Scrubber solution tests

T in the contaminated soil to the corresponding chlorophenols at molar equivalents. In addition to using prepared scrubber solutions, solvent spiked with 2,4-D and 2,4,5-T, the corresponding chlorophenols, or 2,3,7,8-TCDD was used for baseline photolysis tests. 

Table VI. Initial vs Final Concentration of Selected Compounds in Scrubber Solution from MCBC Pilot Photolysis Tests...

In Appendix D of the AEA Eiraft Final Report (AEA, 2000), AEA gave a detailed calculation of the DRE (e.g.. Table D-11 for DMMP), and it is clear that AEA calculated the discharges based on the flow rate of gas through the scrubber, the concentration observed in the scrubber off-gas, and the duration of the run. Post-test sampling of the anolyte, catholyte, and dilute and concentrated nitric acid and caustic scrubber solution was used to determine the amount remaining in the plant. 

The steel fiber filter and the Venturi scrubber were tested under similar conditions (Dickinson et al., 1990 McCormack et al., 1990). The decontamination factors for manganese and cesiiun with the steel fiber filter were on the order of 10 for particle iodide, a retention on the same order of magnitude was measured, whereas the decontamination factor for total iodine was only on the order of 10 , probably due to a partial decomposition of Csl or to an incomplete consumption of HI during the generation of the Csl aerosol. The tests performed with the Venturi scrubber showed aerosol decontamination factors of more than 10 here also, the iodine decontamination factor was lower by a factor of about 10. More than 99% of the retained matter remained in the scrubber solution, less than 1% in the steel fiber filter, which is installed downstream. In contrast with the solid-state filters, in the Venturi scrubber no problems resulted from the aerosol load of the retention system. 

By the above pi ocedure it is claimed that 1 mg formaldehyde in 10 cc of, test solution can be measured with an accuracj of 1 per cent. With smaller quantities the error increases rapidly so that sufficient ah- should always be scrubbed to absorb at least 1 mg CH<>0 per 10 cc of scrubber solution. The accuracy of the method is not impaired by the presence of methanol, acetic acid, and bromine in the air to be tested. Errors due to acetone may be eliminated as indicated in the procedure. Formic acid should be Without effect, since it does not interfere i ith the iodimetric procedure for formaldehyde analysis (pages 259-261). 

The foam also contains decon solution.. . . Then the secondary tent is placed over the primary and is hooked up to the Air Pollution Control (APC) equipment. The scrubber, the first piece of the APC, will contain a NaOH solution. After use, the waste liquid will be disposed of and will consist of the NaOH, some Oil of Wintergreen Residue [Methyl salicylate, an agent simulant used in testing], some explosive residue, and decon agents in the foam. 

Prior to testing, 3.0-3.5L of scrubber feed solution are saturated overnight with approximately 10 g of the limestone of interest. Saturation is accomplished at the temperature at which the run is to be performed. Ten grams of the limestone are ground and sized to the desired mesh. Pictures were taken using an optical microscope to document the size distribution. 

Identification of an efficient metal chelate for optimum absorption of NO requires knowledge of the thermodynamics and kinetics of the coordination of NO to various metal chelates. Knowledge is also needed of the kinetics and mechanisms of the reaction between nitrosyl metal chelates and absorbed SO2 in solution to calculate the regeneration rate of metal chelates and to control the products of reaction by adjusting the scrubber operating conditions. Not much of this information is available in the literature, although several ferrous and cobalt chelates have been used as additives for testing in bench-scale wet flue gas simultaneous desulfurization and denitrification scrubbers. 

The first pilot scrubber tests were conducted using simulated flue gas to establish the feasibility of sulfur dioxide s reacting with sodium carbonate solutions and slurries in a spray dryer. Subsequent tests were conducted at the Mohave generating station, where a 5-ft diameter modified spray dryer was used to test sulfur dioxide removal from a side stream of flue gas from this coal-fired power plant (Figure 4). The spray dryer had been in operation for over 20 yr in various drying applications prior to modification to a sulfur dioxide scrubber. It was used in over 100 tests at Mohave without a single operational problem. 

One of the primary reasons that the spray dryer-scrubber is able to achieve excellent sulfur dioxide removal with such low liquid-to-gas ratios is the small size of the droplets produced by the high speed centrifugal atomizer. This type of atomizer also has an easily controlled turndown capability which is a desirable feature that has been demonstrated in the pilot tests. As gas flow decreases, the amount of sodium carbonate solution can be decreased in direct proportion without interfering with sulfur dioxide removal efliciency. The atomizer actually produces finer droplets at the lower liquid flow rates. This appears to compensate for any gas-liquid mixing problems that could impair performance. 

Two additional steps were taken to minimize corrosion downstream of the glycol dehydrator unit. One was the use of a product-gas scrubber to minimize glycol entrainment in the gas stream, and the other was the use of a second inhibitor that was added to the dried-gas stream. This material was of the polyethanolrosinamine-type consisting of 70% solution in isopropyl alcohol of a mixture of 90% ethoxylated rosinamine (II moles ethylene oxide with each mole of rosinamine) and 10% free rosinamine. This inhibitor was injected at the rate of 0.1 gal/day for a gas volume of 60 MMsef/day. As a result of the above measures, the corrosion rate of coupons suspended in the dried-gas line decreased from almost 30 mils ear to as low as 0.2 mil/year during about 4 years of testing. 

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