Removing carbon nanotubes from a continuous reactor effluent

A method for producing carbon nanotubes, comprising:

• combining a feedstock and a recycle gas to give a feed gas fed to a reactor;
• reacting the feed gas with a catalyst in the reactor to form carbon nanotubes;
• discharging overhead from the reactor a continuous reactor effluent comprising the carbon nanotubes and catalyst particles;
• flowing the continuous reactor effluent through a catalyst separation vessel that isolates catalyst particles from the carbon nanotubes in the continuous reactor effluent and returns the catalyst particles via a recycle line to the reactor;
• flowing the continuous reactor effluent from the catalyst separation vessel through a carbon-nanotube separation vessel comprising a cyclonic separator comprising a multicyclonic separator having a swirl element that imparts radial acceleration and a tangential velocity component to the continuous reactor effluent;
• and
• separating carbon nanotubes from the continuous reactor effluent in the carbon- nanotube separation vessel, generating a waste stream comprising gaseous components from the continuous reactor effluent.

A system for producing carbon nanotubes, comprising:

• a reactor to react a feed gas comprising feedstock and a recycle stream with catalyst to form carbon nanotubes, the reactor comprising an outlet on an upper portion of the reactor to discharge overhead from the reactor a continuous reactor effluent comprising the carbon nanotubes and catalyst;
• a catalyst separation vessel to separate catalyst from carbon nanotubes in the continuous reactor effluent and return the catalyst via a recycle line to the reactor;
• a separation system to generate a first purified stream of the carbon nanotubes and a first residual stream comprising gaseous components from the continuous reactor effluent discharged from the catalyst separation vessel, wherein the separation system comprises a cyclonic separation system comprising a cyclonic separator;
• a filtration system to filter the first residual stream to generate a second purified steam of the carbon nanotubes and a second residual stream comprising the gaseous components, wherein the second residual stream is a waste gas stream;
• and
• a gas fractionation system to process the dry waste stream to give the recycle stream and an excess feed stream, wherein the waste stream comprises residual carbon nanotubes.