Patent ID: 7993594

Claim:
A multistage reaction apparatus for continuous production of carbon nanotubes, comprising: a catalyst activation reactor having an activation feed inlet and a catalyst gas outlet, wherein the activation inlet is configured to receive an inactive catalyst and a reducing gas, wherein the catalyst activation reactor is configured to produce an activated catalyst by reacting the inactive catalyst with the reducing gas at a temperature between about 350° C. and about 900° C., wherein the catalyst gas outlet is configured to output the activated catalyst; an array of n interconnected fluidized-bed reactors, wherein n is an integer of at least 2, wherein each of the n interconnected fluidized-bed reactors comprises a reaction feed inlet, a gas distributor mounted inside the fluidized-bed reactor, and an exhaust gas-solid separator outlet, wherein the first fluidized-bed reactor in the array of n interconnected fluidized-bed reactors is in fluidic connection with the catalyst gas outlet of the catalyst activation reactor and is configured to receive the activated catalyst from the catalyst gas outlet, wherein the first fluidized-bed reactor is configured to receive a carbon feed and a gas mixture through its associated reaction feed inlet, wherein the first fluidized-bed reactor is configured to produce carbon nanotubes by reacting the carbon feed, the gas mixture with the activated catalyst at a temperature between about 500° C. and about 900° C., wherein one of the n interconnected fluidized-bed reactors is configured to output the carbon nanotubes to the subsequent adjacent reactor in the n interconnected fluidized-bed reactors, wherein at least one of the n interconnected fluidized-bed reactors comprises a plurality of reaction zones, wherein the plurality of reaction zones are positioned along the gravitation direction, wherein the plurality of reaction zones have increased volumes along the downward direction; and a product outlet on the nth fluidized-bed reactor in the array of n interconnected fluidized-bed reactors, the product outlet being configured to output the carbon nanotubes.