Alkali Scrubbers

The gypsum produced by the alkali scrubber is sold as an agricultural supplement or soil conditioner to California farmers. It is generated at a rate of 10 tons/day and sold for 5 per ton.1... 

Place in halogenated solvent disposal container for disposal by burning in a furnace with afterburner and alkali scrubber.6... 

A wet alkali scrubber is generally employed to scrub acidic impurities from the noncondensable gas stream. The gaseous, water-soluble inorganic compounds are removed by scrubbing the noncondensable pyrolysis gas with an alkaline aqueous stream. In the scrubber, desulphurization and/or denitrogenation and/or dechlorination occurs. Most of the acidic gases such as HCl, SO2, SO3, H2S, etc. resulting from pyrolysis are absorbed in the scrubber. 

The phosgene storage area should be continuously vented to alkali scrubbers. 

Fig. 5 Flow diagram of the dual-alkali scrubber process, using lime to regenerate the sodium alkali. The clarified liquid from the thickener contains dissolved calcium sulfate, which would produce calcium carbonate scale in the scrubber when it contacts the carbon dioxide in the flue gas. It is therefore precipitated in the softening reactor by a combination of carbon dioxide and sodium carbonate, and the resulting calcium carbonate precipitate is removed by the hydrocyclone.

In the halogen mode, the alkali scrubber is removed from the outlet end of the nickel tube, and the electrolyte solvent is -propanol. The conductivity due to H of the HX is detected. The ionization of the other reaction products are suppressed by the w-propanol electrolyte. 

Natural gas from a gas well can be passed through an alkali scrubber to remove H2S gas and the alkali solution in the scrubber fed to an electrolyzer to recover caustic soda as catholyte and to precipitate sulfur in the anode compartment together with the generation of hydrogen gas.157... 

SPILL CLEAN-UP Absorb small spills with paper towels, place in hood to evaporate, then bum the towels material may also be dissolved in a combustible solvent and sprayed into furnace equipped with afterburner and alkali scrubber. 

DISPOSAL AND STORAGE METHODS pour onto sodium bicarbonate or sand-soda ash mixture and dump in closed incinerator with afterburner dissolve in flammable solvent and spray in incinerator equipped with afterburner and alkali scrubber storage should be in tightly closed containers keep from contact with water, alkali, and oxidizing materials. 

Providing a continuously operating alkali scrubber for SCSA plants. 

The stringent air pollution control laws in almost all countries have made it essential to provide alkali scrubbers after the FAT to remove the acid nust particles and unconverted SO2 from the stack gases. 

The following variants of the alkali scrubbers were used ... 

FAT alkali scrubber circulation pump failure during plant start-up or after a long shutdown Release of acid mist, unconverted SO2 and unabsorbed SO3 to the atmosphere Air blower and sulfur pump should trip automatically... 

Failure of alkali scrubber (either failure of scrubbing liquor circulation or complete... 

SO3 bearing gases for sulfonation about 90-95% of the SO2 fed to the converter is converted to SO3 by the end of the third pass. The gases exiting from the third-pass thus contain upto 9.8-10% SO3 and hence can be used for sulfonation of hnear alkyl benzene (LAB) for the detergent industry by providing some additional equipments. The unconverted SO2 can be scrubbed with alkali scrubber after the sulfonation plant. 

Apart from the benefits of the high pressure mixing of SO3 with water to produce sulfuric acid, the proposed cold process for the manufacture of sulfuric acid has also been conceived to avoid the complexity of requiring a sulfur furnace and the related heat recovery system, the multipass static converter, counter current heat exchangers, the interpass absorption tower (IPAT), drying tower (DT), final absorption tower (FAT), mist eliminators, acid coolers, and alkali scrubber. The resulting plant is, as a result, of much lower cost in equipment and land use. 

Improper absorption of SO3 and acid mist in absorption tower Unabsotbed SO3 and acid mist in exit gases Provision of candle demistea and alkali scrubber aftra final absmption tower Online monitraing of SO3 and acid mist in exit gases with alarm... 

Provide audio visual alarms in control room for drawing attention of operators towards such events. These are likely to disturb the conversion of SO2 to SO3 Strict instructions shall be given in operating manuals. Alkali scrubbers for tail gases shall be kept running always with proper alkali make-up. 

Exit gases from absoibta contain nitrogen oxides, HNO3 mist Enviromnental pollution Exit gas analyser and alkali scrubber for exit gases ... 

Escape of CI2 or HCl from tail gas scrubber Can be dangerous Provide alkali scrubbers, exit gas analysers, and gas detectors in working areas Provide installed spare circulation pumps for scmbber install gas detectors for CI2 and HCl and alarms... 

Manufacture of sulphuric acid by the modified 3 + 2 DCDA process (having three catalyst passes before interpass absorption tower and two passes after it) with caesium-promoted catalyst resulted in better conversion of SO2 to SO3 and negligible escape of SO2 from exit gases. An alkali scrubber for tail gases was provided for taking care of this. 

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