# US 2019/0284728 A1 · Exhaust gas treatment method, exhaust gas treatment device, and carbon fiber manufacturing system

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- Number: US 2019/0284728 A1
- Document ID: US20190284728A1
- Status: Published application
- Kind: A1
- Application number: 16/318,208
- Filed: 2017-07-20
- Published: 2019-09-19
- Earliest claimed: 2016-07-20
- Assignees: Taiyo Nippon Sanso Corporation
- Applicants: Taiyo Nippon Sanso Corporation
- Inventors: Yasuyuki YAMAMOTO; Yoshiyuki HAGIHARA; Kimio IINO; Tomonobu ABE
- Web page: https://patentgrep.com/patent/US20190284728A1

## CPC

- D01F 9/12: Carbon filaments; Apparatus specially adapted for the manufacture thereof
- F23G 7/065: {using gaseous or liquid fuel}
- F23G 5/14: including secondary combustion
- F23G 5/16: in a separate combustion chamber
- F23G 5/32: the waste being subjected to a whirling movement, e.g. cyclonic incinerators
- F23G 7/06: of waste gases or noxious gases, e.g. exhaust gases (exhaust apparatus for engines with means for rendering the exhaust innocuous, e.g. by thermal or catalytic conversion, F01N3/08; combustion of uncombusted material from primary combustion within apparatus for combustion of solid or fluent fuel F23B {, of non combusted material from primary combustion of solid fuels; of gases produced by primary combustion of solid fuels F23B90/04}, F23C)
- F23G 2202/101: with controlled oxidant supply
- F23G 2202/102: with supplementary heating
- F23G 2202/103: in separate chambers
- F23G 2202/105: with waste supply in stages
- F23G 2204/103: gaseous or liquid fuel
- F23G 2207/30: Oxidant supply
- F23G 2209/14: Gaseous waste or fumes
- Y02E 20/34: Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- F23G: CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

One object of the present invention is to provide an exhaust gas treatment method for treating exhaust gases discharged from a carbon fiber manufacturing steps which can suppress a cost increase due to an increase in an amount of an exhaust gas treated, the present invention provides an exhaust gas treatment method including: a first combusting step in which a carbonizing step-exhaust gas discharged from a carbonizing step in which the fibrous substance is carbonized in an inert gas atmosphere is treated; and a second combusting step in which a flameproofing step-exhaust gas discharged from a flameproofing step in which the fibrous substance is flameproofed in an air atmosphere and a first combusting step-exhaust gas discharged from the first combustion step are treated; and an air separating step in which nitrogen for producing the inert gas atmosphere in the carbonizing step, and the oxygen-enriched air used in the first combusting step are produced by separating air.

## Claims

### Claim 1

An exhaust gas treatment device which is configured to treat exhaust gases discharged from steps of manufacturing carbon fiber from a fibrous substance,
wherein the exhaust gas treatment device includes:
a first combustion furnace which is configured to combust a carbonizing step-exhaust gas discharged from a carbonizing step in which the fibrous substance is carbonized in an inert gas atmosphere; and
a second combustion furnace which is provided at a post-stage of the first combustion furnace, and configured to combust a flameproofing step-exhaust gas discharged from a flameproofing step in which the fibrous substance is flameproofed in an air atmosphere and a first combusting step-exhaust gas discharged from the first combustion furnace;
the first combustion furnace and the second combustion furnace communicate through a throttle portion;
the first combustion furnace is provided with a first burner which is configured to combust a carbonizing step-exhaust gas by a fuel and an oxygen-enriched air; and
an air separation device which is configured to produce nitrogen for producing the inert gas atmosphere in the carbonizing step and the oxygen-enriched air supplied into the first burner.

### Claim 2 (depends on 2)

The exhaust gas treatment device according to claim 2, wherein the exhaust gas treatment device further includes a second burner which is configured to supply a fuel into the second combustion furnace.

### Claim 3

An exhaust gas treatment method for treating exhaust gases discharged from steps of manufacturing carbon fiber from a fibrous substance,
wherein the exhaust gas treatment method includes:
a first combusting step in which a carbonizing step-exhaust gas discharged from a carbonizing step in which the fibrous substance is carbonized in an inert gas atmosphere is treated; and
a second combusting step in which a flameproofing step-exhaust gas discharged from a flameproofing step in which the fibrous substance is flameproofed in an air atmosphere and a first combusting step-exhaust gas discharged from the first combustion step are treated;
in the first combusting step, the carbonizing step-exhaust gas is combusted at a low oxygen ratio of 0.8 or less by a fuel and an oxygen-enriched air;
in the second combusting step, the first combusting step-exhaust gas and the flameproofing step-exhaust gas are combusted by using heat of the first combusting step-exhaust gas; and
nitrogen for producing the inert gas atmosphere in the carbonizing step, and the oxygen-enriched air used in the first combusting step are produced by separating air.

### Claim 4 (depends on 3)

The exhaust gas treatment method according to claim 3, wherein the combustion of the first combusting step-exhaust gas and the flameproofing step-exhaust gas is promoted by supplying a fuel in the second combusting step.

### Claim 5

A carbon fiber manufacturing equipment including equipment which is configured to produce carbon fiber from a fibrous substance, and exhaust gas treatment equipment which is configured to treat exhaust gases from the equipment which is configured to produce carbon fiber from a fibrous substance,
wherein the carbon fiber manufacturing equipment includes:
a flameproofing furnace which is configured to pre-oxidize and flameproof the fibrous substance in an air atmosphere;
a carbonizing furnace which is provided at a post-stage of the flameproofing furnace and configured to carbonize the fibrous substance after flameproofing in an inert atmosphere;
a first combustion furnace which is configured to combust a carbonizing step-exhaust gas discharged from the carbonizing furnace;
a second combustion furnace which is configured to communicate with the first combustion furnace through a throttle portion, and combust a first combusting step-exhaust gas and a flameproofing step-exhaust gas discharged from the flameproofing furnace;
a first burner which is provided in the first combustion furnace so as to combust the carbonizing step-exhaust gas by a fuel and an oxygen-enriched air; and
an air separation device which is configured to produce nitrogen for producing the inert gas atmosphere in the carbonizing furnace and the oxygen-enriched air supplied into the first burner from air.

### Claim 6

A carbon fiber manufacturing system including a step in which carbon fiber is produced from a fibrous substance and a step in which exhaust gases discharged from the step in which carbon fiber is produced from a fibrous substance are treated,
wherein the carbon fiber manufacturing system includes:
a flameproofing step in which the fibrous substance is pre-oxidized and flameproofed at 200° C. to 300° C. in an air atmosphere;
a carbonizing step in which the fibrous substance after the flameproofing step is carbonized at 300° C. to 2,000° C. in an inert gas atmosphere;
a first combusting step in which a carbonizing step-exhaust gas discharged from the carbonizing step is combusted at a low oxygen ratio of 0.8 or less by a fuel and an oxygen-enriched air;
a second combusting step in which a first combusting step-exhaust gas discharged from the first combusting step and a flameproofing step-exhaust gas discharged from the flameproofing step are combusted using heat of the first combusting step-exhaust gas; and
an air separating step in which nitrogen for producing the inert gas atmosphere in the carbonizing step, and the oxygen-enriched air used in the first combusting step are produced by separating air.