The chemical elements of hydrogen, halogen (fluorine, chlorine, bromine, iodine and astatine), oxygen, sulfur, phosphorus, silicon, nitrogen, boron, selenium, tellurium, and noble gases (helium, neon, argon, krypton, xenon and radon).

Compounds solely composed of any of the elements listed above.

Carbon and compounds of carbon with any of the elements listed above, with the proviso that said compounds cannot contain a carbon atom having direct bonding to another carbon atom, a carbon atom having direct bonding to a hydrogen atom or a halogen atom, or a carbon atom having direct bonding to a nitrogen atom by a single or double bond.

Compounds composed solely of one or more metal atoms and hydrogen.

Peroxides and salts of peroxyacids.

Magnesium, calcium, strontium, or barium sulfides or polysulfides.

Alkali metal sulfides or polysulfides.

Thiosulfates, dithionites and polythionates.

Compounds containing selenium or tellurium.

Azides, metal amides and nitrites.

Carbamic acid and salts thereof.

Binary compounds containing a metal and either N, C or P.

Salts of the oxyacids of halogen or phosphorus.

Compounds consisting only of carbon atoms, e.g. fullerenes, carbon nanotubes.

Phosgene and thiophosgene.

Compounds containing silicon such as silicates, silicon oxides or colloidal silica, e.g. dispersions, gels, hydroorganosols, organosols.

Compounds containing boron.

Substances having molecular sieve properties, but not having base-exchange properties.

Substances having a combination of molecular sieve and base-exchange properties, e.g. crystalline zeolites.

Synthesis, treatment or modification of any of the elements or compounds above by:

Methods of preparing the following compounds, in general:

Apparatus:

In Class C01, in the absence of an indication to the contrary, a compound is classified in the last appropriate subclass of this class. For example, lead oxide is classified in subclass C01G rather than in this subclass.

This subclass is a function oriented entry for the chemical elements and their compounds and does not cover the application or use of the elements and compounds under the subclass definition. For classifying such information other entries in IPC exist, for example:

Salts, adducts, or complexes formed between an inorganic compound of this subclass and an organic compound of class C07, are regarded as organic compounds and classified in class C07.

When a process produces multiple compounds only those which are intended or desired require classification and classification may be proper in multiple subclasses.

Biocidal, pest repellant, pest attractant, or plant growth regulatory activity of chemical compounds or preparations is further classified in A01P.

Therapeutic activity of chemical compounds or medicinal preparations is further classified in subclass A61P.

Uses of cosmetics or similar toilet preparations are further classified in subclass A61Q.

In this subclass, in the absence of an indication to the contrary, a compound or a process of making a compound appropriate for this subclass is classified in the last appropriate place.

This subclass provides for products which are intended or desired. When a process produces multiple compounds only those which are intended or desired require a classification. However, by-products can be given an additional classification if they or the processes for obtaining them are considered of interest for search.

Inorganic salts of a compound, unless specifically provided for elsewhere, are classified as that compound.

In this group symbols of groups B01J 2208/00 and B01J 2219/00 should be added, for details relating to the reactors used in the generation of hydrogen or synthesis gas.

In groups C01B 3/12 - C01B 3/18 and in groups C01B 3/22 - C01B 3/586, symbols of group C01B 2203/00 should be added, for aspects relating to hydrogen or synthesis gas preparation processes.

In all of the groups C01B 3/0026 - C01B 3/0084, the metallic storage materials may contain minor quantities of non-metals such as B, C, O, S, Se, Si; e.g. C01B 3/0036 "only containing iron and titanium" includes Fe-Ti compositions comprising a minor quantity of non-metals.

Reversible uptake of hydrogen characterised by the uptaking medium being organic compounds, solutions thereof, e.g. metal organic frameworks

Reversible uptake of hydrogen characterised by the shape of the solid storage uptaking medium, e.g. hydrogen storage in glass beads amongst others.

Production of hydrogen or gaseous mixtures containing hydrogen by decomposition of gaseous or liquid organic compounds or by an incomplete decomposition.

