WO2010130772A1 - Removal of contaminant materials from a process stream - Google Patents

Removal of contaminant materials from a process stream Download PDF

Info

Publication number
WO2010130772A1
WO2010130772A1 PCT/EP2010/056528 EP2010056528W WO2010130772A1 WO 2010130772 A1 WO2010130772 A1 WO 2010130772A1 EP 2010056528 W EP2010056528 W EP 2010056528W WO 2010130772 A1 WO2010130772 A1 WO 2010130772A1
Authority
WO
WIPO (PCT)
Prior art keywords
copper
cerium
support
catalyst
zirconium
Prior art date
Application number
PCT/EP2010/056528
Other languages
French (fr)
Inventor
Geert Marten Bakker
Nicholas Caiulo
Hendrik Albertus Colijn
Bob Scheffer
Original Assignee
Shell Internationale Research Maatschappij B.V.
Steur, Chantal
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Shell Internationale Research Maatschappij B.V., Steur, Chantal filed Critical Shell Internationale Research Maatschappij B.V.
Publication of WO2010130772A1 publication Critical patent/WO2010130772A1/en

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
    • B01J23/002—Mixed oxides other than spinels, e.g. perovskite
    • 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
    • B01D53/864—Removing carbon monoxide or hydrocarbons
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/83—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with rare earths or actinides
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/024—Multiple impregnation or coating
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G11/00—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
    • C10G11/02—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils characterised by the catalyst used
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/10—Noble metals or compounds thereof
    • B01D2255/104—Silver
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/206—Rare earth metals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/207—Transition metals
    • B01D2255/20746—Cobalt
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/207—Transition metals
    • B01D2255/20753—Nickel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/207—Transition metals
    • B01D2255/20761—Copper
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/20—Metals or compounds thereof
    • B01D2255/209—Other metals
    • B01D2255/2092—Aluminium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2255/00—Catalysts
    • B01D2255/40—Mixed oxides
    • B01D2255/407—Zr-Ce mixed oxides
    • 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
    • B01J23/38—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals
    • B01J23/54—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of noble metals combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/66—Silver or gold
    • 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
    • B01J2523/00—Constitutive chemical elements of heterogeneous catalysts
    • 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
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/40—Catalysts, in general, characterised by their form or physical properties characterised by dimensions, e.g. grain size
    • 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
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/50—Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
    • 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
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/61—Surface area
    • B01J35/613—10-100 m2/g
    • 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
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/61—Surface area
    • B01J35/615—100-500 m2/g
    • 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
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/63—Pore volume
    • B01J35/635—0.5-1.0 ml/g
    • 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
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/02—Impregnation, coating or precipitation
    • B01J37/0201—Impregnation
    • B01J37/0203—Impregnation the impregnation liquid containing organic compounds

