CN106492783A - A kind of glass furnace fume SCR denitration and preparation method thereof - Google Patents
A kind of glass furnace fume SCR denitration and preparation method thereof Download PDFInfo
- Publication number
- CN106492783A CN106492783A CN201611075986.4A CN201611075986A CN106492783A CN 106492783 A CN106492783 A CN 106492783A CN 201611075986 A CN201611075986 A CN 201611075986A CN 106492783 A CN106492783 A CN 106492783A
- Authority
- CN
- China
- Prior art keywords
- glass furnace
- scr denitration
- furnace fume
- proportion
- catalyst
- 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.)
- Pending
Links
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
- B01J23/16—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
- 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
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/8621—Removing nitrogen compounds
- B01D53/8625—Nitrogen oxides
- B01D53/8628—Processes characterised by a specific catalyst
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biomedical Technology (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Health & Medical Sciences (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
Abstract
The invention discloses a kind of glass furnace fume SCR denitration and preparation method thereof, in catalyst, titanium dioxide tripoli proportion is 80 90%, active component proportion is 1 5%, and binding agent proportion is 1.5 3%, and pore creating material proportion is 1 1.5%.The formula rates such as rational carrier, active component, binding agent and pore creating material are employed, by adding specific auxiliary agent, it is ensured that the denitrating catalyst is suitable for the flue gas that glass furnace is produced in glass manufacturing process；The plastic strength and pore structure of denitration catalyst device unit are improved by adding the components such as modified binder, structural promoter and expanding agent and content, increase the forming ability of SCR denitration catalytic unit, increase active ingredient load capacity (load capacity is 1 5%), so that improve denitration efficiency.And to production technology, including the further investigation of mixing, shaping, dry, calcining and assembling etc., farthest shorten the production cycle, improve product percent of pass, improving product quality.
Description
Technical field
The present invention relates to catalyst field, specifically a kind of glass furnace fume SCR denitration and its system
Preparation Method.
Background technology
According to statistics, whole nation SO in 20102About 19,900,000 tons of discharge capacity, about 12,000,000 tons of NOx discharge, acid rain and haze etc.
Weather brings massive losses to national economy, also heavy damage environment for the survival of mankind.Nitrogen oxides heavy damage
The affinity of atmospheric ozone layer and blood red ball directly endangers the life of plant and crops more than 1000 times of CO, the acid rain of generation
Haze that is long, producing directly affects the healthy of the mankind.
The expansion utilized with solar energy composite, glass industry are rapidly developed, in Improving Glass Manufacturing Processes, glass furnace
Smoke components in, NO concentration 3200ppm, NO2Concentration 1200ppm, exhaust gas volumn 680m3/ h is special due to glass making process
Property, also contain some alkali metal oxide in its flue gas, for such high concentration nitrogen oxide and reaction temperature are again than relatively low
Flue gas, denitrating catalyst needs higher requirement in purifying smoke.
Content of the invention
It is an object of the invention to provide a kind of glass furnace fume SCR denitration and preparation method thereof, the catalysis
Agent has the advantages that low production cost, range of reaction temperature width, denitration efficiency are high.
The present invention solves technical problem and adopts the following technical scheme that：
A kind of glass furnace fume SCR denitration, including carrier, active component, binding agent and pore creating material, catalysis
In agent, titanium dioxide-montmorillonite proportion is 80-90%, and active component proportion is 1-5%, and binding agent proportion is
1.5-3%, pore creating material proportion are 1-1.5%.
Further, the carrier is titanium dioxide-montmorillonite mixed carrier；In the mixed carrier, titanium dioxide proportion is
92%, montmorillonite proportion is 8%.
Further, the active component is that (mass ratio is 2.5 for vanadic anhydride and molybdenum trioxide:1)；The bonding
Agent is that (mass ratio is 2 for PEO and waterglass:1)；The pore creating material is HPMC.
