Method for removing mercury from a gas stream using iodine-doped dilution gas
A method for removing mercury, and in particular elemental mercury, from a fluid stream by blending the fluid stream with a second stream comprising iodine. The blended stream is then passed through at least one filter, which is capable of removing oxidized forms of mercury from gas streams.
1. A method for removing mercury from a gas stream, the method comprising:
providing a first gas stream comprising mercury;
providing a second gas stream comprising iodine;
blending the first gas stream with the second gas stream to provide a blended gas stream; and,
removing the mercury from the gas stream by passing the blended gas stream through at least one filter, the filter including a polyethersulfone surface.
2. A method according to claim 1 wherein the step of passing the blended gas stream through the at least one filter removes substantially all of the mercury from the blended gas stream.
3. A method according to claim 1 wherein the at least one filter further includes a filter selected from the group consisting of a carbon-impregnated filter, a bio-membrane filter and a resin-impregnated filter.
4. A method according to claim 1 wherein the first gas stream comprises elemental mercury.
5. A method according to claim 1 wherein the first gas steam comprises oxidized forms of mercury.
6. A method according to claim 4 wherein the first gas steam comprises oxidized forms of mercury.
7. A method for removing mercury from a gas stream, the method comprising:
providing a first gas stream comprising mercury and at least one other oxidizable compound;
providing a second gas comprising iodine;
blending the first gas stream with the second gas to provide a blended gas stream and to oxidize at least a portion of the mercury;
adding at least one anti-oxidants to the first gas stream to inhibit oxidation of the at least one other oxidizable compound; and,
removing the oxidized mercury from the blended gas stream by passing the blended gas stream through at least one filter.
8. A method according to claim 7 wherein the step of adding anti-oxidants to the first gas stream is performed before the step of blending the first gas stream with the second gas stream.
9. A method of quantitatively removing mercury comprising the steps of:
providing a first gas stream comprising vapor-phase mercury;
introducing vapor-phase iodine into the first gas stream;
reacting at least a portion of the vapor-phase iodine with a first portion of the mercury in the first gas stream to form at least one mercury-containing solid; and,
removing the at least one mercury-containing solid from the first gas stream
removing unreacted vapor phase mercury from the first gas stream by contacting the first gas stream with a polyethersulfone surface.
10. A method according to claim 9 wherein the step of introducing vapor-phase iodine into the first gas stream includes the steps of:
providing a second gas stream comprising iodine vapor; and,
combining the first and second gas streams.
11. A method according to claim 9 wherein the step of introducing vapor-phase iodine into the first gas stream includes the steps of:
providing a second gas stream;
providing solid iodine; and,
contacting the second gas stream with the solid iodine and vaporizing at least a portion of the solid iodine.
12. A method according to claim 11 wherein the step of providing solid iodine includes the step of providing particulate iodine.
13. A method according to claim 11 wherein the step of contacting the second gas stream with the solid iodine and vaporizing at least a portion of the solid iodine comprises providing the second gas stream at a pre-determined temperature selected to vaporize the solid iodine at a pre-selected rate.