Definitions

  • the present invention relates to a process for the removal of combustible volatile contaminant materials from a process stream and a catalyst for use therein.
  • Volatile contaminants are often produced by industrial chemical processes. Such contaminants are often vented to the atmosphere but with increasing environmental legislation, the amount of such contaminants that are permitted to be vented from commercial manufacturing plants is being cut back.
  • One such area in which contamination in vent or waste gas can occur is in the production of ethylene oxide.
  • the residual gases that remain after recovery of the bulk ethylene oxide product, are recycled to the ethylene oxidation reactor.
  • a small bleed stream is withdrawn from the recycled gases to prevent build-up of impurities such as argon, ethane and nitrogen in the recycle gas loop.
  • a side stream, part or all of the recycle gas, is usually scrubbed with an aqueous CO 2 absorbent for removal of excess CO 2 which is subsequently stripped from the absorbent and may be vented, or preferably is recovered for use or sale as a by-product.
  • Such contaminants may be organic hydrocarbons, such as ethylene, methane, ethylene oxide, and halogen-containing compounds.
  • the contaminant is a volatile organic compound
  • current removal processes utilise thermal or catalytic decomposition, preferably via combustion.
  • the vent gases are cleaned of these impurities in an oxidiser by total combustion in a packed bed reactor, often catalytically.
  • a reactor is combined with a heat exchanger in order to recover the combustion heat generated.
  • combustion, or incineration can for example occur within a catalytic incinerator whereby one or more catalyst beds are heated to high temperatures (in the range of from approximately 300 0 C to 800 0 C, typically 500 0 C) and operate at atmospheric pressure.
  • Various heat exchange mechanisms are incorporated to minimise energy loss and improve efficiency but often they cannot constantly control the process to avoid the occurrence of hot spots or temperature flux through the catalyst bed where a sudden increase in temperature to the upper level of the reactor design range.
  • the catalysts utilized in such catalytic combustion units comprise a noble metal of the platinum group, for example platinum, palladium, or rhenium, on a porous inorganic support, such as alumina.
  • a noble metal of the platinum group for example platinum, palladium, or rhenium
  • Such catalysts have a good activity in catalytic combustion but have the problem that they are adversely affected by high temperatures in the range of from 450 to 800 °C. At such temperatures the catalyst declines in activity and either shows erratic, unstable performance or at the worst fails completely requiring an earlier change of catalyst than planned for.
  • Such sensitivity to high temperatures means that strict control of the temperature in the process streams must be maintained, leading to extra controls and energy requirements in the process to be carried out. Reduction in the temperature of the process stream may be achieved, for example, by venting heat and, thus, wasting energy.
  • Copper has been utilized in incineration or combustion units as a preferred metal for combustion tubes. Copper is also utilized in catalyst compositions for a variety of processes ranging from hydrogenation (see EP-A-1737569) to DeNOx applications (see M. Ozawa, Journal of Alloys and Compounds, 2000, 408-412, 1090- 1095) . However, it is has not heretofore been proposed for use in catalytic combustion processes particularly for methane and ethylene because it is perceived as a low activity catalytic metal in comparison to the precious metals of the conventional catalysts.
  • the present invention provides a process for the removal of combustible volatile contaminant materials from a first process stream, which comprises combusting the volatile materials in the presence of a catalyst composition which comprises a support comprising gamma- alumina; a first metal component which comprises one or more metals selected from the group consisting of copper, nickel, cobalt, and silver; and optionally a second metal component which comprises one or more metals selected from the group consisting of lanthanum, cerium, and zirconium to form a cleaned stream, which also contains combustion products.
  • a catalyst composition which comprises a support comprising gamma- alumina; a first metal component which comprises one or more metals selected from the group consisting of copper, nickel, cobalt, and silver; and optionally a second metal component which comprises one or more metals selected from the group consisting of lanthanum, cerium, and zirconium to form a cleaned stream, which also contains combustion products.
  • the present invention also provides a catalyst composition which comprises a copper component, a cerium component and a zirconium component on a support comprising gamma-alumina.
  • the present invention provides a process for producing said catalyst composition, wherein in a first impregnation step the support comprising gamma- alumina is impregnated with the cerium and zirconium components to form a first impregnated support; the first impregnated support is then calcined at a temperature in the range of from 300 to 850 °C to form a calcined first impregnated support; and then in a second impregnation step the calcined first impregnated support is impregnated with the copper component to form a second impregnated support and then the second impregnated support is calcined at a temperature in the range of from 300 to 700°C.
  • Figure 1 shows the conversion of methane at different temperatures for different catalysts in the Examples .
  • Figure 2 shows the catalyst stability at high temperatures for the catalysts of the Examples.
  • Figure 3 shows the catalyst stability at high levels of water vapour for the catalysts of the Examples.
  • a metal component selected from the group consisting of copper, nickel, cobalt and silver in place of a noble metal of the platinum group has yielded a catalyst and a process for the removal of combustible volatile contaminant materials from a process stream that are highly stable and are not susceptible to temperature flux or hot spots, nor, for preferred embodiments, to water vapour.
  • the catalyst and process are also tolerant to the presence of sulfur species, such as H 2 S and SO 2 .
  • the catalyst also preferably contains one or more metals selected from the group consisting of lanthanum, cerium and zirconium, and is also based on a gamma-alumina support.
  • the process of the present invention is intended to remove combustible volatile contaminant materials from a first process stream.
  • the first process stream is suitably an effluent stream from a chemical plant.
  • it comprises the CO 2 _rich effluent stream from the CO 2 absorber of an ethylene oxide chemical plant.
  • contaminant materials refers to materials present in the process stream each at levels of no more than 3% by volume.
  • the contaminant materials are present each at levels of no more than 2% by volume, more preferably no more than 1% by volume, even more preferably no more than 5000 ppmv, even more preferably no more than 4000 ppmv, most preferably no more than 3000 ppmv.
  • ⁇ contaminant materials' used herein refers to any combustible volatile material intended to be removed from the process stream.
  • such materials comprise organic hydrocarbons, carbon monoxide and/or nitrogen oxides (NO x ) . More preferably, said organic hydrocarbons include methane, ethylene, ethylene oxide and halogen-containing compounds.
  • organic hydrocarbons include methane, ethylene, ethylene oxide and halogen-containing compounds.
  • other combustible volatile material present at levels of no more than 3 % by volume may also be removed by the process of the present invention.
  • Such material includes any combustible volatile material fed into or produced in a chemical plant.
