Has anyone injected SBS sodi8um bisulfate for SO3 reduction?
Has anyone injected SBS sodi8um bisulfate for SO3 reduction?
(OP)
Just curious if anyone has dealt with this, and what results you got with reductions of SO3 on a COAL fired power plant. And the affects on the equipment at the plant , if any.
Thanks
Jack
Thanks
Jack





RE: Has anyone injected SBS sodi8um bisulfate for SO3 reduction?
I am looking for information on the same subject, but for an oil-fired boiler (2.5% sulfur). See my thread July 24, 2003 in this forum. We are investigating alkaline injection alternatives to control opacity and backend corrosion caused by the conversion of SO3 to H2SO4.
I have received some information on SBS injection at three coal-fired sites, including system descriptions, results, costs, etc. I am interested in learning more though, including reagent availability, costs, and deposition issues. If you are interested in an information exchange, please let me know. I will check this thread for a response.
RE: Has anyone injected SBS sodi8um bisulfate for SO3 reduction?
Dick Kersey
Orenda Technologies, Inc.
RE: Has anyone injected SBS sodi8um bisulfate for SO3 reduction?
But there are other considerations to think about in the EPRI report. The duct pluggage is one. Nozzle pluggage is another item, especially if the SBS is injected ahead of the air heater. A sputtering nozzle will plug the air heater. The nozzles will need a lot of cleaning to keep the spray pattern right.
Since this is a slurry, there is pump maintenance. So there is additional costs to think about besides the annual license fee.
Also you will want to find alternate sources for the material. If you get locked into one supplier, they will control you.
RE: Has anyone injected SBS sodi8um bisulfate for SO3 reduction?
Elemental S can be used in conjunction with feed of dibasic acid (DBA) to enhance scrubber performance.
You do have to be careful to avoid overfeed of the elemental sulfur because it changes the settling characteristics of the CaSO3 hemihydrate in the waste treatment system so that it settles more like CaSO4 dihydrate which can result in damage to the rakes in the primary clarifer and the thickner by torque overload if your operators aren't on top of the situation.
RE: Has anyone injected SBS sodi8um bisulfate for SO3 reduction?
RE: Has anyone injected SBS sodi8um bisulfate for SO3 reduction?
FGD systems that are not inhibited or forced oxidized will have about 25% of the CaSO3 oxidized to CaSO4 which causes the scaling problem. If you can keep the CaSO4 below 15% in the scrubbing liquor you can minimize CaSO4 scaling in the absorber vessels. Another plus is the CaSO3 crystals grow larger and improved settling and dewatering has been observed in the FGD waste treatment system.
The S reaction efficiency depends on the residence time in the mill storage tank, absorber vessels and FGD waste treatment system. Any unreacted sulfur will leave with the solids.
Unfornately, I have not been able to readily lay my hands on the papers that were published. They are buried in my files and I have not found them today. This was first described in the late 1980's as the building boom was winding down on large coal fired power projects. As soon as I locate them I will post the chemical reaction equations here. My brain has purged the chemical reaction equations since FGD technology is not my primary area of practice.
RE: Has anyone injected SBS sodi8um bisulfate for SO3 reduction?
The working temperature could be considered a drawback, because it takes away plume buoyancy and brings the remaining pollutants to ground more easily if not reheated.
I was under the impression that both calcium salts are problematic in the final separation stage. CaSO3 would tend to form crystals that are small and flat plates, good at trapping and retaining water; if the cake consistency is that of a toothpaste it wouldn't be acceptable for landfills. Whilst CaSO4 forms larger and rounder crystals much easier to settle and filter.
RE: Has anyone injected SBS sodi8um bisulfate for SO3 reduction?