A kind of preparation method of glass furnace fume SCR denitration, concretely comprises the following steps：
A. ammonium metavanadate is dissolved in MEA and deionized water；
B. ammonium heptamolybdate is dissolved in formation clear solution in deionized water, then is gradually added in the solution that prepare in step a,
Make cloudy solution；
C. titanium dioxide-montmorillonite and auxiliary material are mixed, then under agitation, is slowly added to the preparation of step b
Solution, makes thick white thick slurry；
D. binding agent and pore creating material are added in the white thick slurry for preparing in step c, continues to mix, obtained wet type and mix
Compound material；
E. the wet mixed material prepared in step d is processed through filter and pre-extruded machine, then old 24 hours；
F. the old good material that step e is obtained is put into vacuum-extruder and monoblock type honeybee is obtained by mould extrusion molding
Nest catalyst base substrate, vacuum be more than -0.095MPa, 15-25 DEG C of extrusion temperature；
G. the honeycomb catalyst base substrate for obtaining step f is through primary drying and redrying.The condition of primary drying is dry
Dry temperature be 25-65 DEG C, dry humidity for 20-85%, drying time be 180 hours；Redrying condition for baking temperature is
65 DEG C of constant temperature, humidity is dried for 10-50%, drying time：18 hours；
H. by drying steps after honeycomb catalyst calcined；Calcination condition is 650 DEG C of calcining heat, calcination time is
36 hours.
Compared with the prior art, the present invention has the beneficial effect that：
1st, the present invention in denitrating catalyst unit composition in addition to the host elements such as Ti, V, Si, according to exhaust gas components not
Same, add the rare earth elements such as appropriate Ce, Mo or yttrium as interpolation auxiliary agent.By the rare earth elements such as Ce, Mo or dilute
The interpolation for having metallic element changes activated centre and the denitration mechanism of air environment-friendlydenitration denitration catalyst, with the high denitration effect of acquisition device
Rate, wide active window temperature and alkaline-resisting poisoning capability.
2nd, the present invention adds PEO and waterglass as adhesive aid respectively in denitrating catalyst mix stage, by bonding
Auxiliary agent denitrating catalyst is molded and specific surface area impact strengthening the forming ability of SCR denitration, increase activity into
Part and the contact area of flue gas, improve the denitration efficiency of catalyst.
3rd, for obtaining the denitrating catalyst of high intensity, rate of good quality rate, low cost, in preparation method of the present invention, in high vacuum
The material (more than vacuum -0.095MPa, 15-25 DEG C of extrusion temperature) of extrusion molding under the conditions of degree, can improve material combination
Packing, the compressive resistance of dry qualification rate and final products is improved with this；Under conditions of low extrusion temperature, can make
Extruded material temperature is basic consistent with room temperature, it is to avoid the excessive temperature differentials of material itself and room temperature environment, causes the inside and outside of product
Cracking.Dry using steam drying and in two times, catalyst elements moisture content in dry run during catalyst body drying
Scatter and disappear uniform, substantially increase yields (of the present invention yields more than 92%) of the wet base of catalyst elements in dry run,
And shorten the production cycle.
4th, Mo thulium or yttrium are added in denitration catalyst device catalyst elements component as adding
Adding assistant；HPMC, waterglass etc. is added to improve the plasticity and intensity of denitration catalyst device catalyst elements in additive.
Specific embodiment
Explanation is further explained to technical solution of the present invention below by way of specific embodiment.
Embodiment 1.
A kind of glass furnace fume SCR denitration, including carrier, active component, binding agent and pore creating material, catalysis
In agent, titanium dioxide-montmorillonite proportion is 80%, and active component proportion is 3%, and binding agent proportion is 2%, makes
Agent proportion in hole is 1.1%.
Above-mentioned carrier adopts titanium dioxide-tripoli mixed carrier, and in mixed carrier, titanium dioxide proportion is 92%, montmorillonite proportion
8%；
Above-mentioned active component is vanadic anhydride and molybdenum trioxide, and mass ratio is 2.5:1；
Above-mentioned binding agent is PEO and waterglass, and mass ratio is 2:1；
Above-mentioned pore creating material is HPMC.
Embodiment 2
A kind of glass furnace fume SCR denitration, including carrier, active component, binding agent and pore creating material, its
In, in catalyst, titanium dioxide-montmorillonite proportion is 90%, and active component proportion is 4.5%, binding agent proportion
For 1.5%, pore creating material proportion is 1.5%.The other the same as in Example 1.
