Carbon sequestration system and process and pyrolysis process and reactor

A process for producing carbon nanofilaments, the process comprising:

• feeding a reaction chamber containing carbon-sequestration catalyst particles with a continuous gaseous flow containing hydrocarbon compounds and carbon oxide through a gas inlet;
• inside the reaction chamber, introducing at least partially the gaseous flow into a first gas conduit mounted above the gas inlet and vertically spaced-apart therefrom, the first gas conduit being opened at both ends;
• and
• withdrawing gas from the reaction chamber through a gas outlet located above a bed of the catalyst particles contained in the reaction chamber;
• whereby, during operation, the catalyst particles are siphoned up and fluidized by the gaseous flow and travel up to the first gas conduit through a space defined between the first gas conduit and the gas inlet and through the first end of the first gas conduit, exits at the top end of the first gas conduit, and fall outside the first gas conduit to be recirculated.