Caustic scrubber

None at present, but could use a waste heat boiler or afterburner, followed by a caustic scrubber for hydrochloric acid generated by combustion... 

In a number of applications liquid pumparound sections are installed. Such sections are used in caustic scrubbers where only a small addition of... 

Caustic scrubber systems should be installed to control chlorine emissions from condensers and at storage and transfer points for liquid chlorine. 

Total feed from caustic scrubber Hydrogen addition First-stage fresh feed First-stage recycle Second-stage fresh feed Second-stage recycle Product gas... 

The high temperatures ensure that inputs like MPW are effectively destroyed. Acidic substances such as HCl and SOx are neutralised by the alkali raw materials, which act in fact as a caustic scrubber. Metals are bound in the clinker or in the fly ash. Fly ash is captured with an electrofilter and subsequently added to the clinker. In general, no other flue gas cleaning is applied. 

In the process shown in Figure 10-9 the phosgene is fed from the container through a valve into a fritted glass bubbler in the reactor. The reflux condenser condenses aniline vapors and returns them to the reactor. A caustic scrubber is used to remove the phosgene and HC1 vapors from the exit vent stream. The complete process is contained in a hood. 

This chapter has therefore shown that cost minimisation of the treatment of hypochlorite effluent streams is achieved only through consideration of a wide range of process alternatives. The optimal solution for a given plant is dependent on a number of aspects, which include not only the rate and concentration of the stream as well as its required exit concentration, but also the configuration and operational mode of the caustic scrubber and any existing treatment system. 

Dichlorophenoxyacetyl chloride i4)was prepared by addition of 110.0 g (0.498 moles) of 2,4-dichlorophenoxyacetic acid in 250 ml of benzene and 7 ml of N,N-dimethylformamide (DMF) into a one liter, 3-necked roundbottomed flask equipped with mechanical stirrer, addition funnel, thermometer and condenser connected to a caustic scrubber. After heating to reflux, a solution of... 

Dichloropropionyl chloridefiS was prepared by charging a two liter, 3-necked, roundbottom flask equipped with mechanical stirrer,thermometer, addition funnel, and condenser connected to a caustic scrubber with 250 g of 2,2-dichlorophenoxyacetic acid in 500 ml of chloroform and 10 ml of DMF. The mixture was refluxed for one hour, followed by the addition of 328 g of thionyl chloride over a period of one hour. The mixture was refluxed for two additional hours. After removal of excess thionyl chloride and solvent, the crude product was vacuum distilled yielding 210 g of the acid chloride (b.p. 75°C 20 mm). 

The liquid discharges from the anolyte circuit, catholyte circuit, NOx reformer, and caustic scrubber were sampled and analyzed for metals and organics. At the time this report was prepared, not all of the data were available to the committee. As noted in the Demo II test report, the Army has concluded that the characterization of the products from agent and propellant destruction showed that most hazardous intermediates were encountered at relatively low levels that could be effectively destroyed with additional treatment steps (NRC, 2001b). 

Fresh monomers often have inhibitors added to them while in storage to prevent premature polymerization. These inhibitors and any water that is present in the raw materials must be removed by caustic scrubbers and fractionating drying columns to provide the solution process with the high purity and anhydrous materials needed. The purified solvent and monomers are then blended into what is termed the mixed feed, which may be further dried in a desiccant column. 

Compounds containing sulfur and cyanide become a potential source of air pollution when treated with this system. A caustic scrubber may be required to capture the combustion products of these compounds if sulfur and cyanide levels are high enough to exceed health and safety or applicable air quality standards. Metals that are not particularly volatile are not likely to be treated effectively by the TDS. Plastic materials are not recommended for treatment since their decomposition products could cause plugging or foul surfaces. 

Method A AsF3 and SbCl5 were mixed in amounts indicated in Table 1 and placed in a 3-necked flask equipped with a stirrer, reflux condenser, and thermometer. The haloalkane was then added and the mixture was quickly heated to gentle reflux in a water bath and held under these conditions for 2-4 h, after which time it was cooled and poured into dil HC1. The organic layer was separated, washed with 1 % aq NaOH (x 2) and H20, dried (CaCl2), and fractionated. When the product had a bp below rt, the reflux condenser was connected to a cold trap (— 78 CC). The condensate in the trap was evaporated through a caustic scrubber and recondensed. 

Overhead from the chlorinator is scrubbed to remove excess chlorine in two vessels in succession which employ water and 5% caustic solution, respectively. The water from the first scrubber is used in the chlorine solution tower. The caustic is recirculated in order to provide adequate wetting of the packing in the caustic scrubber fresh material is charged in at the same rate as spent material is purged. Following the second scrubber, propylene dichloride is recovered from the gas by chilling it. The spent gas is recycled to the chlorinator in the required amount, and the excess is flared. 

Caustic scrubbers 5 Nal 1 NaI03 Insoluble or iodide iodate... 

A multistage compressor, driven by a steam turbine, compresses the cooled gas. LP and HP condensates are stripped in two separate strippers where medium gasoline is produced and part of the C3+ cut is recovered respectively. A caustic scrubber removes acid gases. 

Application To oxidize sodium sulfide (Na2S) component in the caustic scrubber effluent of olefin plants with air using wet air oxidation (WAO) process developed by Nippon Petrochemicals Co., Ltd. (NPCC), the license being available from Toyo Engineering Corp. (TEC). 

The off gases from the Thorex waste pass through a caustic scrubber to remove the oxides of nitrogen prior to being combined with the Purex waste off-gases. This step is necessary since ammonia is evolved from the Purex waste and the combination of gaseous ammonia with oxides of nitrogen forms ammonium nitrate which sublimes on the filter media... 

As it had been previously demonstrated (by means of caustic scrubbers) that even a substantial reduction of the nitrogen dioxide present in outside air did not have a gross effect on its oxidant-forming ability, these experiments appeared to be largely of academic interest. A possible connecting link was nitric oxide, but its known rate of oxidation to nitrogen dioxide is slow and its presence in outside air had not been established. 

It is recommended that any plant which makes or uses phosgene in large quantities should be provided with two separate scrubber systems. A fume scrubber (to handle low phosgene concentrations diluted with a large volume of inerts) and a caustic scrubber (to handle higher phosgene concentrations). The fume scrubber is a general suction service for... 

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