Apparatus and method for exhaust gas pollution reduction
View Patent ↗A method for reducing pollution in exhaust gases and a system for treating exhaust gas are provided. The method includes the step of treating an exhaust gas stream with a treating fluid. In one application, the treating fluid is injected by spraying droplets into the exhaust gas stream. A system for treating exhaust gas includes a reagent, and a nozzle to spray the reagent into the exhaust gas stream.
1 . A system for treating exhaust gas streams from an industrial process, the system comprising:
a treating fluid comprising a reagent comprising one or more chelating agents, the chelating agents comprising a mixture of ethylenediaminetetraacetic acid and amino tris (methylene phosphonic acid);
at least one nozzle configured to communicate with an exhaust gas stream;
a particulate collection system;
wherein said at least one nozzle injects said treating fluid into said exhaust gas stream to form a combined stream before entering the particulate collection system, the one or more chelating agents interacting with one or more heavy metals in the exhaust gas stream through chelation or physical binding, to form one or more particulates;
wherein the nozzle produces droplets of the treating fluid having a size to maintain sufficient residence time for effective interaction with the one or more heavy metals in the exhaust gas stream; and
wherein the particulate collection system separates the one or more particulates comprising at least a portion of the one or more heavy metals from the combined stream by forming a particulate residue containing the one or more heavy metals in non-leachable form.
2 . The system of claim 1 , wherein said treating fluid further comprises at least one selected from the group of a surfactant, a dispersant, and a hyperdispersant to enhance dispersion of the chelating agents within droplet phase and facilitate interaction with gas-phase of the one or more heavy metals.
3 . The system of claim 1 , wherein the treating fluid further comprises a solvent comprising propylene glycol wherein the solvent maintains droplet stability and promotes residence time of the treating fluid in the exhaust gas stream.
4 . A method for treating exhaust gas streams from an industrial process, the method comprising:
providing an exhaust gas stream;
providing a reagent comprising one or more chelating agents, the one or more chelating agents comprising a mixture of ethylenediaminetetraacetic acid and amino tris (methylene phosphonic acid);
providing at least one nozzle configured to communicate with an exhaust gas stream, wherein the nozzle produces droplets of the treating fluid having a size to maintain sufficient residence time for effective interaction with one or more heavy metals in the exhaust gas stream;
providing a particulate collection system;
injecting the treating fluid into the exhaust gas stream through the nozzle to form a combined stream before entering the particulate collection system, the one or more chelating agents interacting with the one or more heavy metals in the exhaust gas stream through chelation or physical binding, to form one or more particulates; and
separating the one or more particulates in the particulate collection system comprising at least a portion of the one or more heavy metals from the combined stream by forming a particulate residue containing the one or more heavy metals in non-leachable form.