Method of treating gases

A method for wet mass transferring at least one solute gas comprising sulfur dioxide from a process gas stream into a reacting medium which is an aqueous alkaline solution, comprising:

• (a) passing a gas stream containing at least one solute gas through an elongate conduit having an inlet thereto and an outlet therefrom;
• (b) injecting a liquid reacting medium capable of absorbing said at least one solute gas, directly into said gas stream under a suitable atomizing gas pressure from a plurality of dual fluid spray nozzles coaxially disposed in series in said conduit and spaced apart by a distance sufficient to form a spray pattern of said liquid reacting medium from each of said nozzles filling homogeneously the cross-section of said conduit without substantially overlapping each other and containing liquid droplets ranging in size from about 5 to about 100 microns, thereby to form a plurality of individual contact spray zones whereby mass transfer of said at least one solute gas into said reacting medium is carried out in a very efficient way due to the large interfacial surface are for mass transfer, turbulent mixing and relatively long residence time generated therein;
• (c) contacting said gas stream at said outlet end of said conduit with agglomeration means to agglomerate and remove entrained liquid droplets from the gas stream before said gas stream passes out of the outlet end;
• and
• (d) discharging a clean gas stream separated from said liquid reacting medium from the outlet end of the conduit.

A method for wet mass transferring at least one solute gas comprising sulfur dioxide from a stream into a reacting medium which is a metal oxide based oxide slurry solution, comprising:

• (a) passing a gas stream containing at least one solute gas through an elongate conduit having an inlet thereto and an outlet therefrom;
• (b) injecting a liquid reacting medium capable of absorbing said at least one solute gas, directly into said gas stream under a suitable atomizing gas pressure from a plurality of dual fluid spray nozzles coaxially disposed in series in said conduit and spaced apart by a distance sufficient to form a spray pattern of said liquid reacting medium from each of said nozzles filling homogeneously the cross-section of said conduit without substantially overlapping each other and containing liquid droplets ranging in size from about 5 to about 100 microns, thereby to form a plurality of individual contact spray zones whereby mass transfer of said at least one solute gas into said reacting medium is carried out in a very efficient way due to the large interfacial surface area for mass transfer, turbulent mixing and relatively long residence time generated therein;
• (c) contacting said gas stream at said outlet end of said conduit with agglomeration means to agglomerate and remove entrained liquid droplets from the gas stream before said gas stream passes out of the outlet end;
• and
• (d) discharging a clean gas stream separated from said liquid reacting medium from the outlet end of the conduit.

A method for wet mass transferring at least one solute gas from an acid gas stream comprising hydrogen sulfide and/or carbon dioxide into a reacting medium which is an aqueous alkanolamine solution, comprising:

• (a) passing a gas stream containing at least one solute gas through an elongate conduit having an inlet thereto and an outlet therefrom;
• (b) injecting a liquid reacting medium capable of absorbing said at least one solute gas, directly into said gas stream under a suitable atomizing gas pressure from a plurality of dual fluid spray nozzles coaxially disposed in series in said conduit and spaced apart by a distance sufficient to form a spray pattern of said liquid reacting medium from each of said nozzles filling homogeneously the cross-section of said conduit without substantially overlapping each other and containing liquid droplets ranging in size from about 5 to about 100 microns, thereby to form a plurality of individual contact spray zones whereby mass transfer of said at least one solute gas into said reacting medium is carried out in a very efficient way due to the large interfacial surface area for mass transfer, turbulent mixing and relatively long residence time generated therein;
• (c) contacting said gas stream at said outlet end of said conduit with agglomeration means to agglomerate and remove entrained liquid droplets from the gas stream before said gas stream passes out of the outlet end;
• and
• (d) discharging a clean gas stream separated from said liquid reacting medium from the outlet end of the conduit.

A method for wet mass transferring at least one solute gas from a gas stream into a reacting medium, comprising:

• (a) passing a gas stream containing at least one solute gas through an elongate conduit having an inlet thereto and an outlet therefrom;
• (b) injecting a liquid reacting medium capable of absorbing said at least one solute gas, directly into said gas stream under a suitable atomizing gas pressure from a plurality of dual fluid spray nozzles coaxially disposed in series in said conduit and spaced apart by a distance sufficient to form a spray pattern of said liquid reacting medium from each of said nozzles filling homogeneously the cross-section of said conduit without substantially overlapping each other and containing liquid droplets ranging in size from about 5 to about 100 microns, thereby to form a plurality of individual contact spray zones whereby mass transfer of said at least one solute gas into said reacting medium is carried out in a very efficient way due to the large interfacial surface area for mass transfer, turbulent mixing and relatively long residence time generated therein;
• (c) contacting said gas stream at said outlet end of said conduit with agglomeration means to agglomerate and remove entrained liquid droplets from the gas stream before said gas stream passes out of the outlet end;
• and
• (d) discharging a clean gas stream separated from said liquid reacting medium from the outlet end of the conduit, wherein said method is utilized to effect removal of SO.sub.2 from the off-gases emanating from a coal-fired boiler by employing an aqueous lime slurry as said reacting medium to remove fly ash, unreacted lime and reacted lime plus residual SO.sub.2 simultaneously to a substantial degree.

A method for wet mass transferring at least one solute gas from a process gas stream into liquid reacting medium for said solute gas capable of reacting with said at least one solute gas, comprising:

• (a) providing an elongate conduit having an inlet thereto and an outlet therefrom and which is divided into a plurality of individual gas-atomized liquid contact zones;
• (b) passing a gas stream containing at least one solute gas into the inlet end of the elongate conduit;
• (c) injecting said liquid reacting medium directly into said gas stream under a sufficient atomizing pressure from a plurality of dual-fluid spray nozzles coaxially disposed in said conduit one in each of the individual gas-atomized liquid contact zones to form a spray pattern from each of said nozzles filling homogeneously the cross-section of said conduit in each of the individual gas-atomized liquid contact zones and containing liquid droplets ranging in size from about 5 to about 100 microns, thereby to form a plurality of individual contact spray zones whereby mass transfer of said at least one solute gas into said reacting medium is carried out in a very efficient way due to the large interfacial surface area for mass transfer, turbulent mixing and relatively long residence time generated therein;
• (d) contacting the gas stream exiting each individual gas-atomized liquid contact zone with demisting means to agglomerate and remove entrained droplets from the gas stream before the gas stream passes to the next such zone and out of the outlet end;
• and
• (e) discharging a clean gas stream from the outlet end of the conduit,
• said solute gas being selected from the group consisting of sulfur oxides, gaseous bleach plant emissions comprising chloride and/or chlorine dioxide, odiferous components, acid gas streams, NO.sub.x gases and at least one VOC.