For example, a dehydrogenation specifically meant for the production of hydrogen will also be classified in this group.

If the documents does not specify the type of gaseous or liquid organic compound further and if it is not mentioned whether a catalyst is used, classify in C01B 3/32.

If it concerns a catalytic process, but if the type of gaseous or liquid organic compound is not further specified, then classify in C01B 3/38 and subgroups or in C01B 3/40.

Production of hydrogen or of gaseous mixtures containing hydrogen by catalytic reaction of gaseous or liquid organic compounds other than hydrocarbons with gasifying agents characterised by the catalyst.

Multi-step process of hydrogen's or of gaseous mixtures containing hydrogen's production by catalytic reaction of hydrocarbons with gasifying agents, including also autothermal reforming.

Chemical or physical processes in general and their relevant apparatus are classified in B01J

This class is only to be allocated when the external heating is explicitly mentioned.

Production of hydrogen or of gaseous mixtures containing hydrogen by catalytic reaction of gaseous or liquid organic compounds other than hydrocarbons with gasifying agents characterised by the catalyst.

This group covers separation or purification processes in which hydrogen or the hydrogen containing gas is removed from the gaseous mixtures

The removal of one or more impurities from hydrogen or a hydrogen containing gas from the gaseous mixture.

This group only covers documents directed to the preparation of water, water being the product.

This group covers documents, in which metal hydrides are claimed per se and documents, in which the preparation of metal hydrides is disclosed.

Particular individual halides according to the element combined with the halogen are classified in the relevant groups C01B - C01G.

Oxides or oxyacids of halogens or salts thereof when claimed as such and the preparation thereof.

The preparation of oxygen, ozone, oxides and hydroxides.

Purification and separation processes related to the production of oxygen

In groups C01B 13/0229 - C01B 13/0288, additional features relating to the purification or separation processes are indexed with symbols chosen from C01B 2210/0026 - C01B 2210/0098.

In this group, processing steps are also classified with symbols chosen from C01B 2210/0001 - C01B 2210/0025.

When ozone is produced by generation of a plasma, the document is classified in C01B 13/10 and not in C01B 13/11.

Process for preparation of ozone and its apparatus are classified in C01B 13/11 subgroups.

Devices for providing corona discharge are classified in H01T 19/00 subgroups.

Process for preparation of ozone by ultraviolet light, the apparatus is also classified in B01J 19/123

When ozone is produced by generation of a plasma, the document is classified in C01B 13/10 and not in C01B 13/11.

In groups C01B 13/11 and C01B 13/115, additional features relating to the preparation of ozone by electrical discharge are classified with symbols chosen from C01B 2201/00 - C01B 2201/90.

Methods for preparing (hydr)oxides in general, not specific to a particular (hydr)oxide

Particular individual oxides or hydroxides are classified in the relevant groups of subclasses C01B - C01G or C25B, according to the element combined with the oxygen or hydroxy group

Contrary to the strict interpretation of the wording of the groups of C01 does this group dealing with the preparation of (hydr)oxides also comprise the after-treatment (C01B 13/145) and the purification (C01B 13/16).

All methods for purification of oxides or hydroxides in general

The purity of compounds in solid compounds in C01 is also covered by the group C01P 2006/80

The decomposition by application of heat without the addition of other reactants. Starting solutions can be sprayed but the obtained dried precursor is subsequently in a separate step decomposed by heat.

The oxidation or hydrolysis of metal (oxy)halides only.

The oxidation or hydrolysis of (e.g. organic) metal compounds, in pure form ('in the liquid state' in subgroup C01B 13/326 ) or dissolved in a non-aqueous (e.g. alcohol) solution ('in solution'). The 'sol-gel process' is classified in here.

Precipitation reactions, e.g. from a metal salt by adding a base like NaOH or NH₃

Mixtures of oxides or hydroxides including mixed (hydr)oxides, i.e. plural metal oxides or hydroxides and also mixtures of metal oxides and hydroxides

Processes whereby a pressure above one bar is realised by heating an aqueous solution above 100°C in a closed container (autoclave).