  • the catalyst composition comprises a support comprising gamma-alumina.
  • the support may be any suitable shape including those with circular cross-sections (e.g. rings) and non- circular cross-sections. Suitable shapes with non- circular cross-sections include, but are not limited to, tri-lobed, spiral-grooved, votex-profiled and tetra-lobed forms.
  • the support comprising gamma-alumina is in the form of a ring.
  • the support suitably has a diameter in the range of from 0.5 to 15 mm, preferably in the range of from 1 to 10 mm.
  • diameter refers to the diameter of the smallest circle within which the particle cross- section would fit.
  • the surface area of a catalyst is measured according to the Brunauer, Emmett and Teller
  • the surface area of the catalyst is in the range of from 50 to 250 m 2 /g.
  • pore volume is measured by mercury intrusion porosimetry according to DIN 6613.
  • the total pore volume of the catalyst is preferably at least 0.30 cm 3 /g.
  • the total pore volume of the catalyst is at most 0.80 cm 3 /g.
  • the first metal component comprises one or more metals selected from the group consisting of copper, nickel, cobalt, and silver.
  • the first metal component is copper.
  • Said first metal component is present in amount of at least 0.1 wt%, preferably at least 1 %, more preferably at least 2 wt% based on the total weight of the finished catalyst.
  • the first metal component is present in amount of at most 20 wt%, preferably at most 15 wt%, more preferably at most 10wt% based on the total weight of the finished catalyst.
  • the second metal component when present, is suitably present in an amount of at least 0.01 wt%, preferably at least 0.1 wt%, more preferably at least 1 wt%, even more preferably at least 1.5 wt% based on the total weight of the finished catalyst.
  • the second metal component is suitably present in an amount of at most 20 wt%, preferably at most 15 wt%, more preferably at most 12 wt%, based on the total weight of the finished catalyst .
  • the second metal component comprises cerium and zirconium.
  • both the cerium and the zirconium are present individually in an amount of at least 0.01 wt%, preferably at least 0.1 wt%, more preferably at least 0.5 wt%, most preferably at least 1 wt% based on the total weight of the finished catalyst.
  • the cerium and the zirconium are present individually in an amount of at most 10 wt%, preferably at most 8 wt%, more preferably at most 6 wt%, based on the total weight of the finished catalyst.
  • the zirconium and cerium are present such that the ratio of zirconium to cerium (with respect to the mass of each metal present) is at least 1:1, preferably at least 1.5:1, more preferably at least 2:1.
  • the zirconium and cerium are present such that the ratio of zirconium to cerium is no more than 5:1, preferably no more than 4:1.
  • the process of the present invention is suitably carried out at a temperature in the range of from 400 to 800 0 C, preferably in the range of from 500 to 700 0 C.
  • the process of the present invention may be carried out as a batch or a continuous process. However, the process is most preferably carried out in a continuous manner .
  • the preferred catalyst composition of the present invention is suitably prepared by a process comprising the steps of (i) impregnating the alumina support, in a first impregnation step, with the cerium and zirconium components to form a first impregnated support; (ii) calcining the first impregnated support at a temperature in the range of from 300 to 850 °C to form a calcined first impregnated support; (iii) impregnating, in a second impregnation step, the calcined first impregnated support with the copper component to form a second impregnated support; and (iv) then calcining the second impregnated support at a temperature in the range of from 300 to 700°C.
  • the first impregnation step may be carried out by any suitable impregnation process. However, an incipient wetness impregnation method is preferred.
  • the cerium and zirconium may be impregnated onto the alumina support either as separate aqueous solutions of cerium and zirconium salts or in a single impregnation solution comprising both cerium and zirconium salts.
  • the cerium and zirconium are impregnated onto the alumina support in a single impregnation solution comprising both cerium and zirconium salts.
  • Preferred cerium and zirconium salts are nitrates.
  • the first impregnated support is dried. Any usual method of drying may be used. A preferred method is rotary drying.
  • the first impregnated support is calcined at a temperature in the range of from 300 to 850 0 C, preferably in the range of from 500 to 700 0 C.
  • the second impregnation step may also be carried out by any suitable impregnation process. Again, an incipient wetness impregnation method is preferred.
  • the second impregnation step involves the impregnation of the calcined first impregnated support with an aqueous solution comprising the copper component in the form of copper nitrate or copper citrate.
  • the second impregnated support is calcined at a temperature in the range of from 300 to 700 0 C, preferably in the range of from 400 to 600 0 C.
  • catalysts were prepared according to the following general procedure. For contents and amounts, see Table 1.
  • the catalysts were produced using a two-step incipient wetness impregnation method (95% pore volume).
  • a high surface area gamma-alumina support (ex-Norpro) was firstly impregnated with an aqueous solution of cerium, lathanum or cerium/zirconium nitrate.
  • the impregnated support was then dried by rotary drying at 80 0 C and calcined at 500 0 C using a heating profile of 2 0 C per minute.
  • the first impregnation, drying and calcination steps were omitted.
  • the catalysts were impregnated with an aqueous solution of either copper nitrate or citrate.
  • the impregnated supports were then dried by rotary drying at 80 0 C and then calcined at 600 0 C using a heating profile of 2 0 C per minute. Table 1
  • ⁇ catalyst 6' a catalyst consisting of a rhodium-cerium phase catalyst supported on 8.0 mm alpha alumina rings, which is termed ⁇ catalyst 6' herein.
  • Figure 1 shows a reduction in activity of approximately 50 0 C for the copper-based catalysts of the present invention compared to the rhodium-based catalyst.
  • this is actually a benefit of the present invention as, in practice, the process stream to be treated is usually already at this higher temperature and, thus, the process of the present invention can be carried out without the need for venting heat, an adaptation which is usually required in order to protect a rhodium/cerium-based catalyst, such as catalyst 6.
  • Catalyst 6 in terms of stability with respect to high temperatures. After 150 hours on stream and 4 high temperature excursions, catalyst 6 lost approximately 80 0 C in activity in comparison to an average of approximately 15 0 C for catalysts 1 to 5. It is interesting to note that this loss in activity for catalysts 1 to 5 was only observed after the first temperature ramp, after subsequent temperature ramps little or no loss in activity was observed. Catalysts 1, 2, 4, 5, 7 and 8 were then tested under conditions to create/stimulate the aging of the catalyst.
  • Catalyst 9 was produced using a two-step incipient wetness impregnation method (95% pore volume) .
  • a high surface area gamma-alumina support (ex-Norpro) was firstly impregnated with an aqueous solution of cerium nitrate and zirconium nitrate. The impregnated support was then dried by rotary drying at 120 0 C and calcined at 500 0 C using a heating profile of 2 0 C per minute. After cooling, the catalysts were impregnated with an aqueous solution of either copper nitrate. The impregnated supports were then dried by rotary drying at 120 0 C and then calcined at 600 0 C using a heating profile of 2 0 C per minute.
  • the catalyst properties are as follows:

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • General Chemical & Material Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Analytical Chemistry (AREA)
  • Catalysts (AREA)

Abstract

The invention provides a process for the removal of combustible volatile contaminant materials from a first process stream, which comprises combusting the volatile materials in the presence of a catalyst composition which comprises a support comprising gamma-alumina; a first 5 metal component which comprises one or more metals selected from the group consisting of copper, nickel, cobalt, and silver; and optionally a second metal component which comprises one or more metals selected from the group consisting of lanthanum, cerium, and 10 zirconium to form a cleaned stream, which also contains combustion products.

Description

REMOVAL OF CONTAMINANT MATERIALS FROM A PROCESS STREAM
Field of the Invention
The present invention relates to a process for the removal of combustible volatile contaminant materials from a process stream and a catalyst for use therein. Background of the Invention
Volatile contaminants are often produced by industrial chemical processes. Such contaminants are often vented to the atmosphere but with increasing environmental legislation, the amount of such contaminants that are permitted to be vented from commercial manufacturing plants is being cut back.
One such area in which contamination in vent or waste gas can occur is in the production of ethylene oxide. The residual gases that remain after recovery of the bulk ethylene oxide product, are recycled to the ethylene oxidation reactor. Customarily, a small bleed stream is withdrawn from the recycled gases to prevent build-up of impurities such as argon, ethane and nitrogen in the recycle gas loop. A side stream, part or all of the recycle gas, is usually scrubbed with an aqueous CO2 absorbent for removal of excess CO2 which is subsequently stripped from the absorbent and may be vented, or preferably is recovered for use or sale as a by-product. A problem arises particularly in manufacturing plants of large capacity in that during scrubbing of the recycle gas side stream, small amounts of hydrocarbon are dissolved and/or entrained in the CO2 absorbent and need to be removed to avoid contamination of the carbon dioxide.
Various systems have been proposed for the removal of volatile contaminants from vent gases. Such contaminants may be organic hydrocarbons, such as ethylene, methane, ethylene oxide, and halogen-containing compounds. Where the contaminant is a volatile organic compound, current removal processes utilise thermal or catalytic decomposition, preferably via combustion.
Thus in many industrial processes the vent gases are cleaned of these impurities in an oxidiser by total combustion in a packed bed reactor, often catalytically. In some instances, such a reactor is combined with a heat exchanger in order to recover the combustion heat generated. Such combustion, or incineration, can for example occur within a catalytic incinerator whereby one or more catalyst beds are heated to high temperatures (in the range of from approximately 3000C to 8000C, typically 500 0C) and operate at atmospheric pressure. Various heat exchange mechanisms are incorporated to minimise energy loss and improve efficiency but often they cannot constantly control the process to avoid the occurrence of hot spots or temperature flux through the catalyst bed where a sudden increase in temperature to the upper level of the reactor design range. Generally the catalysts utilized in such catalytic combustion units comprise a noble metal of the platinum group, for example platinum, palladium, or rhenium, on a porous inorganic support, such as alumina. Such catalysts have a good activity in catalytic combustion but have the problem that they are adversely affected by high temperatures in the range of from 450 to 800 °C. At such temperatures the catalyst declines in activity and either shows erratic, unstable performance or at the worst fails completely requiring an earlier change of catalyst than planned for.
Such sensitivity to high temperatures means that strict control of the temperature in the process streams must be maintained, leading to extra controls and energy requirements in the process to be carried out. Reduction in the temperature of the process stream may be achieved, for example, by venting heat and, thus, wasting energy.
Another difficulty with catalysts in such combustion units is that when methane is the contaminant, combustion yields water as a combustion product. The conventional combustion catalysts are also adversely affected by a high water vapour and this again cause the failure of the catalyst to perform stably or at all.
It has been proposed to include a rare earth promoter into such conventional catalysts to enhance stability but this has not overcome these problems adequately.
Copper has been utilized in incineration or combustion units as a preferred metal for combustion tubes. Copper is also utilized in catalyst compositions for a variety of processes ranging from hydrogenation (see EP-A-1737569) to DeNOx applications (see M. Ozawa, Journal of Alloys and Compounds, 2000, 408-412, 1090- 1095) . However, it is has not heretofore been proposed for use in catalytic combustion processes particularly for methane and ethylene because it is perceived as a low activity catalytic metal in comparison to the precious metals of the conventional catalysts. Summary of the Invention The present invention provides a process for the removal of combustible volatile contaminant materials from a first process stream, which comprises combusting the volatile materials in the presence of a catalyst composition which comprises a support comprising gamma- alumina; a first metal component which comprises one or more metals selected from the group consisting of copper, nickel, cobalt, and silver; and optionally a second metal component which comprises one or more metals selected from the group consisting of lanthanum, cerium, and zirconium to form a cleaned stream, which also contains combustion products.
The present invention also provides a catalyst composition which comprises a copper component, a cerium component and a zirconium component on a support comprising gamma-alumina.