Embodiment 3
Above-described embodiment 1 and the preparation method of 2 denox catalysts, including：Dispensing, mixing, filtration pre-extruded, extrusion, I levels are done
Dry, II levels are dried, are calcined, assembling, packaging and storage, are concretely comprised the following steps：
A. ammonium metavanadate is dissolved in MEA and deionized water；
B. ammonium heptamolybdate is dissolved in formation clear solution in deionized water, then is gradually added in the solution that prepare in step a,
Make cloudy solution；
C. titanium dioxide-montmorillonite and auxiliary material are mixed, then under agitation, is slowly added to the preparation of step b
Solution, makes thick white thick slurry；
D. binding agent and pore creating material are added in the white thick slurry for preparing in step c, continues to mix, obtained wet type and mix
Compound material；
E. the wet mixed material prepared in step d is processed through filter and pre-extruded machine, then old 24 hours；
F. the old good material that step e is obtained is put into vacuum-extruder and monoblock type honeybee is obtained by mould extrusion molding
Nest catalyst base substrate, vacuum be more than -0.095MPa, 15-25 DEG C of extrusion temperature；
G. the honeycomb catalyst base substrate for obtaining step f is through primary drying and redrying.The condition of primary drying is dry
Dry temperature be 25-65 DEG C, dry humidity for 20-85%, drying time be 180 hours；Redrying condition for baking temperature is
65 DEG C of constant temperature, humidity is dried for 10-50%, drying time：18 hours；
H. by drying steps after honeycomb catalyst calcined；Calcination condition is calcining heat：650 DEG C, calcination time
For 36 hours.
I. after the completion of drying, catalyst base is admitted to tunnel cave and is fired, and finished product is cut and packaging gets product.
Preferably, the present invention is dried, drying interior edge
The built-in row taper blower fan in axis direction, blower fan arranges multiple air outlets from top to bottom, and air outlet direction is differed, and makes drying
Indoor formation cross-ventilation, it is ensured that catalyst elements moisture content scatters and disappears uniformly in dry run, substantially increases catalyst elements wet
Yields of the base in dry run, shortens the production cycle.
By taking 2 denitrating catalyst of embodiment as an example, the catalyst prod for preparing gained by 3 method of embodiment is surveyed by pressure
To the compressive resistance of catalyst elements, test-run a machine detects that testing result is as shown in table 1.
The plasticity and intensity contrast of 1. denitrating catalyst unit of table
| Laterally resistance to compression (MPa) | Longitudinal resistance to compression (MPa) | |
| Design load | ≥0.6 | ≥2.0 |
| Measured value | 1.29 | 3.5 |
Denitration catalyst device catalyst elements denitration performance is evaluated by flue gas evaluating apparatus and flue gas analyzer,
The catalysis activity of catalyst, sulphur conversion ratio, the escaping of ammonia, stability etc. are investigated emphatically.
Catalyst activity is tested with pilot plant test facility, it is desirable to denitration efficiency >=80%, the escaping of ammonia rate≤3ppmvdc,
SO2/SO3Conversion ratio≤1.00%, pressure drop≤450Pa, flue gas condition of the test condition according to owner.
Measured result is：Denitration efficiency >=90%, the escaping of ammonia rate≤2.5ppmvdc, SO2/SO3Conversion ratio≤0.9%, pressure
Drop≤400Pa.
By specific surface of the equipment such as physical absorption, pressure testing machine, wear-resistant device, fluorescence analyser to catalyst elements
Product, compressive resistance, wear-resisting intensity, material composition carry out microcosmic detection.As Table 2,3.
The specific surface area of 2. catalyst elements of table, compressive resistance, wear-resisting intensity contrast
3. glass furnace catalyst component testing result of table
Different catalyst raw materials carries out being sufficiently mixed stirring, then mixes the solid material being well mixed and liquid charging stock
Close stirring uniformly slurry.The raw material slurry for stirring enters double-deck pre-filtering extruder and is fully kneaded, and is pressed
Make raw material base of uniform size.There is raw material base input the vacuum-extruder of high torque and high mixing helical structure, vacuum to squeeze
Go out machine and raw material base is squeezed into catalyst base by the aperture, pitch being previously set.Steam one-level is dried, steam secondary drying,
After the completion of drying, catalyst base is admitted to tunnel cave and is fired, and finished product is cut and is packed.The denitration catalyst device of the present invention
The plasticity and intensity of catalyst elements can be improved.
Claims (8)
1. a kind of glass furnace fume SCR denitration, it is characterised in that the catalyst composition is as follows：
Carrier 80-90%,
Active component 1-5%,
Binding agent 1.5-3%,
Pore creating material 1-1.5%.
2. a kind of glass furnace fume SCR denitration according to claim 1, it is characterised in that the carrier
For titanium dioxide-montmorillonite mixed carrier.
3. a kind of glass furnace fume SCR denitration carrier according to claim 2, it is characterised in that described
In mixed carrier, titanium dioxide proportion is 92%, and montmorillonite proportion is 8%.
