Chemical synthesis and material processing in the highly reactive environment of a gas plasma has been a fertile field of research. The plasma state is well suited to such applications, as the ionized gas may be both an energy transfer medium and a source of reactive intermediates. The wide variety in the literature is due not only to the vast array of chemical systems of interest, but also to the manifold methods of plasma operation and plasma-solid contacting. Historically, many of the difficulties in effecting plasma-solid reactions have been related to the contacting schemes employed.
The plasma-fluidized-bed reactor (PFBR) has been designed to effect the fluidized-bed contacting of a nonequilibrium gas plasma with granular solid material. The reactor is a solids bed fluidized by a subatmospheric pressure, high-frequency (2.45 GHz) plasma within a cylindrical cavity resonator. The PFBR takes advantage of many of the properties of conventional gas fluidized-bed reactors, as, for example, well-mixed solids, isothermal operation, good temperature control, and fluid-like properties of the bed. Although fluid-bed contacting between solids and the tail region of a d.c. or r.f. plasma has been used for rapid quenching of the plasma jet (Goldberger and Oxley, 1963) as well as to effect spouted beds (Jurewicz, et al. 1985), the PFBR is unique in that it involves contact of solids with the active or current-carrying portion of the plasma in a fluidized bed.
The first of two objectives of this work is to demonstrate "proof of concept" of the PFBR, that is, to establish that it is possible to ionize the interstitial, intraslug, and intrabubble regions of a gas fluidized bed and to maintain such a reactor in steady operation.
Given the first objective, the second is the characterization of the properties of the PFBR as a fluidized bed and as a plasma reactor over ranges of gas, solid, and microwave cavity conditions. These characterization studies involve inert gases and solids and the results are compared with similar studies of labora-Correspondence concerning this papcr should be addressed to T.