Further, the present invention provides a process for producing said catalyst composition, wherein in a first impregnation step the support comprising gamma- alumina is impregnated with the cerium and zirconium components to form a first impregnated support; the first impregnated support is then calcined at a temperature in the range of from 300 to 850 °C to form a calcined first impregnated support; and then in a second impregnation step the calcined first impregnated support is impregnated with the copper component to form a second impregnated support and then the second impregnated support is calcined at a temperature in the range of from 300 to 700°C. Brief Description of the Drawings
Figure 1 shows the conversion of methane at different temperatures for different catalysts in the Examples .
Figure 2 shows the catalyst stability at high temperatures for the catalysts of the Examples.
Figure 3 shows the catalyst stability at high levels of water vapour for the catalysts of the Examples. Detailed Description of the Invention
We have now found that the inclusion of a metal component selected from the group consisting of copper, nickel, cobalt and silver in place of a noble metal of the platinum group has yielded a catalyst and a process for the removal of combustible volatile contaminant materials from a process stream that are highly stable and are not susceptible to temperature flux or hot spots, nor, for preferred embodiments, to water vapour. In preferred embodiments, the catalyst and process are also tolerant to the presence of sulfur species, such as H2S and SO2. As well as the metal component selected from the group consisting of copper, nickel, cobalt and silver, the catalyst also preferably contains one or more metals selected from the group consisting of lanthanum, cerium and zirconium, and is also based on a gamma-alumina support.
The process of the present invention is intended to remove combustible volatile contaminant materials from a first process stream.
The first process stream is suitably an effluent stream from a chemical plant. In one preferred embodiment of the present invention, it comprises the CO2_rich effluent stream from the CO2 absorber of an ethylene oxide chemical plant.
As used herein, contaminant materials refers to materials present in the process stream each at levels of no more than 3% by volume. Preferably, the contaminant materials are present each at levels of no more than 2% by volume, more preferably no more than 1% by volume, even more preferably no more than 5000 ppmv, even more preferably no more than 4000 ppmv, most preferably no more than 3000 ppmv.
The term ^contaminant materials' used herein refers to any combustible volatile material intended to be removed from the process stream. Preferably, such materials comprise organic hydrocarbons, carbon monoxide and/or nitrogen oxides (NOx) . More preferably, said organic hydrocarbons include methane, ethylene, ethylene oxide and halogen-containing compounds. However, other combustible volatile material present at levels of no more than 3 % by volume may also be removed by the process of the present invention. Such material includes any combustible volatile material fed into or produced in a chemical plant.
The catalyst composition comprises a support comprising gamma-alumina.
The support may be any suitable shape including those with circular cross-sections (e.g. rings) and non- circular cross-sections. Suitable shapes with non- circular cross-sections include, but are not limited to, tri-lobed, spiral-grooved, votex-profiled and tetra-lobed forms. Preferably, the support comprising gamma-alumina is in the form of a ring.
The support suitably has a diameter in the range of from 0.5 to 15 mm, preferably in the range of from 1 to 10 mm. When referring to particles with non-circular cross-sections, the term diameter refers to the diameter of the smallest circle within which the particle cross- section would fit.
As used herein, the surface area of a catalyst is measured according to the Brunauer, Emmett and Teller
(BET) method. Preferably the surface area of the catalyst is in the range of from 50 to 250 m2/g.
As used herein, pore volume is measured by mercury intrusion porosimetry according to DIN 6613. The total pore volume of the catalyst is preferably at least 0.30 cm3/g. Suitably, the total pore volume of the catalyst is at most 0.80 cm3/g.
The first metal component comprises one or more metals selected from the group consisting of copper, nickel, cobalt, and silver. Preferably, the first metal component is copper.
Said first metal component is present in amount of at least 0.1 wt%, preferably at least 1 %, more preferably at least 2 wt% based on the total weight of the finished catalyst. The first metal component is present in amount of at most 20 wt%, preferably at most 15 wt%, more preferably at most 10wt% based on the total weight of the finished catalyst.
The second metal component, when present, is suitably present in an amount of at least 0.01 wt%, preferably at least 0.1 wt%, more preferably at least 1 wt%, even more preferably at least 1.5 wt% based on the total weight of the finished catalyst. The second metal component is suitably present in an amount of at most 20 wt%, preferably at most 15 wt%, more preferably at most 12 wt%, based on the total weight of the finished catalyst .
In one preferred embodiment of the present invention, the second metal component comprises cerium and zirconium. In this embodiment, both the cerium and the zirconium are present individually in an amount of at least 0.01 wt%, preferably at least 0.1 wt%, more preferably at least 0.5 wt%, most preferably at least 1 wt% based on the total weight of the finished catalyst. The cerium and the zirconium are present individually in an amount of at most 10 wt%, preferably at most 8 wt%, more preferably at most 6 wt%, based on the total weight of the finished catalyst. In a particularly preferred embodiment of the present invention, the zirconium and cerium are present such that the ratio of zirconium to cerium (with respect to the mass of each metal present) is at least 1:1, preferably at least 1.5:1, more preferably at least 2:1. In this embodiment, suitably, the zirconium and cerium are present such that the ratio of zirconium to cerium is no more than 5:1, preferably no more than 4:1.
The process of the present invention is suitably carried out at a temperature in the range of from 400 to 800 0C, preferably in the range of from 500 to 700 0C. The process of the present invention may be carried out as a batch or a continuous process. However, the process is most preferably carried out in a continuous manner . The preferred catalyst composition of the present invention is suitably prepared by a process comprising the steps of (i) impregnating the alumina support, in a first impregnation step, with the cerium and zirconium components to form a first impregnated support; (ii) calcining the first impregnated support at a temperature in the range of from 300 to 850 °C to form a calcined first impregnated support; (iii) impregnating, in a second impregnation step, the calcined first impregnated support with the copper component to form a second impregnated support; and (iv) then calcining the second impregnated support at a temperature in the range of from 300 to 700°C.