Peroxides, peroxyhydrates, peroxyacids and salts thereof, superoxides and ozonides when claimed as such and the preparation processes thereof.

Compositions consisting of elemental sulfur or of sulfur compounds as far as not classified in groups following C01B 17/98 according to the other elements (like transition metals) present. This groups includes preparations of such compositions as well as after-treatments in general, thus in so far these are not limited to one specific application. Also included are apparatus specially adapted to the preparation.

Preparation of elemental sulfur only.

e.g. block melting

All types of removal of all kind of impurities irrespective the source of the sulfur.

All process whereby the sulfur source is a gaseous sulfur compound, e.g. H₂S, SO₂

All kind of operations applied to the feed gas, e.g. concentration by absorption, adsorption or purification (removal of non-sulfur components).

E.g. the thermal step of the Claus process.

Only constructional features of the reactor, including waste heat boilers and the like connected therewith.

Only multi-combustion in two separate furnaces.

Two oxidizer gas flows to one single reactor is classified in C01B 17/0413 (or C01B 17/0417 when it concerns the reactor).

The compositions are considered to include supports.

Mechanical adaptations of the catalytic reactor for comprising the catalyst are classified in C01B 17/043.

Measures dealing with the separation of the elemental sulfur after one or more of the separate steps of e.g. the Claus process.

E.g. adjustment of ratio of gas stream components.

Those processes whereby the tail gas from a Claus process plant are reused for obtaining sulfur, e.g. by concentration of H₂S or reduction of SO₂ present in the tail gas.

E.g. Clauspol process.

Reaction of SO₂ or SO₃ with all kind of reducing agents, gaseous, liquid or solid.

Reduction of SO₂, e.g. with natural gas.

Classification is also accomplished in C01B 3/04 because of the produced hydrogen.

Preparation, separation or purification of binary hydrogen-sulfur compounds.

Recovery of H₂S from gas streams.

Removal of all kind of impurities (gaseous, liquid or solid) from H₂S.

All compounds H2S1+x, wherein x>0

Methods for preparing sulfided or polysulfides in general, not specific to the chemical nature of the (poly)sulfide.

All documents in this group and its subgroups are classified in the C01P subgroups

All documents in this group and its subgroups are classified in the C01P subgroups

All compounds Me2S1+x, with x>0, Me=Na,K

All documents in this group and its subgroups are indexed according to the C01P-scheme

SO₂ and H₂SO₃

Process for the preparation and apparatus specifically adapted therefor.

All combustion processes sulfur, as solid, liquid or gas

Processes comprising the combustion of sulfur followed by the oxidation of SO₂ into SO₃ are classified according to the step which makes the contribution over the prior art. A (further not specified) burning of sulfur with a specific oxidation catalyst is classified in C01B 17/78. A well defined burning step with a common oxidation into SO₃ is classified in C01B 17/54. In case both steps make the invention is the document classified in both groups.

Preparation of sulfur dioxide by separation, purification.

See also C01B 17/60

See also C01B 17/56

Methods of preparing sulfites in general and not specific to the chemical nature of the sulfite.

All features in relation to SO₃ or H₂SO₄ not classifiable in the subgroups of C01B 17/69.

All documents dealing with preparative features not classifiable in the subgroups of C01B 17/74.

All catalytic processes for the oxidation of SO₂ into SO₃. This group comprises features not classifiable in the subgroups of C01B 17/76.

In the contact processes the contact is the catalyst (a solid), it's then a gas/gas reactions in presence of a solid.

All conversion which includes more than one catalyst bed ('contact'), irrespective of whether they are present in one convertor or in several convertors.

All processes where in addition to the final absorber at least one other SO₃-absorption is present between the catalytic beds.

The presence in the starting solution of metallic ions is essential

Removal of some specific impurities are classified in C01B 17/905-C01B 17/908.

Removal of some specific impurities are classified in C01B 17/905-C01B 17/908.

