Process for the purification of flue gas

Claim 2

A process for removing SO2 from flue gas comprising the steps of continuously: a. removing solids from the flue gas in a solid separation zone; b. passing the flue gas to a fixed flue gas input zone; c. passing said flue gas at a temperature of about 600* to about 900* F. from said input zone to and through a mass of an absorption catalyst comprising potassium oxide and vanadium pentoxide and arranged in rotatable sectorial catalyst compartments as each of said compartments is rotated to a position opposite the input zone, whereby SO2 is absorbed on the catalyst as the flue gas passes through the compartments in intimate contact with the catalyst; d. passing SO2-free flue gas to a fixed flue gas recovery zone which is in substantially linear flow alignment with said fixed flue gas input zone; e. rotating the catalyst compartments containing absorbed SO2 to register with an oxygen containing gas input zone; f. passing an oxygen containing gas at a temperature of about 900* to about 1,200* F. to and through each sectorial catalyst compartment as each of said catalyst compartments containing absorbed SO2 registers with the oxygen containing gas input zone whereby SO2 is converted to SO3 and SO3 is desorbed from the catalyst as the oxygen containing gas passes through the compartments in intimate contact with the catalyst g. passing SO3 rich gas to a fixed gas recovery zone which is in substantially linear flow alignment with said oxygen containing gas input zone; h. passing said SO3 rich gas into a sulfuric acid contacting zone; i. a recovering sulfuric acid of increased concentration.

Claim 3

A process for the purification of flue gas containing SO2 comprising the steps of: a. passing flue gas from a flue to a solids separation zone wherein solids are removed from the gas; b. passing said gas at a temperature of about 600* to about 900* F. to a rotating reactor, said reactor being divided into a plurality of contacting zones, each zone containing catalyst comprising potassium oxide and vanadium pentoxide disposed within the zone so that a maximum amount of gas-catalyst contact is achieved with a minimum amount of pressure drop; c. passing said gas into an end of each of said zones as the zone rotates to a position opposite the gas input line; d. passing said gas through each contacting zone whereby the gas intimately contacts the catalyst and the SO2 in said gas is absorbed by the catalyst; e. rotating each of said absorbed SO2 containing zones to a position opposite an air input line; f. passing air at a temperature of about 900*to about 1,200* F. through each of said SO2 containing zones whereby SO2 is converted to SO3 ; g. absorbing the SO3 in H2SO4 ; h. and recovering H2SO4 of increased concentration.

Claim 4

In a process for the purification of flue gas involving absorbing SO2 in said gas on a catalyst comprising potassium oxide and vanadium pentoxide and converting SO2 to SO3 by desorbing with an oxygen containing gas, the improvement which comprises carrying out the absorption at a temperature of about 900* to about 1,200* F., continuously rotating the catalyst mass sequentially to and through an absorption stage and then to and through a desorption stage, said stages being operated simultaneously.

Claim 5

A process according to claim 5 in which the catalyst is in the form of fibers.

Claim 6

A process according to claim 5 wherein said catalyst comprises about 8 to 15 percent by weight of potassium oxide and about 5 to 10 percent by weight of vanadium pentoxide supported on a carrier.

Claim 7

A process according to claim 7 in which carrier is silica.