The first impregnation step may be carried out by any suitable impregnation process. However, an incipient wetness impregnation method is preferred. The cerium and zirconium may be impregnated onto the alumina support either as separate aqueous solutions of cerium and zirconium salts or in a single impregnation solution comprising both cerium and zirconium salts. Preferably, the cerium and zirconium are impregnated onto the alumina support in a single impregnation solution comprising both cerium and zirconium salts. Preferred cerium and zirconium salts are nitrates.
Preferably, after the first impregnation step, the first impregnated support is dried. Any usual method of drying may be used. A preferred method is rotary drying.
After impregnation, the first impregnated support is calcined at a temperature in the range of from 300 to 850 0C, preferably in the range of from 500 to 700 0C. The second impregnation step may also be carried out by any suitable impregnation process. Again, an incipient wetness impregnation method is preferred. In a particularly preferred embodiment of the present invention, the second impregnation step involves the impregnation of the calcined first impregnated support with an aqueous solution comprising the copper component in the form of copper nitrate or copper citrate.
After impregnation, the second impregnated support is calcined at a temperature in the range of from 300 to 700 0C, preferably in the range of from 400 to 600 0C.
The present invention will now be illustrated by the following Examples. Examples 1 to 8 General Procedure
Eight catalysts were prepared according to the following general procedure. For contents and amounts, see Table 1. The catalysts were produced using a two-step incipient wetness impregnation method (95% pore volume). A high surface area gamma-alumina support (ex-Norpro) was firstly impregnated with an aqueous solution of cerium, lathanum or cerium/zirconium nitrate. The impregnated support was then dried by rotary drying at 80 0C and calcined at 500 0C using a heating profile of 2 0C per minute. For catalyst 1, the first impregnation, drying and calcination steps were omitted.
After cooling, the catalysts were impregnated with an aqueous solution of either copper nitrate or citrate. The impregnated supports were then dried by rotary drying at 80 0C and then calcined at 600 0C using a heating profile of 2 0C per minute. Table 1
Figure imgf000011_0001
* based on total weight of finished catalyst
The catalysts were compared against a catalyst consisting of a rhodium-cerium phase catalyst supported on 8.0 mm alpha alumina rings, which is termed λcatalyst 6' herein.
In the results as shown in the Figures, reduction or loss of activity is shown by an increased temperature required for the same level of conversion.
300 mg of each of crushed and sieved (30 to 80 mesh) catalysts 1 to 6 were tested in a nanoflow unit at a range of temperatures from 300 to 600 0C in a mixture of gases comprising 1500 ppm CH4, 5% H2O, 3% O2 and 22 % CO2 (balance argon) . The products were analysed by online mass spectrometry and the results are shown in Figure 1.
Figure 1 shows a reduction in activity of approximately 50 0C for the copper-based catalysts of the present invention compared to the rhodium-based catalyst. However, this is actually a benefit of the present invention as, in practice, the process stream to be treated is usually already at this higher temperature and, thus, the process of the present invention can be carried out without the need for venting heat, an adaptation which is usually required in order to protect a rhodium/cerium-based catalyst, such as catalyst 6.
The stability of catalysts 1 to 6 were then tested by following the same procedure, but applying a series of high temperature spikes (650 0C) for periods of 20 hours to the catalysts. The results are shown in Figure 2, which is a plot of the temperature required for each catalyst for 60% methane conversion after a number of run hours .
It is clear from Figure 2 that catalysts 1 to 5 (of the invention) outperform the prior art catalyst
(catalyst 6) in terms of stability with respect to high temperatures. After 150 hours on stream and 4 high temperature excursions, catalyst 6 lost approximately 80 0C in activity in comparison to an average of approximately 15 0C for catalysts 1 to 5. It is interesting to note that this loss in activity for catalysts 1 to 5 was only observed after the first temperature ramp, after subsequent temperature ramps little or no loss in activity was observed. Catalysts 1, 2, 4, 5, 7 and 8 were then tested under conditions to create/stimulate the aging of the catalyst. The crushed and sieved (30 to 80 mesh) catalysts were tested in a nanoflow unit at a range of temperatures from 300 to 750 0C in a mixture of gases comprising 1500 ppm CH4, 25% H2O, 3% O2 and 22 % CO2 (balance argon) . The products were analysed by online mass spectrometry and the results are shown in Figure 3. This demonstrates that for preferred embodiments of the invention, the catalysts demonstrate excellent stability in high levels of water vapour. Prior art catalysts, such as catalyst 6, are known to have low stability in the presence of such high levels of water vapour. Example 9
Catalyst 9 was produced using a two-step incipient wetness impregnation method (95% pore volume) . A high surface area gamma-alumina support (ex-Norpro) was firstly impregnated with an aqueous solution of cerium nitrate and zirconium nitrate. The impregnated support was then dried by rotary drying at 120 0C and calcined at 500 0C using a heating profile of 2 0C per minute. After cooling, the catalysts were impregnated with an aqueous solution of either copper nitrate. The impregnated supports were then dried by rotary drying at 120 0C and then calcined at 600 0C using a heating profile of 2 0C per minute.
The catalyst properties are as follows:
Amount of copper: 5.5 wt%
Amount of cerium: 1.4 wt%
Amount of Zr: 2.9 wt% Amount of alumina: Balance
(all based on total weight of finished catalyst) BET surface area: 167 m2/g Mercury pore volume: 0.50 cm3/g.