Separating processes in general involving the treatment of liquids with ion exchange materials as adsorbents are classified in B01D15/04

Removal of some specific impurities are classified in C01B 17/905-C01B 17/908.

Purification of sulfuric acid in which the impurity is present.

See also C01B 17/92 in case of a mixture of acid and organic compounds.

Methods for the preparation of sulfates in general, and not specific to the chemical nature of the sulfate.

All documents in this group and its subgroups (so C01B 19/00 - C01B 19/04) are classified with symbols chosen from C01P-subgroups

The compounds classified in this group do have more than one element other than Se or Te, O and H not taken into account. The compounds with only one other element do find classification in the subgroups of this group.

This group comprises also mixtures of Se and Te.

All compounds of nitrogen insofar they are not classified according to the last place rule to groups after C01B 21/50, namely in C01C, C01D, C01F or C01G.

Obtaining nitrogen by preparation or synthesis.

All purifications or gas separations involving a liquefaction step: F25J

During classification are additional features classified using the groups C01B 2210/00-C01B 2210/0098 . Example of such features is the type of impurity removed (C01B 2210/0043).

Those processes comprising only chemical methods as e.g. specified by the subgroups C01B 21/0416- C01B 21/0427.

Chemical oxidation processes such as the removal of hydrogen by addition of oxygen to the feed gas. The impurity is oxidized.

Chemical reduction processes such as the removal of oxygen by addition of a reducing agent, like hydrogen. The impurity is reduced.

Those processes comprising only physical methods as e.g. specified by the subgroups C01B 21/0438- C01B 21/0488.

All processes comprising a sequence of steps each covered by the groups C01B 21/0411-C01B 21/0488

All processes comprising a sequence of steps each covered by the groups C01B 21/0411-C01B 21/0488 do get this symbol C01B 21/0494 in combination with symbols for the individual steps chosen from C01B 2210/00-C01B 2210/0025. Additional treatment steps which are the result of the main treatment operation are not recognised as separate step (e.g. removal of water by an adsorption step after the reductive treatment with hydrogen for the removal of oxygen during which the water is formed).

Groups for the type of impurity removed (C01B 2210/0043) are always applied as complete as possible.

E.g. mixed nitrides.

All compounds between carbon and nitrogen, CxNy

Preparing single crystals of GaN: C30B

Nitridation can take place by any nitrogen source, e.g. nitrogen, ammonia.

Processes whereby the boron oxide source is reduced with a carbon containing material like graphite or active carbon, carbon being elemental or not

Processes in which the nitrogen is provided by the precursor, although the reaction can take place in an ammonia or nitrogen containing atmosphere.

Nitridation can take place by any nitrogen source, e.g. nitrogen, ammonia.

Proce sses whereby the silicon oxide source is reduced with a carbon containing material like graphite or active carbon, carbon being elemental or not.

Nitridation can take place by any nitrogen source, e.g. nitrogen, ammonia.

Processes whereby the aluminium oxide source is reduced with a carbon containing material like graphite or active carbon, carbon being elemental or not.

Nitridation can take place by any nitrogen source, e.g. nitrogen, ammonia.

Processes whereby the metal oxide source is reduced with a carbon containing material like graphite or active carbon, carbon being elemental or not.

Processes whereby the nitrogen is provided by the precursor although these processes may be accomplished in an ammonia or nitrogen atmosphere.

All documents of this group and its subgroups up to C01B 21/0828 are fully classified with the symbols chosen from C01P subgroups

E.g. lithium amide: LiNH₂; lithium imide: Li₂NH

All oxides of nitrogen and their acids

Catalysts in general: B01J

Methods for the preparation of nitrates in general and not specific to the chemical nature of the nitrate.

Liquefaction or liquefying in general: F25J

During classification are additional features classified using the groups C01B 2210/00-C01B 2210/0098 . Example of such features is the type of impurity removed (C01B 2210/0043).

Those processes comprising only chemical methods not covered by the subgroups C01B 23/0021-C01B 23/0031.

