Scrubber vapour

Appropriate gas/vapour/fume/pressure venting, e.g. flame arrestors, scrubbers, absorbers, stacks Ensure adequate natural or forced general ventilation of the storage area Provide adequate, safe lighting... 

Gases or vapours that are water soluble or miscible or that are only soluble or highly reactive in other agents Absorption with multiple surface contact by atomizing liquid with spray nozzle or jet impaction Crabtree ozone analyser or midget venturi scrubber Water, acid, or alkali 5-25 60-100 Venturi scrubber satisfactory if dust is present Atomizer absorber will plug... 

Continuing further with the recovery aspects from coke oven gas reference may be drawn to the recovery of light oil (crude benzol). In a typical process used, the coke oven gas (from which benzol is to be recovered) after removal of tar, ammonia etc. is passed through the benzol scrubber where the benzol vapours are scrubbed by wash oil flowing countercurrent to the gas. Benzolised wash oil is then pumped to the recovery section where the crude benzol, absorbed in the wash oil is stripped off by steam. The steam vapour mixture, com-... 

Pressure control will be necessary for most systems handling vapour or gas. The method of control will depend on the nature of the process. Typical schemes are shown in Figures 5.17a, b, c, d (see p. 230). The scheme shown in Figure 5.17a would not be used where the vented gas was toxic, or valuable. In these circumstances the vent should be taken to a vent recovery system, such as a scrubber. 

Fires inside wood-packed benzene scrubbers in coke oven gas plants were attributed to saturation of the wood with naphthalene, and vapour-phase oxidation of the latter to phthalic anhydride, which participates in exothermic free radical chain reactions. 

Vacuum sublimation is a development of simple sublimation, which is particularly useful if the pressure at the triple-point is lower than atmospheric, where the transfer of vapour from the vaporiser to the condenser is enhanced by the increased driving force attributable to the lower pressure in the condenser. Iodine, pyrogallol, and many metals have been purified by vacuum sublimation processes in which the exit gases from the condenser are usually passed through a cyclone or scrubber to protect the vacuum equipment and to minimise product loss. 

The process is conducted in a vertical steel apparatus filled with the catalyst suspended in liquid ethylchloride. This mixture is treated by hydrogen chloride and ethylene, while the contents of the reactor are intensively agitated. With the formation of ethylchloride, the volume of the liquid in the apparatus grows therefore, the surplus of ethylchloride is constantly withdrawn from the reaction zone. Liquid ethylchloride, leaking from the reactor with catalyst particles, as well as dissolved hydrogen chloride, is vapourised, washed in a scrubber with a 10% alkaline solution, dried with sulfuric acid and condensed. The reaction gases, laden with ethylchloride vapours, are washed with water from hydrogen chloride, dried with concentrated sulfuric acid and sent into an absorber, where ethylchloride is extracted with kerosene. By distillation and subsequent condensation, ethylchloride is extracted from the obtained solution. 

There is a single vent stack in the plant. The stack gases are treated in a benzene scrubber to remove benzene vapours prior to incineration or other means of treatment290. 

A wet scrubber, in which a solution of ammonium sulphate circulates, cools the gas and causes most of the water vapour to condense, whilst at the same time it absorbs any remaining contaminants in the gas, primarily ammonia. The condensate is cleaned by physical and biological treatment. 

The TDT-3R (a)priinaTy desorption chamber, (b)condensation or burning of pyrolysis gas vapours and c)non destructive APCD off gas scrubber are separate devices, whereas (l)treated solids, (2)condensate residuals, (3)APCD residuals, (4)organic air emission, (S)metal air emission, (6)acid gas emission treatment are according to all the relevant comprehensive U.S. and E,U. regulatory requirements for Operational Control, Residuals and Air Emission Parameters. 

Prepare hydrochloric acid derivative(s) as follows. Place a small beaker containing the acid on a hot-plate stirrer inside a fume cupboard and heat gently. Sample the acid atmosphere by drawing vapour through a Dreshler bottle, containing scrubber solution (10 ml), connected to a suitable pump unit. Sample for approximately 30 min. Remove scrubber solution and... 

Determination of the concentrations of a hydrochloricInitric acid in a mixture. Prepare an external standard mixture for gas chromatographic analysis as follows. Add nitric acid (0.5 g) and hydrochloric acid (0.1 g) to dichloromethane (10 ml) followed by scrubber solution (10 ml). Stir for 15 min then dilute to 50 ml with dichloromethane. Generate a mixed acid vapour environment by placing a small beaker containing the acids in equal volume on a hot-plate stirrer inside a fume cupboard and heat gently. Sample the atmosphere as detailed in (a) but for 10 min. Note the volume sampled. Make 0.5 pi duplicate injections of standard and sample and hence determine the concentrations of the acids in the sample by direct comparison with peak areas of the standard (external standardisation). From this data and the volume of atmosphere sampled determine the short term exposure limit. By comparison with HSE recommended limits would this atmosphere pose a hazard (See Figures 9.15-9.17.)... 

As shown in Figure 4.21, the salt that is formed from tertiary amine (e.g. DMEA, DMIA and triethanolamine (TEA)) in the acid scrubber, and the scrubbing acid (e g. sulphuric acid) are retransformed by reaction with a strong base (e.g. caustic soda solution), thereby forming free amine and e.g. sodium sulphate. The amine is expelled with water vapour and is then cleaned and concentrated in a column, to an extent that allows it to be re-used. The sodium sulphate solution (together with polluted scrubbing solution) can be recovered or may be disposed of. 

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