TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: The method further comprises purging solids and liquids from the first catalytic bed, the second catalytic bed, and the third catalytic bed by intermittently passing nitrogen through the beds to remove solids and liquids collected from the stack gases by the beds, or positioning a catalytic flow-through bed of natural calcium zeolite with a porosity of a total surface area of not greater than 1200 m2/g adapted to reduce sulfur oxides in a stack gas and passing stack gases comprising volatiles from combustion of coal or combustion of natural gas sequential through the catalytic bed with at least 90% reduction in sulfur oxides. The method comprises: providing the first catalytic bed, the second catalytic bed, and the third catalytic bed, which also remove at least 50%, preferably 90% of mercury from the stack gas and each beds are positioned between screens of 150-250 mesh on a moving disk; providing the two series of sequential through the first catalytic bed, the second catalytic bed, and the third catalytic bed parallel so stack gas can be cleaned by the method through one series of beds while other series of the beds can be cleaned; and positioning a fourth catalytic flow-through bed (30) of calcium zeolite comprising the natural zeolite particles in the stack before the first catalytic bed with an electrical charge on the fourth catalytic flow-through bed to collect bauxite compounds from the stack gases before passing through the first catalytic bed. The stack gases exiting from third catalytic bed through the stack have at least 95% reduction in sulfur oxides, nitrogen oxides, and carbon oxide compared to the stack gases delivered to the first catalytic flow-through bed and at least 95% reduction in bauxite compound, sulfur oxides, nitrogen oxides, and carbon oxide compared to the stack gases delivered to the fourth catalytic flow-through bed. The first catalytic bed, second catalytic bed, and third catalytic bed are: purged with liquid nitrogen to remove the solids and liquids from collected from stack gas by the beds; and each provided on a moving disk such that the stack gases in steps (c) and (d) can be continuously passed through the first catalytic bed, the second catalytic bed, and the third catalytic bed to provide collection of solids and/or liquids from the stack gases while other portions of the same bed or like beds are purged with nitrogen to remove the solids and liquids from the stack gas by the beds. The fourth catalytic flow-through bed is on a rotating disk so the stack gases are continuously moved through the fourth bed while other portions of the same beds or a like bed are purged with nitrogen to remove solids and liquids collected from the stack gas by the fourth bed. Preferred Components: The nitrogen is liquid nitrogen. The catalytic bed and other catalytic flow-through bed have a porosity of a total surface area of less than 800 m2/g.