Chemical oxidation processes such as removal of hydrogen by addition of oxygen to the feed gas. The impurity is oxidized.

Chemical reduction processes such as the removal of oxygen by addition of a reducing agent, like hydrogen. The impurity is reduced.

Those processes comprising only physical methods as e.g. specified by the subgroups C01B 23/0042-C01B 23/0089.

All processes comprising a sequence of steps each covered by the groups C01B 23/0015-C01B 23/0089

All processes comprising a sequence of steps each covered by the groups C01B 23/0015-C01B 23/0089 do get this symbol C01B 23/0094 in combination with symbols for the individual steps chosen from C01B 2210/00-C01B 2210/0025. Additional treatment steps which are the result of the main treatment operation are not recognised as separate step (e.g. removal of water by an adsorption step after the reductive treatment with hydrogen for the removal of oxygen during which the water is formed).

Groups for the type of impurity removed (C01B 2210/0043) or the type of noble gas obtained (C01B 2210/0029) are always applied as complete as possible.

Elemental phosphorus and compounds thereof. Included in this group are processes and apparatus used in obtaining these products. Also included in this group are processes and apparatus for after-treatments in general.of phosphorous compounds and not related to a specific phosphorous compound.

Also classified here are rare earth phosphates

C01B 25/232 takes precedence

Carbon and inorganic compounds thereof. Included in this group are processes and apparatus used in obtaining these products.

Preparation of carbonyl fluoride or carbonyl bromide.

C01B 32/60 covers preparation of carbonates or bicarbonates in general. Percarbonates are covered by C01B 15/10 and particular individual carbonates are covered by the relevant groups in C01B- C01G according to the cation.

In this main group and the subclass C01B, the last place priority rule is applied, i.e. at each hierarchical level, in the absence of an indication to the contrary, a compound is classified in the last appropriate place, however, the main groups C01B 21/00 and C01B 23/00 take precedence over this main group.

Preparation of intercalation compounds of graphite with fluorine are classified in C01B 32/22.

Preparation or purification of carbon products not referred to in C01B 32/15,C01B 32/20, C01B 32/25 or C01B 32/30, e.g. carbon gel, carbon aerogel, mesoporous carbon, ordered porous carbon or carbon.

All types of fullerenes, and their preparation; after-treatments thereof, e.g. purification, sorting, functionalization or dispersion in solvents.

All documents in C01B 32/158-C01B 32/178 are classified with symbols chosen from C01B 2202/00 - C01B 2202/36 to report structural aspects or properties of carbon nanotubes.

Mere references to "carbon nanotubes" in a document in the absence of other details do not lead to a classification in C01B 32/158. For example, a reference to a "carbon nanotube" grown on a substrate used for a semiconductor device is not sufficient for requiring a classification in C01B 32/158. If, however, the document includes specific details on how the nanotube is produced, treated, modified or purified which do not seem trivial, then the document is classified in C01B 32/158 - C01B 32/178. In other terms, documents referring to carbon nanotubes are not automatically classified in C01B 32/00 unless there is emphasis, e.g. on the nanotube growing technique or the after-treatment.

Catalysts, from which nanotubes were grown, e.g. composition, distribution, particle size or morphology.

After-treatments not addressed in C01B 32/17-C01B 32/178, e.g. coating of carbon nanotubes.

Methods for sorting or isolating as-grown mixtures of carbon nanotubes according to their (n, m) structural form, e.g. diameter, bandgap or electronic type (metallic versus semiconducting).

A document mentioning the storage of a gas using the physisorption or chemisorption properties of carbon nanotubes should be classified in the group concerned, for example a document addressing the storage of hydrogen should be classified in C01B 3/00, and further classified in the sorbent field, e.g. in B01J 20/00.

All nanosized carbon materials different from fullerenes and nanotubes, which are characterized by a specific structural aspect.

The production of graphene aerogel.

All documents in groups C01B 32/182 - C01B 32/196 are classified with symbols chosen from C01B 2204/00 - C01B 2204/32 to report structural aspects or properties of graphene.

