Compounds, compositions and methods to reduce SOx emissions from FCC units
Anionic clay compounds such as hydrotalcite-like compounds can be made by a process wherein a non-hydrotalcite-like compound (or a hydrotalcite-like compound) are heat treated and then hydrated to form hydrotalcite-like compounds having properties (e.g., increased hardness and/or density) that differ from those of hydrotalcite-like compounds made by prior art methods wherein non-hydrotalcite-like compounds (or hydrotalcite-like compounds) are not similarly heat treated and hydrated to form such hydrotalcite-like compounds.
1. A solid solution comprising magnesium and aluminum and at least one SO 2 →SO 3 oxidation catalyst comprising a metal selected from the group consisting of cerium, vanadium, platinum, palladium, rhodium, molybdenum, tungsten, copper, chromium, nickel, iridium, manganese, cobalt, iron, ytterbium and uranium prepared by the method comprising:
reacting a source of aluminum and a source of magnesium which are free of a hydrotalcite like compound to form a non-hydrotalcite like reaction product having a magnesium to aluminum ratio of 2:1 to 5:1 and thereafter;
heat treating said non-hydrotalcite like reaction product at a temperature in the range of from about 300° C. to about 850° C. until such reaction product displays an X-ray diffraction pattern having at least a reflection at a two theta peak position at about 43 degrees and about 62 degrees.
2. The solid solution of claim 1 , wherein the magnesium and aluminum are in a ratio of 2:1 to 4:1.
3. The solid solution of claim 1 , wherein the source of magnesium is magnesium hydroxy acetate, magnesium acetate, magnesium hydroxide, magnesium nitrate, magnesium carbonate, magnesium formate, magnesium chloride, magnesium aluminate, hydrous magnesium silicate, magnesium calcium silicate, or a mixture of two or more thereof.
4. The solid solution of claim 1 , wherein the source of aluminum is alumina sol, alumina gel, crystalline alumina, aluminum acetate, aluminum nitrate, aluminum hydroxide, aluminum carbonate, aluminum formate, aluminum chloride, hydrous aluminum silicate, aluminum calcium silicate, or a mixture of two or more thereof.
5. A composition comprising the solid solution of claim 1 and at least one SO 2 →SO 3 oxidation catalyst comprising a metal selected from the group consisting of cerium and vanadium.
6. The solid solution of claim 1 , made by a method comprising heat treating the reaction product to a temperature in the range of from about 300° C. to about 700° C.
7. The solid solution of claim 1 , made by a method comprising heat treating the reaction product to a temperature in the range of from about 400° C. to about 500° C.
8. A method for decreasing SO x emissions from a fluid catalytic cracking unit comprising adding the solid solution of claim 1 to the fluid catalytic cracking unit to reduce the SO x emissions.