Phenol removal with ammonia

The rate of stripping or the stripabiUty on cataly2ed urethane and epoxy resin finishes can be increased by adding formic acid, acetic acid, and phenol. Sodium hydroxide, potassium hydroxide, and trisodium phosphate [10101-89-0] may be added to the formula to increase the stripabiUty on enamel and latex paints. Other activators include oleic acid [112-80-17, trichloroacetic acid [76-85-9], ammonia, triethanolamine [102-71-6], and monoethyl amine. Methylene chloride-type removers are unique in their abiUty to accept cosolvents and activators that allow the solution to be neutral, alkaline, or acidic. This abihty gready expands the number of coatings that can be removed with methylene chloride removers. 

Type 1. In this case the mass transfer rate through the membrane phase is increased by incorporating a stripping agent in the internal phase which reacts with the solute yielding a membrane insoluble product. Examples of this system are extraction of weak acids or bases from wastewater such as phenol removal by NaOH solution as the internal phase [3-8] and removal of ammonia by H2SO4 solution as the internal phase [9-10]. 

Acid or base can be used as an internal phase or stripping phase for ELM process depending upon solute to be extracted, for example, Cahn and Li [3] used NaOH solution as the internal phase for phenol removal from wastewater. H2SO4 solution was used as the internal phase for removal of ammonia [4-8]. The solute extraction rate also increases with an increase in the amount of internal reagent present in the emulsion. 

Typically, reaction is carried out batch-wise in a stirred reactor, jacketed for heating and cooling. The reactor is also fitted with a condenser such that either reflux or distillation may take place, as required. A mixture of phenol, formalin and ammonia (about 1-3% on the weight of phenol) is heated under reflux at about 100°C for 0.25-1 hour and then water is removed by distillation under reduced pressure (to limit further reaction). Distillation is continued until a cooled sample of the residual resin has a melting point in the range 45—50°C. The resin is then quickly discharged and cooled to give a hard, brittle solid. In an alternative procedure, the removal of water is not taken to completion but is halted when the resol content of the residual aqueous solution reaches about 70%. The solution is then used directly, mainly in the preparation of paper laminates. In the preparation of such aqueous solutions, the preferred catalyst is... 

Another class of thermosetting resins used as adhesives involves the polymerization of formaldehyde with urea or phenols. These materials are very cheap and find extensive use in binding wood, e.g., plywood, chipboard, and particle board. Foamed urea-formaldehyde has also been used as insulation (UFFl) in homes because of its ability to be injected into the walls of older homes. Unfortunately, the foam is not very stable and shrinks and hydrolyzes to liberate formaldehyde and possibly other toxic vapors. Recent work has, however, shown that the addition (and subsequent removal) of ammonia (NH3) to the foam can reduce the level of formaldehyde released by the polymer. This release of formaldehyde also occurs in plywood and particle board, and these materials must be sealed to avoid the formation of toxic levels (TLV = 0.10 ppm or 120 pg/m ) of formaldehyde. 

Consider an oily membrane without any acidic cation exchanger (see Problem 5.2.8). Through such a membrane, which may be a liquid or a polymeric membrane, it is possible to remove ammonia NH3 (1 = 1), but not the ammonium ion NHj (i = 2). In a process somewhat analogous to that described for phenol removal in Sections 5.4.3 and 5.4.4, the feed solution is basic (pH > 10) small amounts of ammonia in the feed Q =f) permeate through the membrane to the other side (j = p), where there is a highly acidic solution to react with the ammonia. 

Carbon dioxide is not considoed to be a noxious impurity in die water nevertheless, it is completely removed with the ammonia and hydrogen sulfide during the stripping operatioiL The presence of phenol in the sour water may require the inclusion of a separate (dienol extraction step in the water treatment process, while the presoice of strong or nonvolatile acids can usually be handled in the sour aSer stripping system by the addifitm of caustic... 