Claims

C L A I M S
1. A process for the removal of combustible volatile contaminant materials from a first process stream, which comprises combusting the volatile materials in the presence of a catalyst composition which comprises a support comprising gamma-alumina; a first metal component which comprises one or more metals selected from the group consisting of copper, nickel, cobalt, and silver; and optionally a second metal component which comprises one or more metals selected from the group consisting of lanthanum, cerium, and zirconium to form a cleaned stream, which also contains combustion products.
2. A process as claimed in claim 1, wherein the first metal component is copper.
3. A process as claimed in claim 1 or claim 2, wherein the second metal component is present and is cerium and zirconium.
4. A process as claimed in any one of claims 1 to 3, wherein the temperature of combustion is in the range of from 400 to 800 °C.
5. Catalyst composition which comprises a copper component, a cerium component and a zirconium component on a support comprising gamma-alumina.
6. Catalyst composition as claimed in claim 5, wherein the cerium and zirconium are present in a ratio of metal mass in the range of from 1:1 to 1:4.
7. Catalyst composition as claimed in claim 5 or claim 6, wherein the copper component is present in an amount in the range of from 0.1 to 20 % by weight based on the total weight of the finished catalyst.
8. Process for the preparation of a catalyst composition, as claimed in any one of claims 5 to 7, wherein in a first impregnation step the support comprising gamma-alumina is impregnated with the cerium and zirconium components to form a first impregnated support; the first impregnated support is then calcined at a temperature in the range of from 300 to 850 °C to form a calcined first impregnated support; and then in a second impregnation step the calcined first impregnated support is impregnated with the copper component to form a second impregnated support and then the second impregnated support is calcined at a temperature in the range of from 300 to 700°C.
9. Process as claimed in claim 8, wherein the first impregnated support is calcined at a temperature in the range of from 500 to 700°C.
10. Process as claimed in claim 8 or claim 9, wherein the copper component is copper nitrate or copper citrate.
PCT/EP2010/056528 2009-05-12 2010-05-12 Removal of contaminant materials from a process stream WO2010130772A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP09159963.9 2009-05-12
EP09159963 2009-05-12

Publications (1)

Publication Number Publication Date
WO2010130772A1 true WO2010130772A1 (en) 2010-11-18

Family

ID=42536431

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2010/056528 WO2010130772A1 (en) 2009-05-12 2010-05-12 Removal of contaminant materials from a process stream

Country Status (1)

