Apparatus and method for continuously producing carbon nanotubes

Patent metadata

Field	Value
Publication number	US-9782738-B2
Application number	US-201313970131-A
Country	US
Kind code	B2
Filing date	Aug 19, 2013
Priority date	Apr 4, 2011
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

Disclosed are an apparatus and method for continuously producing carbon nanotubes, the apparatus includes i) a reactor to synthesize carbon nanotubes, ii) a separator to separate a mixed gas from the carbon nanotubes transferred from the reactor, iii) a filter to remove all or part of one or more component gases from the separated mixed gas, and iv) a recirculation pipe to recirculate the filtered mixed gas to the reactor for carbon nanotubes.

First claim

The invention claimed is:

1. An apparatus for continuously producing carbon nanotubes comprising:
i) a fluidized bed reactor to synthesize carbon nanotubes;
ii) a separator to separate a mixed gas from the carbon nanotubes transferred from the reactor;
iii) a hydrogen separation unit that processes removal of 19 to 34% of hydrogen (H 2 ) gas from the separated mixed gas;
iv) a recirculation pipe to recirculate the processed gas discharged from the hydrogen separation unit to the reactor for carbon nanotubes;
v) a reaction gas supply pipe connected to a bottom part of the reactor;
vi) a catalyst supply pipe arranged in an upper part of the reactor; and
vii) a product discharge pipe,
wherein a filter to collect residual CNT particles, a scrubber or a combination thereof is arranged between ii) the separator and iii) the hydrogen separation unit.

2. The apparatus according to claim 1 , wherein the fluidized bed reactor is connected to the catalyst supply pipe to supply a catalyst, the reaction gas supply pipe to supply a carbon source, a reducing gas, and an inert gas, and the product discharge pipe to discharge the produced carbon nanotubes and the mixed gas.

3. The apparatus according to claim 1 , wherein the separator is a cyclone.

4. The apparatus according to claim 1 , wherein the hydrogen separation unit is a hydrogen pressure swing adsorption (PSA) unit.

5. The apparatus according to claim 4 , wherein the hydrogen pressure swing adsorption (PSA) unit includes two or more adsorption towers and two or more flow direction control valves,
wherein the PSA unit includes a first flow direction control valve to direct the mixed gas discharged from the separator to a first adsorption tower to perform pressurization, a second flow direction control valve to direct the processed gas to the recirculation pipe and a third flow direction control valve to direct the removed one or more component gases discharged from a second adsorption tower, which is depressurized, toward a discharge gas disposal or hydrogen (H 2 ) storage unit, and
wherein, in the PSA unit, the first to third flow direction control valves are connected.

6. The apparatus according to claim 1 , wherein the hydrogen separation unit is a metal membrane gas separation unit.

7. The apparatus according to claim 6 , wherein the metal membrane gas separation unit selectively separates hydrogen at a temperature lower than 500° C.

8. The apparatus according to claim 6 , wherein the metal membrane gas separation unit is made of at least one metal selected from the group consisting of Pd, Ir, Rh, Pd—Ni alloys, Pd—Ag alloys and Pd—Cu alloys.

Assignees

• Lg Chemical Ltd

Inventors

• Chang Kwang-Hyun
• Kim Jin-Do
• Yoon Kwang-Woo

Classifications

• C01B31/024

  Chemistry & Metallurgy · mapped topic

• B01J8/0055 Primary

  using cyclones · CPC title

• B01J2208/00176

  outside the reactor · CPC title

• B01J2208/00274

  involving reactant vapours · CPC title

• C01B31/0226

  Chemistry & Metallurgy · mapped topic