Scrubber feed composition

The next day the filtered solution is then used as the initial charge to the reactor. In this way, the initial reactor composition will be approximately the same in the beginning as during the run. The pH controller is then set to the desired value. The pH controller is used to meter scrubber feed liquor (pH 2) into the reactor to maintain a constant reactor pH. After the stirring rate has been set and the desired temperature reached, 10.00 g of sized limestone are added to the reactor. 

Composition of aqueous feed to first scrubber <8ppmwCE (7.21)... 

A simple water scrubber is used as a preliminary stage to the Prism separators to remove all but traces of the methanol from the purge gas which might otherwise damage the membrane material. In order to avoid residual water condensation in the membrane system, the feed gas is then heated to some 10 °C above the water dew point and then fed to the Prism separators. The permeate gas, i.e. the gas that has permeated the membrane, consists of a mixture containing some 90% of the hydrogen in the feed gas and has the following composition ... 

Using the roasters as the addition point carries its own problems. If too much of the halides is eliminated in the roasters, we will need to increase the scrubber solution bleed to minimize corrosion. Corrosion will also occur in the gas handling system, especially where the temperature falls below the condensation point of hydrochloric and hydrofluoric acids. The heat balance difficulties in the roasters is atfributable to the increased feed rate. Heat removal achieved by the addition of moist oxide offsets the use of direct injection water in the roasters. The composition of the oxide material also poses a problem as roaster feed. Because the oxides... 

The design procedure for a packed-gas scrubber parallels that of the countercurrent staged cascade. We start by fixing the point (X2, Y2) representing the compositions at the top of the column. Y2 denotes the prescribed effluent concentration and X2 the purity of the solvent. A line of slope LJis next drawn through that point and extended to the level of the feed concentration Yj. The slope is usually set at a value in the range 1.2 to 1.5 LJGs)Mm-... 

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