A means of scaling up fluidized bed chemical vapor deposition (FBCVD) production by using two or more small reactors instead of one large reactor. Each reactor has its own process gas delivery and exhaust lines. The furnace heating is designed such that each reactor has its own heater or there may be one large heater designed to keep the group of reactors at a constant temperature. This allows the shut down of a failed reactor without affecting production from other reactors.
 This invention was made, in part, with government support under Contract No. DE-AC07-05ID14517 awarded by the Department of Energy. The United States government has certain rights in this invention.