Flue scrubber solution

Fig. 8-21. Analysis of inorganic anions in the scrubber solution of a flue gas desulfurization plant. - Chromatographic conditions see Fig. 8-16 injection 50 pL sample (1 100 diluted).

Fig. 8-22. Analysis of chromium(VI) in a scrubber solution from the flue gas desulfurization. — Separator column IonPac CS5 eluent 0.002 mol/L pyridine-2,6-dicarboxylic acid + 0.002 mol/L Na2HP04 + 0.01 mol/L Nal + 0.05 mol/L NH4OAC + 0.0028 mol/L LiOH flow rate 1 mL/min detection photometry at 520 nm after reaction with 1,5-diphenylcarbazide injection 50 pL sample (1 10 diluted).

Fig. 8-23. Analysis of ammonium in a scrubber solution from flue gas desulfurization. - Separator column IonPac CS2 eluent 0.03 mol/L HC1 flow rate 1 mL/min detection fluorescence after reaction with OPA injection 50 pL sample (1 5 diluted).

Fig. 8-26. Analysis of nitrite in a scrubber solution from flue gas denitrification. - Separator column IonPac AS3 eluent 0.0028 mol/L NaHC03 + 0.0022 mol/L Na2C03 flow rate 2.3 mL/min detection suppressed conductivity injection 50 pL sample...

In this reaction, diphenylcarbazide is oxidized to diphenylcarbazone, while at the same time chromium(VI) is reduced to chromium(III), which forms a chelate complex with diphenylcarbazide. Like the metal-PAR complexes, it is red-purple colored and thus may be photometrically detected at 520 nm. As already mentioned, chromate separation is performed by means of anion-exchange chromatography. The high selectivity of this technique is revealed in Figure 8.51, which shows the analysis of chromium(VI) in a flue gas scrubber solution. Despite high contents of chloride and sulfate, chromium(VI) can be determined in this sample without any interferences. 

Figure 8.51 Analysis of chromium(VI) in a flue gas scrubber solution. Separator column lon-Pac CS5A eluent 2 mmol/L pyridine-2,6-dicarboxylic acid + 2 mmol/L Na2HP04 +10 mmol/L Nal +50 mmol/L NH4OAC flow rate ...

Figure 10.119 Analysis of inorganic anions in volume 50 (iL sample flue gas scrubber solu-a flue gas scrubber solution. Separator column Son, 1 100 diluted peaks 1 lOmg/L fluoride lonPac AS4 eluent 2.2 mmol/L Na2C03 + 25 (1), 650 mg/L chloride (2), 1300 mg/L nitrate...

Today, the determination of sodium, potassium, and magnesium in flue gas scrubber solutions is carried out with a weak acid cation exchanger utilizing suppressed conductivity detection (Figure 10.120). However, ammonium present at low concentration cannot be determined in the same run under these... 

Figure 10.121 Analysis of dithionate in a scrubber solution from flue gas desulfurizafon. Separator column lonPac NS1 (10 pm) eluent 2 mmol/L TBAOH +1 mmol/L Na2C03/MeCN (85 15 v/v) flow rate 1 mlVmin detection ...

Thus, the retention difference between fluoride and chloride, which is less than 2 minutes under the same conditions on an AS4A column, may be expanded to more than 20 minutes with the CarboPac PAl. Figure 3-122 illustrates an example of the baseline-resolved separation of various monocarboxylic acids, which would elute as one peak close to the void volume when using an AS4A column. Monocarboxylic acids are relevant in many of today s analysis problems this procedure provides an elegant solution. Amidosulfonic acid, for example, is one of the many components in flue gas scrubber solutions from desulfurization devices, which require frequent analysis. 

Fig. 9-63. Cation analysis in a flue gas scrubber solution. -Separator column lonPac CS12 eluant 20 mmol/L methanesulfonic acid flow rate 1 mL/min detection suppressed conductivity injection 25 pL flue gas scrubber solution.

These scrubbers have had limited use as part of flue gas desulfurization (FGD) systems, but the scrubbing solution flow rate must be carefully controlled to avoid flooding. When absorption is used for VOC control, packed towers are usually more cost effective than impingement plate towers (discussed later). 

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