heavy %.
6, according to the described catalyzer of claim 5, the sodium content that it is characterized in that described mordenite and Beta zeolite is all less than 0.08 heavy %.
7,, it is characterized in that the silica of described mordenite and Beta zeolite is 5～80 according to claim 1 or 2 described catalyzer.
8,, it is characterized in that the silica of described mordenite and Beta zeolite is 10～60 according to the described catalyzer of claim 7.
9, the described Preparation of catalysts method of a kind of claim 1 comprises:
(1) sodium type mordenite, sodium type Beta zeolite are carried out ion-exchange with acid or ammonium salt solution and make
H-type zeolite,
(2) h-mordenite and Hydrogen Beta zeolite are mixed in proportion make composite zeolite, will answer again
It is even by the mixed of butt weight ratio 10～90: 90～10 to close zeolite and aluminum oxide, warp
Mix pinch, moulding, roasting make the composite zeolite carrier,
(3) with behind the above-mentioned composite zeolite carrier of the solution impregnation of platiniferous or palladium, dry, roasting makes catalysis
Agent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN99105790A CN1082540C (en) | 1999-04-16 | 1999-04-16 | Light hydrocarbon isomerizing catalyst and its preparation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN99105790A CN1082540C (en) | 1999-04-16 | 1999-04-16 | Light hydrocarbon isomerizing catalyst and its preparation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1270990A CN1270990A (en) | 2000-10-25 |
| CN1082540C true CN1082540C (en) | 2002-04-10 |
Family
ID=5272129
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN99105790A Expired - Lifetime CN1082540C (en) | 1999-04-16 | 1999-04-16 | Light hydrocarbon isomerizing catalyst and its preparation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1082540C (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103816934B (en) * | 2014-03-03 | 2015-09-09 | 中国石油天然气集团公司 | The C5/C6 alkane isomerization catalyst of load nickel borides and preparation and application thereof |
| CN107377869A (en) * | 2017-08-02 | 2017-11-24 | 合肥市田源精铸有限公司 | A kind of sand mulling craft for improving clay green-sand combination property |
| CN108187735B (en) * | 2017-12-30 | 2020-07-31 | 西安元创化工科技股份有限公司 | Catalyst and method for preparing high-octane gasoline by using coal-based light oil |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN87103444A (en) * | 1987-04-29 | 1988-11-30 | 环球油品公司 | Composite catalyst for paraffin isomerization |
| US5095165A (en) * | 1990-03-21 | 1992-03-10 | Mobil Oil Corporation | Hydrocarbon lubricants containing polar groups |
-
1999
- 1999-04-16 CN CN99105790A patent/CN1082540C/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN87103444A (en) * | 1987-04-29 | 1988-11-30 | 环球油品公司 | Composite catalyst for paraffin isomerization |
| US5095165A (en) * | 1990-03-21 | 1992-03-10 | Mobil Oil Corporation | Hydrocarbon lubricants containing polar groups |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1270990A (en) | 2000-10-25 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1046215C (en) | Selective hydrogen adding catalyst with metal in third main group and eighth group | |
| CN1323754C (en) | Catalyst for synthesizing dimethyl carbonate and its preparing process | |
| CN1915512A (en) | Catalyst for alkylation of toluene methanol | |
| CN1222406A (en) | Prep. of catalyst for inversion reaction of organic compound | |
| CN1098130A (en) | A kind of cracking catalyst and preparation method thereof | |
| CN103301835B (en) | Straight-chain lightweight alkane isomerization catalyst, and preparation method and application thereof | |
| CN1065261A (en) | The catalyst composition for preparing the method for a chlorotrifluoroethylene and trifluoro-ethylene and be used for this method | |
| CN1082540C (en) | Light hydrocarbon isomerizing catalyst and its preparation | |
| CN1046641C (en) | Modified zeolite catalyst for light hydrocardon aromatization reaction | |
| CN1108354C (en) | Method for hydroisomerization of light hydrocarbon | |
| CN1042201C (en) | Cracking catalyst of rich producing olefines | |
| CN1504261A (en) | Catalyst for preparing isobutene from normal butane and its preparation method and application | |
| CN1511637A (en) | Normal olefin skeleton isomerization catalyst and its preparing method | |
| CN1052290A (en) | The five-membered ring structure high-silicon zeolite that contains rare earth reaches synthetic | |
| CN1227192C (en) | Heavy arenes lightening catalyst and preparing method thereof | |
| CN1175089C (en) | Reforming catalyst containing molecular sieve | |
| JPS6190743A (en) | Catalyst composition for catalytically cracking hydrocarbon | |
| CN1884446A (en) | Hydrocracking catalyst for Tscher-Topsch synthesis of heavy wax, its preparation method and application thereof | |
| CN1114955A (en) | Catalyzer for methanation of carbon dioxide and its preparation method | |
| CN86106388A (en) | A kind of preparation method of alkane isomerization catalyst | |
| CN1228289C (en) | Process for producing adamantane compound | |
| CN1100846C (en) | Cracking catalyst and preparation method thereof | |
| CN1041387C (en) | Beta-zeolite-gamma-alumina catalyst and its preparation | |
| CN1887423A (en) | Alkyl arene isomerizing catalyst and its usage | |
| CN1286562C (en) | Normal paraffin isomerization catalyst and its preparing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C53 | Correction of patent for invention or patent application | ||
| CB02 | Change of applicant information |
Applicant after: China Petrochemical Group Corp. Applicant after: Sinopec Research Institute of Petroleum Processing Applicant before: China Petrochemical Group Corp. Applicant before: Chinese petrochemical industry Research Institute of Petro-Chemical Engineering of group company |
|
| COR | Change of bibliographic data |
Free format text: CORRECT: APPLICANT; FROM: CHINA PETROCHEMICAL CORPORATION; CHINA PETROLEUM + CHEMICAL CORPORATION, PETROLEUM CHEMICAL ENGINEERING INSTITUTE TO: CHINA PETROCHEMICAL CORPORATION; CHINA PETROCHEMICAL GROUP PETROCHEMICAL SINCE INSTITUTE |
|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20020410 |