4. a kind of glass furnace fume SCR denitration according to claim 1, it is characterised in that the activity
Composition is vanadic anhydride (V2O5) and molybdenum trioxide (WO3), vanadic anhydride, the mass ratio of molybdenum oxide are 2.5:1.
5. a kind of glass furnace fume SCR denitration according to claim 1, it is characterised in that the bonding
Agent is 2 for the mass ratio of PEO (PEO) and waterglass, PEO and waterglass:1.
6. a kind of glass furnace fume SCR denitration according to claim 1, it is characterised in that the pore-creating
Agent is hydroxypropyl methyl cellulose (HPMC).
7. a kind of preparation method of glass furnace fume SCR denitration, it is characterised in that comprise the following steps：
A. ammonium metavanadate is dissolved in MEA and water；
B. by formation clear solution soluble in water for ammonium heptamolybdate, then it is gradually added in the solution that prepare in step a, makes cotton-shaped molten
Liquid；
C. titanium dioxide-montmorillonite and auxiliary material are mixed, then under agitation, are slowly added to the solution of step b preparation,
Make thick white thick slurry；
D. binding agent and pore creating material are added in the white thick slurry for preparing in step c, is continued to mix, is obtained wet mixed thing
Material；
E. the wet mixed material prepared in step d is processed through filter and pre-extruded machine, then old 12-24 hours；
F. the old good material that step e is obtained is put into vacuum-extruder integral honeycomb is obtained by mould extrusion molding and urged
Agent base substrate；
G. the honeycomb catalyst base substrate for obtaining step f is dried through twice；
H. by drying steps after honeycomb catalyst calcined, calcining heat be 650 DEG C, calcination time be 30-55 hours.
8. the preparation method of a kind of glass furnace fume SCR denitration according to claim 7, its feature exist
In the drying twice in step g includes primary drying and redrying.The condition of primary drying be baking temperature be 25-65 DEG C,
It is 150-300 hours that humidity is dried for 20-85%, drying time；Redrying condition is that baking temperature is 65 DEG C of constant temperature, dries
Humidity is 10-50%, drying time：12-20 hours.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611075986.4A CN106492783A (en) | 2016-11-30 | 2016-11-30 | A kind of glass furnace fume SCR denitration and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201611075986.4A CN106492783A (en) | 2016-11-30 | 2016-11-30 | A kind of glass furnace fume SCR denitration and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN106492783A true CN106492783A (en) | 2017-03-15 |
Family
ID=58329125
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201611075986.4A Pending CN106492783A (en) | 2016-11-30 | 2016-11-30 | A kind of glass furnace fume SCR denitration and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106492783A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109012689A (en) * | 2018-08-23 | 2018-12-18 | 攀钢集团攀枝花钢铁研究院有限公司 | A kind of denitrating catalyst and preparation method thereof |
| CN113600179A (en) * | 2021-09-16 | 2021-11-05 | 山东博霖环保科技发展有限公司 | Denitration catalyst and preparation method thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101371970A (en) * | 2008-09-15 | 2009-02-25 | 江苏中科节能环保技术有限公司 | Catalyst and preparation method thereof suitable for denitration of flue gas containing alkali metal oxide |
| CN103191722A (en) * | 2013-04-23 | 2013-07-10 | 江苏龙源催化剂有限公司 | Crosslinked montmorillonite honeycomb type denitration catalyst and preparation method thereof |
| CN103252231A (en) * | 2013-05-02 | 2013-08-21 | 易能(中国)环保科技有限公司 | Denitration catalyst and preparation method thereof |
| CN103495413A (en) * | 2013-09-23 | 2014-01-08 | 宜兴市宜刚环保工程材料有限公司 | Low-cost denitration catalyst and preparation process thereof |
| CN104209117A (en) * | 2014-09-16 | 2014-12-17 | 东营信拓汽车消声器有限公司 | Preparation method of high-strength and antioxidant rare-earth-based smoke denitration catalyst |
| CN105148933A (en) * | 2015-08-20 | 2015-12-16 | 天河（保定）环境工程有限公司 | Denitration catalyst for glass kiln and preparation method of denitration catalyst |
-
2016
- 2016-11-30 CN CN201611075986.4A patent/CN106492783A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101371970A (en) * | 2008-09-15 | 2009-02-25 | 江苏中科节能环保技术有限公司 | Catalyst and preparation method thereof suitable for denitration of flue gas containing alkali metal oxide |