Country Link
WO (1) WO2010130772A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108906048A (en) * 2018-06-08 2018-11-30 华南农业大学 A kind of carbon copper-clad nanoparticle and its preparation method and application with core-shell structure
CN111921532A (en) * 2020-09-07 2020-11-13 山东大学 VOCs waste gas catalytic oxidation catalyst, preparation method thereof, catalytic oxidation device and method
CN115501876A (en) * 2022-09-19 2022-12-23 清华大学 Monolithic catalyst, preparation method and application thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1197259A1 (en) * 2000-10-11 2002-04-17 Süd Chemie Mt S.R.L. Oxidation catalysts
CN100411734C (en) * 2006-07-28 2008-08-20 华南理工大学 Method for combination preparation of CuO/CeO2/gamma-Al2O by use of ultrasound-plasma
US20090062116A1 (en) * 2007-08-31 2009-03-05 Chao-Yuh Chen Vermiculite supported catalyst for CO preferential oxidation and the process of preparing the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1197259A1 (en) * 2000-10-11 2002-04-17 Süd Chemie Mt S.R.L. Oxidation catalysts
CN100411734C (en) * 2006-07-28 2008-08-20 华南理工大学 Method for combination preparation of CuO/CeO2/gamma-Al2O by use of ultrasound-plasma
US20090062116A1 (en) * 2007-08-31 2009-03-05 Chao-Yuh Chen Vermiculite supported catalyst for CO preferential oxidation and the process of preparing the same

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
KUNDAKOVIC L ET AL: "Cu- and Ag-Modified Cerium Oxide Catalysts for Methane Oxidation", JOURNAL OF CATALYSIS, ACADEMIC PRESS, DULUTH, MN, US LNKD- DOI:10.1006/JCAT.1998.2213, vol. 179, no. 1, 1 October 1998 (1998-10-01), pages 203 - 221, XP004447325, ISSN: 0021-9517 *
M. OZAWA, JOURNAL OF ALLOYS AND COMPOUNDS, vol. 408-412, 2000, pages 1090 - 1095
TERRIBILE D ET AL: "Catalytic combustion of hydrocarbons with Mn- and Cu-doped ceria-zirconia solid solutions", CATALYSIS TODAY, AMSTERDAM, NL LNKD- DOI:10.1016/S0920-5861(98)00292-2, vol. 47, 1 January 1999 (1999-01-01), pages 133 - 140, XP002295320 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108906048A (en) * 2018-06-08 2018-11-30 华南农业大学 A kind of carbon copper-clad nanoparticle and its preparation method and application with core-shell structure
CN108906048B (en) * 2018-06-08 2021-04-23 华南农业大学 Carbon-coated copper nanoparticle with core-shell structure and preparation method and application thereof
CN111921532A (en) * 2020-09-07 2020-11-13 山东大学 VOCs waste gas catalytic oxidation catalyst, preparation method thereof, catalytic oxidation device and method
CN115501876A (en) * 2022-09-19 2022-12-23 清华大学 Monolithic catalyst, preparation method and application thereof

Similar Documents

Publication Publication Date Title
JP6486360B2 (en) Carbon monoxide and / or oxidation catalyst for volatile organic compounds
US20090130010A1 (en) Catalyst fo the decomposition of n2o in the ostwald
RU2684908C2 (en) Nitrous oxide decomposition catalyst
US20090200207A1 (en) Absorption Composition and Process for Removing Mercury
TW201503956A (en) Method for regenerating catalyst for hydrogenation reaction, and method for producing hydride of polyhydric alcohol
WO2010130772A1 (en) Removal of contaminant materials from a process stream
JP2005254232A (en) Catalyst for decomposition of n2o in ostwald method
TWI498159B (en) Catalyst and process
KR20060007409A (en) Improved catalyst charge design
CN105642282B (en) A kind of catalyst for dehydrogenation of low-carbon paraffin and its preparation method and application
JP4025945B2 (en) Methane-containing exhaust gas purification catalyst and methane-containing exhaust gas purification method
Heneghan et al. AND STUART H. TAYLOR
JP2005029466A (en) Process to eliminate sulphur-containing compounds by direct oxidation
KR102223388B1 (en) Preparation method of ruthenium-platinum-tin catalyst for hydrogenation of cyclohexane dicarboxylic acid (CHDA) and method for producing cyclohexane dimethanol (CHDM) using said catalyst
EP3057684B1 (en) Process for the removal of chlorinated hydrocarbons from co2
KR100402430B1 (en) Catalyst for decomposition of toxic pollutants and producing process thereof
CN117813147A (en) Method and HVAC system for treating exhaust gas
WO2008090450A1 (en) Process for catalytic decomposition of nitrogen protoxide
EP2026898B1 (en) Method for removing heavy metals from gases
JP5041848B2 (en) Method for treating halogenated aliphatic hydrocarbon-containing gas
KR101419041B1 (en) A method for low-temperature reduction of nitrous oxide using a reductant over platinum group bi-metallic catalysts containing copper as a primary component
JP4345472B2 (en) Method for removing sulfur compounds
JP2023072888A (en) Method for regenerating catalyst for nitrous oxide decomposition and method for decomposing nitrous oxide
JP6103955B2 (en) Methane oxidation removal catalyst and methane oxidation removal method
EP0993857B1 (en) Method for the catalytic oxidation of VOC/CO in the presence of organosilicate compounds

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10718225

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 10718225

Country of ref document: EP

Kind code of ref document: A1