Spherical bed topping/hold-down media for an autothermal reformation/secondary reformation unit
A generally spherical high strength ceramic body for use in an ATR and/or SR unit covering a catalyst media bed. The ceramic body is a fully stabilized YSZ composite composition having at least about 13% yttria YSZ, and more typically from about 12% to about 20% yttria YSZ, with a porosity of less than 20 percent and a diameter of at least 25 mm and, more typically, selected from the group comprising 25 mm, 50 mm, 76 mm and 100 mm.
1. A substantially spherical ceramic body, comprising:
a generally spherical refractory body;
wherein the generally spherical refractory body has a diameter selected from the group consisting 25 mm, 38 mm, 50 mm, 76 mm, and 100 mm;
wherein the body is substantially YSZ, having a combined yttria and zirconia content of between about 95 weight percent and about 99 weight percent;
wherein the body has trace amount of impurities selected from the group consisting of alumina, silica, calcia, Fe2O3, titania, magnesia, Na2O, and K2O;
wherein the YSZ is fully stabilized.
2. The substantially spherical body of claim 1 , wherein the alumina content is about 3 weight percent; wherein the zirconia content is about 82 weight percent; wherein the yttria content is about 13 weight percent; and wherein the combined zirconia and yttria content is about 95 weight percent.