| CN103191722A (en) * | 2013-04-23 | 2013-07-10 | 江苏龙源催化剂有限公司 | Crosslinked montmorillonite honeycomb type denitration catalyst and preparation method thereof |
| CN103252231A (en) * | 2013-05-02 | 2013-08-21 | 易能(中国)环保科技有限公司 | Denitration catalyst and preparation method thereof |
| CN103495413A (en) * | 2013-09-23 | 2014-01-08 | 宜兴市宜刚环保工程材料有限公司 | Low-cost denitration catalyst and preparation process thereof |
| CN104209117A (en) * | 2014-09-16 | 2014-12-17 | 东营信拓汽车消声器有限公司 | Preparation method of high-strength and antioxidant rare-earth-based smoke denitration catalyst |
| CN105148933A (en) * | 2015-08-20 | 2015-12-16 | 天河（保定）环境工程有限公司 | Denitration catalyst for glass kiln and preparation method of denitration catalyst |
Non-Patent Citations (1)
| Title |
|---|
| 张开编著: "《高分子界面化学》", 31 March 1997, 中国石化出版社 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109012689A (en) * | 2018-08-23 | 2018-12-18 | 攀钢集团攀枝花钢铁研究院有限公司 | A kind of denitrating catalyst and preparation method thereof |
| CN109012689B (en) * | 2018-08-23 | 2021-06-29 | 攀钢集团攀枝花钢铁研究院有限公司 | Denitration catalyst and preparation method thereof |
| CN113600179A (en) * | 2021-09-16 | 2021-11-05 | 山东博霖环保科技发展有限公司 | Denitration catalyst and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106540683B (en) | The preparation method of wear-resistant SCR catalyst | |
| CN104475122A (en) | Forming SCR catalyst with both water resistance and sulphur resistance and preparation method thereof | |
| CN106975493A (en) | A kind of honeycomb catalyst materials and its forming method | |
| CN101428212B (en) | Selective catalysis reduction denitrate catalyst for composite carrier flue gas and preparation method thereof | |
| CN105170136A (en) | High specific surface area honeycomb type denitration catalyst and preparation method thereof | |
| CN111036187B (en) | Honeycomb carrier and preparation method and application thereof | |
| CN101513620A (en) | Preparation method for titanium dioxide group catalyst carrier | |
| CN107362808A (en) | Integrated low temperature denitrating catalyst and preparation method thereof | |
| CN110639504A (en) | Honeycomb type low-temperature flue gas denitration catalyst and preparation method thereof | |
| CN106140150A (en) | A kind of honeycomb fashion cerium zirconium manganese titanio denitrating catalyst and preparation method thereof | |
| CN110639501A (en) | SCR denitration catalyst and preparation method thereof | |
| CN106268786A (en) | A kind of low-temperature denitration catalyst and preparation method thereof | |
| CN112973668A (en) | High-strength honeycomb type low-temperature SCR denitration catalyst and preparation method thereof | |
| CN106492783A (en) | A kind of glass furnace fume SCR denitration and preparation method thereof | |
| CN107335427A (en) | The preparation method of the porous SCR denitration of Gas Generator Set low temperature | |
| CN107754810A (en) | A kind of wide temperature smoke denitrating catalyst of non-vanadium base monolithic, preparation method and application | |
| CN113499783A (en) | Preparation method of ultralow-temperature SCR denitration catalyst | |
| CN110694640B (en) | Water-resistant sulfur-resistant denitration catalyst and preparation method thereof | |
| CN106902807A (en) | A kind of particle type low-temperature SCR catalyst and preparation method thereof | |
| JP2580239B2 (en) | Method for producing gas parallel flow type sulfurous acid gas oxidation catalyst | |
| CN1342601A (en) | Process for preparing V catalyst used to prepare low-temp sulfuric acid | |
| CN108126692A (en) | Good automobile-used extruded type SCR denitration of a kind of low temperature active and preparation method thereof | |
| CN102527373A (en) | Selective catalytic reduction (SCR) denitration catalyst with TiO2 as carrier | |
| CN106902878A (en) | It is a kind of for gasoline, coal tar hydrorefining desulfurization, the catalyst of denitrogenation and preparation method thereof | |
| CN109772430A (en) | A kind of molding denitrating catalyst of the wide temperature of high-strength light |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20170315 |
|
| RJ01 | Rejection of invention patent application after publication |