Process for simultaneously removing nitrogen oxides, sulfur oxides, and particulates

Claim 1

A gas purification process, comprising the steps of: simultaneously substantially removing nitrogen oxides, sulfur oxides, and particulates in a common vessel from a gaseous stream containing nitrogen oxides, sulfur oxides, and particulates by contacting said gaseous stream with a nitrogen oxide-capturing reducing agent and passing said gaseous stream generally vertically through at least a portion of a bed of granular sulfur oxide-capturing and particulate-removing material, liberating nitrogen and steam and leaving spent granular material carrying removed particulates and sulfur-containing deposits thereon comprising at least one member of the group consisting of sulfur oxides, sulfates, and combinations thereof; said sulfur oxide-capturing and particulate-removing material being selected from the group consisting essentially of adsorbers and adsorbers with at least one promoter thereon, said adsorbers comprising an oxide of at least one metal selected from the group consisting of aluminum, bismuth, manganese, yttrium, antimony. tin, rare earth metals, Group 1a metals, and Group 2a metals, and said promoter comprising at least one member, in a free or combined form, selected from the group consisting of rare earth metals, Group 8 noble metals, chromium, vanadium, rhenium, antimony, silver, and combinations thereof; said nitrogen oxides being substantially removed by a nitrogen oxide-capturing reducing agent selected from the group consisting essentially of hydrogen, ammonia, ammonia-liberating compounds, light hydrocarbon gases, and combinations thereof; simultaneously removing said particulates and sulfur-containing deposits from said spent material in a regenerator while converting said sulfur-containing deposits to hydrogen sulfide in said regenerator by reacting said spent material with a regenerating reducing gas selected from the group consisting essentially of hydrogen, ammonia, ammonia-liberating compounds, carbon monoxide, gas oils, light hydrocarbon gases, and combinations thereof, to provide regenerated material for use in said bed; and feeding said regenerated material directly from said regenerator to said bed in said vessel without substantially heating, cooling, or tempering said regenerated material.