Scrubbing aqueous

Stream Phase Feed Aqueous Scrub Aqueous Solvent Organic Total Residue Aqueous Extract Organic Total... 

Fieser s solution An aqueous alkaline solution of sodium anthraquinone -sulphonale (silver salt) reduced with sodium dithionite, Na2S204, and used as a scrubbing solution for partially removing O2 from, e.g., N2. 

Recovery of iodine hy action of sulfur dioxide on aqueous sodium iodate Hydrogenation of vegetable oils with gaseous hydrogen Desulfurization of gases by scrubbing with aqueous ethauolamiues... 

Example 3 illustrates the use of Eq. (14-8) for scrubbing chlorine from air with aqueous caustic solution. For this case one can make the simplifying assumption that y, the interfacial partial pressure of chlorine over the aqueous caustic solution, is zero owing to the rapid and complete reaction of the chlorine after it dissolves. We note that the feea gas is not dilute. 

Particulate emissions from zinc processing are collected in baghouses or ESPs. SO2 in high concentrations is passed directly to an acid plant for production of sulfuric acid by the contact process. Low-concentration SO2 streams are scrubbed with an aqueous ammonia solution. The resulting ammonium sulfate is processed to the crystalline form and marketed as fertilizer. 

Liquid-solid Slurry Suspension Aqueous effluent from fume scrubbing... 

The simplest way of removing hydrogen sulfide is to scrub the hydrocarbon mixture with an aqueous solution of a strong base, such as sodium hydroxide. The hydroxide reacts with the HjS, which is a weak acid, and the hydrogen sulfide removal is quantitative even in a single contact stage. Spent caustic from this operation cannot be regenerated economically. 

While ethyl chloride is one of the least toxic of all chlorinated hydrocarbons, CE is a toxic pollutant. The off-gas from the reactor is scrubbed with water in two absoiption columns. The first column is intended to recover the majority of unreacted ethanol, hydrogen chloride, and CE. The second scrubber purifies the product fiom traces of unreacted materials and acts as a back-up column in case the first scrubber is out of operation. Each scrubber contains two sieve plates and has an overall column efficiency of 65% (i.e., NTP = 1.3). Following the scrubber, ethyl chloride is finished and sold. The aqueous streams leaving the scrubbers are mixed and recycled to the reactor. A fraction of the CE recycled to the reactor is reduced to ethyl chloride. This side reaction will be called the reduction reaction. The rate of CE depletion in the reactor due to this reaction can be approximated by the following pseudo first order expression ... 

In a packed column, operating at approximately atmospheric pressure and 295 K, a 10% ammonia-air mixture is scrubbed with water and the concentration of ammonia is reduced to 0.1%. If the whole of the resistance to mass transfer may be regarded as lying within a thin laminar film on the gas side of the gas-liquid interface, derive from first principles an expression for the rate of absorption at any position in the column. At some intermediate point where the ammonia concentration in the gas phase has been reduced to 5%. the partial pressure of ammonia in equilibrium with the aqueous solution is 660 N/nr and the transfer rate is ]0 3 kmol/m2s. What is the thickness of the hypothetical gas film if the diffusivity of ammonia in air is 0.24 cm2/s ... 

Recent years, the authors have innovatively proposed a method by using the aqueous ammonia liquor containing hexamine cobalt (II) complex to scrub the NO-containing flue gases[6-9], since several merits of this complex have been exploited such as (1) activation of atmospheric O2 to a peroxide to accelerate the O2 solubility, (2) coordination of NO, as NO is a stronger ligand than NH3 and H2O of Co( II) complexes to enhance the NO absorption and (3), catalysis of NO oxidation to further improve the absorption both of O2 and NO. Thus, a valuable product of ammonium nitrate can be obtained. 

Liquid Liquid Liquid-gas Liquid-liquid Liquid-solid Solution Foam Emulsions Slurry Suspension Metal plating effluent spent acids wash-waters Detergent foam Oil-in-water (e.g. suds) water-in-oil Aqueous effluent from fume scrubbing... 

The number of fluorine equivalents (to toluene) was varied the gas and liquid flow velocities were kept constant to maintain the same flow pattern for all experiments. Liquid products were collected in an ice-cooled roimd-bottomed glass flask containing sodium fluoride to trap the hydrogen fluoride. The flask is connected to a cooling condenser to recover the solvent. Samples were typically collected for 1 h. Waste gases were scrubbed in aqueous 15% potassium hydroxide solution. Samples were degassed with nitrogen and filtered before analysis. 

After leaving the reactant zone, the product stream enters a 0.5 in diameter FEP tube cooled by either a salt-ice bath or acetone-carbon dioxide slush bath [16]. The gas mixture was scrubbed in a soda-Hme tower. Hydrogen fluoride was trapped by adding sodium fluoride to the reaction mixture or simply adding water. Then, the product solution was extracted with dichloromethane, washed with aqueous... 

Other important alternate electrochemical methods under study for pCO rely on measuring current associated with the direct reduction of CO. The electrochemistry of COj in both aqueous and non-aqueous media has been documented for some time 27-29) interferences from more easily reduced species such as O2 as well as many commonly used inhalation anesthetics have made the direct amperometric approach difficult to implement. One recently described attempt to circumvent some of these interference problems employs a two cathode configuration in which one electrode is used to scrub the sample of O by exhaustive reduction prior to COj amperometry at the second electrode. The response time and sensitivity of the approach may prove to be adequate for blood ps applications, but the issue of interfering anesthetics must be addressed more thorou ly in order to make the technique a truly viable alternative to the presently used indirect potentiometric electrode. 

To provide a more generalized picture for achieving separations by solvent extraction one can consider a number of possibilities, according to direction of transfer. Such possibilities are (i) pre-extraction (aqueous — solvent) (ii) extraction (aqueous — solvent), scrubbing (solvent —> aqueous) (iii) stripping/back extraction (solvent — aqueous) and (iv) solvent clean up (solvent —> aqueous — solvent). The direction of transfer has been shown in the parentheses of the four possibilities that have been listed. A reference to Figure 5.14 is relevant in this premise. 

Chlorine is to be removed from a vent stream by scrubbing with a 5 per cent w/w aqueous solution of sodium hydroxide. The vent stream is essential nitrogen, with a maximum concentration of 5.5 per cent w/w chlorine. The concentration of chlorine leaving the scrubber must be less than 50 ppm by weight. The maximum flow-rate of the vent stream to the scrubber will be 4500 kg/h. Design a suitable packed column for this duty. The column will operate at 1.1 bar and ambient temperature. If necessary, the aqueous stream may be recirculated to maintain a suitable wetting rate. 

A reaction between organic compounds is carried out in the liquid phase in a stirred-tank reactor in the presence of excess formaldehyde. The organic reactants are nonvolatile in comparison with the formaldehyde. The reactor is vented to atmosphere via an absorber to scrub any organic material carried from the reactor. The absorber is fed with freshwater and the water from the absorber rejected to effluent. The major contaminant in the aqueous waste from the absorber is formaldehyde. 

While the use of low-sulfur fuels is one mechanism to reduce sulfur dioxide emission, alternatively most approaches focus on scrubbing or ridding the emissions in smoke stacks of sulfur dioxide gas. A number of different types of scrubbers, i.e., sulfur dioxide removal systems, are available for industry. One system sprays the flue gas into a liquid solution of sodium hydroxide. The hydroxide combines with SO2 and O2 to form the corresponding sulfate which can be removed from the aqueous solution ... 

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