Methods and systems for inhibiting crystalline buildup in a flue gas desulfurization unit

A method for inhibiting crystalline buildup in a flue gas desulfurization (FGD) unit, the method comprising:

• providing an FGD unit configured for desulfurization of a flue gas, wherein the FGD unit comprises:
• a vessel with a flue gas inlet and a flue gas outlet and a liquid reservoir containing a desulfurization agent;
• a recirculation/spray system configured to desulfurization agent through the FGD unit;
• and
• one or more contact surfaces in the vessel configured for contacting the flue gas and the desulfurization agent recirculated from the reservoir, wherein the one or more contact surfaces include a perforated plate;
• preparing an inoculum that comprises a bacterial strain comprising at least one of Bacillus subtilis or Bacillus chitinosporus, the bacterial strain being adapted to grow in the FGD unit and to form a biofilm on the perforated plate to inhibit formation of calcium sulfite and sodium sulfite crystals thereon, wherein the inoculum has a selected volume and a selected bacterial cell density in a range of 0.01 weight % (wt %) to 10 wt %;
• and
• inoculating the FGD unit with a first amount of the inoculum the first amount being from 50 gallons to 200 gallons wherein the first amount of the inoculum has a bacterial cell density in the range from 0.01 wt % to 10 wt % such that the bacteria form a biofilm on one or more surfaces of the perforated plate so as to inhibit buildup of calcium sulfite and sodium sulfite crystals on the perforated plate;
• wherein the bacterial strain in the inoculum further comprises at least one of a bacterial, proteobacterial, or archaeal species selected from Rhodococcus, Pseudomonas, Clostridia, Burkholderia, Oceanospirillum, Neptunomonas, Alcanivorax, Acetobacter sp., Acidiothiobacillus sp., Acetobacterium sp., Clostridia sp., Pseudomonas sp., Halobacteria, Halococcus, Chromohalobacter, Methanosarcina sp., Methanococcus sp., Acetobacterium, sp., Clostridia sp., Pseudomonas sp., Micrococcus, Achromobacter, Flavobacterium, Bacterioides, Serratia, Alcaligenes, or Cellulomonas.

A method for inhibiting crystalline buildup in a flue gas desulfurization (FGD) unit, the method, comprising:

• providing an FGD unit configured for desulfurization of a flue gas, wherein the FGD unit comprises:
• a vessel having a flue gas inlet and a flue gas outlet and a first liquid reservoir containing a desulfurization agent;
• a recirculation/spray system configured to desulfurization agent through the FGD unit;
• and
• one or more contact surfaces in the vessel configured for contacting the flue gas and the desulfurization agent recirculated from the first liquid reservoir, wherein the one or more contact surfaces include a perforated plate;
• a second liquid reservoir containing the desulfurization agent, wherein the second liquid reservoir is fluidly connected to the FGD unit via a conduit and a pump, and wherein the second liquid reservoir is configured to replenish the desulfurization agent in the FGD unit;
• and
• a third reservoir configured to contain a selected bacterial strain that includes at least one of Bacillus subtilis or Bacillus chitinosporus adapted to grow in the FGD unit, wherein the third reservoir is coupled to the FGD unit via a conduit and a feed system, and wherein the third reservoir is configured for inoculating the FGD unit with the selected bacterial strain adapted to grow in the FGD unit to inhibit buildup of calcium sulfite and sodium sulfite crystals in the FGD unit;
• preparing an inoculum that comprises the at least one of Bacillus subtilis or Bacillus chitinosporus adapted to grow in the FGD unit and to inhibit formation of calcium sulfite and sodium sulfite crystals therein, wherein the inoculum has a selected volume and a selected bacterial cell density in a range of 0.01 weight % (wt %) to 10 wt %;
• placing the inoculum in the third reservoir;
• and
• inoculating the FGD unit with 50 gallons to 200 gallons of the inoculum, wherein the inoculum has a bacterial cell density from 0.01 wt % to 10 wt % such that the bacteria form a biofilm on at least the perforated plate so as to inhibit buildup of calcium sulfite and sodium sulfite crystals on the perforated plate.