After-treatment of graphene, e.g. sorting, derivatising or dispersing of graphene.

Graphene oxide.

Carbon activated by heating to high temperature in the presence of an activating agent for producing an internal porous particle structure.

Gaseous activation by means of combined-oxygen containing gases, such as steam and CO₂.

Activation in the presence of non-gaseous activating agents, e.g. ZnCl₂, H₃PO₄ or KOH.

Activation in the presence of a metallic compound, e.g. ZnCl₂.

C01B 6/00, C01B 21/00 and C01B 23/00 take precedence

Hydrides of silicon in the strict meaning of the term.

C01B 33/1465 takes precedence.

C01B 33/28 - C01B 33/2892: no longer to be used but cannot be deleted until splitting of groups to C01B 39/00 is completed. Use C01B 39/00 for classification

C01B 33/26 takes precedence.

Also classified here are documents interstratified clay-mica products.

Catalysts comprising molecular sieves are classified in the group B01J 29/00. Catalyst carriers are covered by appropriate groups of B01J 21/00 - B01J 29/00.

Solid sorbent composition comprising synthetic zeolitic molecular sieves are classified in B01J 20/00

Compounds classified in main group C01B 37/00 are also classified in other groups of class C01 according to their composition.

Metal organic framework materials (MOFs) is classified in C01B 39/00 or C01B 37/00 depending on their base-exchange properties

MOFs are also classified in C07F.

Silicates, metallosilicalites, metallozeosilites

aluminophosphates including other elements incorporated into the framework

Compounds classified in main group C01B 39/00 are also classified in other groups of class C01 according to their composition.

Metal organic framework materials (MOFs) are classified in C01B 39/00 or C01B 37/00 depending on their base-exchange properties.

MOFs are also classified in C07F.

Dealumination of an aluminosilicate zeolite and ion-exchange. Also classified there are documents in which there is a particular emphasis on a process for removing an organic structure directing agent occluded within the as-synthesized zeolite framework. If the removing of the organic structure directing agent is not the invention, only mentioned in the document, it's not classified.

The normal steps of zeolite preparation like synthesis mixture, washing, calcination are not considered as post treatment.

Preparation isomorphous zeolites (i.e. wherein the aluminium or silicon atoms in the framework are partly or wholly replaced by atoms of other elements, e.g. Ga, Ge, P or B) obtained by direct or secondary synthesis.

Zeolite of LTA structure

Groups C01B 39/023, C01B 39/026 and C01B36/06 take precedence

C01B 39/145 takes precedence

C01B 39/145 takes precedence

Groups C01B 39/023, C01B 39/026 and C01B36/06 take precedence

C01B 39/205 takes precedence

C01B 39/205 takes precedence

Groups C01B 39/023, C01B 39/026 and C01B36/06 take precedence

documents dealing with harmotome or phillipsite type materials.

Groups C01B 39/023, C01B 39/026 and C01B36/06 take precedence

Groups C01B 39/023, C01B 39/026 and C01B36/06 take precedence

Groups C01B 39/023, C01B 39/026 and C01B36/06 take precedence

Zeolites with framework topology code MAZ.

Groups C01B 39/023, C01B 39/026 and C01B36/06 take precedence

Groups C01B 39/023, C01B 39/026 and C01B36/06 take precedence.

only the identified type ZSM-8, ZSM-11, ZSM5/11 intermediate

The mixture of MFI and MEL frameworks, any intergrowth of MFI and MEL frameworks are classified in C01B 39/36

Groups C01B 39/023, C01B 39/026 and C01B36/06 take precedence

Groups C01B 39/023, C01B 39/026 and C01B36/06 take precedence

zeolites with specific X-ray diffraction pattern and defined composition not classifiable in the subgroups C01B 39/14 - C01B 39/445

Groups C01B 39/023, C01B 39/026 and C01B36/06 take precedence

Catalysts compositions are classified in the groups B01J 21/00 - B01J 29/00. Catalyst carriers are covered by appropriate groups of B01J 21/00 - B01J 29/00.