Stripping agent

If steam is used as stripping agent, either live steam or a reboiler can be used. The use of live steam increases the effluent volume. The volatile organics are taken overhead, condensed, and recycled to the process, if possible. If recycling is not possible, then further treatment or disposal is necessary. 

If air is used as stripping agent, further treatment of the stripped material will be necessary. The gas might be fed to an incinerator or some attempt made to recover material by use of adsorption. 

Science dealerships aren t the only places to get the stuff one needs. At those mega hardware stores one can find pure acetone, methanol, ethanol, toluene, methyl ethyl ketone, DCM(as a constituent of some stripping agents), sodium hydroxide in the form of lye, and some acids such as sulfuric and hydrochloric. These precious tools can be bought there cheaply and in great quantity. 

Recovery Process. Commercial processes depend on the oxidation of bromide to bromine. Most of the Hberated bromine remains dissolved in the brine. The brine is then stripped of bromine followed by recovery of bromine from the stripping agent. Subsequent purification by distillation is often a final step. 

The corresponding estimate of minimum stripping-agent flow rate for a stripper is obtained as... 

Three external MSAs are considered a solvent extractant (S2), an adsorbent S3), and a stripping agent (S4). The data for the candidate MSAs are given in Table 3.9. The equilibrium data for the transfer of the pollutant from the waste stream to the 7th MSA is given by... 

In the range of operating temperatures and compositions, the equilibrium relations are monotonic functions of temperature of the MSA. This is typically true. For instance, normally in gas absorption Henry s coefficient monotonically decreases as the temperature of the MSA is lowered while for stripping the gas-liquid distribution coefficient monotonically increases as the temperature of the stripping agent is increased. 

The extraction of styrene from polystyrene has also been studied by Biesenberger and Kessidis (1982). This study consisted of two sets of experiments. One set was conducted at atmospheric pressure, a pressure well in excess of the equilibrium partial pressure of styrene in the feed-stream, The stripping agent used was nitrogen. The other set was conducted at a pressure of 1 Torr, which was found, by visual observation, to be low enough for bubble formation and entrainment. 

Published experimental studies on devolatilization rates in twin-screw extruders fall into two categories studies conducted at pressures in excess of the equilibrium partial pressure of the volatile component in the feedstream using an inert gas as the stripping agent and those conducted at pressures lower than the equilibrium partial pressure of the volatile component. 

The beneficial effect that the introduction of water has on the extraction of ethylene from low-density polyethylene is shown in Fig. 18. The reduction in the exit concentration of ethylene is substantial, especially at the higher pressures, and dramatically illustrates the increase in mass transfer rates which results from the introduction of an immiscible stripping agent. 

Instantaneous molar flux of volatile component from nip Pressure in extraction zone Vapor pressure of stripping agent or fugitive component Initial gas pressure in bubble Vapor pressure of volatile component... 

Two-stage and multiple-stage vented extruders are commonly used to remove volatile components from molten resin streams prior to downstream processing. The vent ports can be open to the atmosphere, or they can be attached to elaborate vacuum systems. For very specialized systems, stripping agents such as water, nitrogen, and carbon dioxide can be added upstream of the vent, mixed into the resin stream, and then devolatilized in the vent area. This technique can be employed to remove difficult components or components at a higher rate from the resin. 

Figure 15.9 Schematic for a blister and gear mixing section. The blisters are used to adjust the specific rate of the process, and the gear mixer and second blister are used to distribute and disperse the stripping agent into the resin...

Uses Solvent for celluloid, cellulose acetate, fats, oils, waxes, nitrocellulose and resins wood preservatives rayon and artificial leather imitation gold leaf extraction of resins and waxes in antifreeze mixtures and hydraulic fluids laboratory reagent preservative for animal tissue dyeing mixtures stripping agent for textiles. 

Mixer and settler operations as in extraction above Stripping agent... 

Case study dichloromethane-free stripping agents ... 

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