Patent ID: 8821806

Claim:
A reactor apparatus for pyrolyzing a hydrocarbon feedstock, the apparatus including: a reactor component comprising a refractory material in oxide form, the refractory material having a melting point of no less than 2060° C. and which remains in oxide form for at least one of i) when exposed to a gas having an oxygen partial pressure of 10 −15 bar, a carbon partial pressure above the carbon partial pressure of the zirconium carbide and zirconium oxide phase transition at the same temperature, and at temperatures below the temperature of the zirconium triple point at the oxygen partial pressure of 10 −15 bar; and ii) when exposed to a gas having an oxygen partial pressure of 10 −15 bar and at temperatures above the zirconium triple point at the oxygen partial pressure of 10 −15 bar, and wherein the refractory material includes a) at least 20 wt. % of a first grain mode based upon the total weight of the refractory material, the first grain mode having a D50 grain size in the range of from 5 to 2000 μm; and b) at least 1 wt. % of a second grain mode based upon the total weight of the refractory material, the second grain mode having a D50 grain size in the range of from 0.01 μm up to not greater than one-fourth the D50 grain size of the first grain mode; the first grain mode comprising yttria and the second grain mode comprising yttria.