Colorations or coloured precipitates are frequently given by the reaction of ferric chloride solution with.(i) solutions of neutral salts of acids, (ii) phenols and many of their derivatives, (iii) a few amines. If a free acid is under investigation it must first be neutralised as follows Place about 01 g. of the acid in a boiling-tube and add a slight excess of ammonia solution, i,e., until the solution is just alkaline to litmus-paper. Add a piece of unglazed porcelain and boil until the odour of ammonia is completely removed, and then cool. To the solution so obtained add a few drops of the "neutralised ferric chloride solution. Perform this test with the following acids and note the result ... 

C) Phenacyl and p-Bromophenacyl esters. Ammonium salts in aqueous-ethanolic solution do not however usually condense satisfactorily with phenacyl and />-bromophenacyl bromide. The aqueous solution of the ammonium salt should therefore be boiled with a slight excess of sodium hydroxide to remove ammonia, and the solution then cooled, treated with hydrochloric acid until just alkaline to phenol-phthalein, and then evaporated to dryness. The sodium salt is then treated as described (p. 349) to give the ester. Filter the ester, and wash with water to remove senium halide before recrystallisation. 

The ammonolysis of phenol (61—65) is a commercial process in Japan. Aristech Chemical Corporation (formerly USS Chemical Division of USX Corporation) currently operates a plant at Ha verb ill, Ohio to convert phenol to aniline. The plant s design is based on Halcon s process (66). In this process, phenol is vapori2ed, mixed with fresh and recycled ammonia, and fed to a reactor that contains a proprietary Lewis acid catalyst. The gas leaving the reactor is fed to a distillation column to recover ammonia overhead for recycle. Aniline, water, phenol, and a small quantity of by-product dipbenylamines are recovered from the bottom of the column and sent to the drying column, where water is removed. 

Potassium carbonate. Solid potassium hydroxide is very rapid and efficient. Its use is limited almost entirely to the initial drying of organic bases. Alternatively, sometimes the base is shaken first with a concentrated solution of potassium hydroxide to remove most of the water present. Unsuitable for acids, aldehydes, ketones, phenols, thiols, amides and esters. Also used for drying gaseous amines and ammonia. 

Carefully scrape the separated bromophenol blue spots on to a sheet of clean smooth-surfaced paper using a narrow spatula (this is easier if two grooves are made down to the glass on either side of the spots). Pour the blue powder into a small centrifuge tube, add 2 mL of ethanol, 5 drops of 0.880 ammonia solution, and stir briskly until the dye is completely extracted. Centrifuge and remove the supernatant blue solution from the residual white powder. Repeat this procedure with the separated Congo red and phenol red spots . 

Ammonia stripping also removes cyanide, phenols, and other VOCs typically found in cokemaking wastewater. Phenols may also be removed by conversion into nonodorous compounds or into crude phenol or sodium phenolate by either biological means (phenol concentration <25 mg/L) or by physical processes.21 However, the Koppers dephenolization process is considered to be quite effective as it lowers the phenol content by 80 to 90% in ammonia still wastes. In this process a stream stripping process followed by mixing in a solution of caustic soda results in renewal of pure phenol with the flue gas.8... 

A problem encountered with the use of the phenolic oximes in Ni recovery from ammoniacal solution is the co-extraction of ammonia that must be removed prior to generating the electrolyte for... 

Gasifiers typically produce contaminants that need to be removed before entering the fuel cell anode. These contaminants include H2S, COS, NH3, HCN, particulate, and tars, oils, and phenols. The contaminant levels are dependent upon both the fuel composition and the gasifier employed. There are two families of cleanup that can be utilized to remove the sulfur impurities hot and cold gas cleanup systems. The cold gas cleanup technology is commercial, has been proven over many years, and provides the system designer with several choices. The hot gas cleanup technology is still developmental and would likely need to be joined with low-temperature cleanup systems to remove the non-sulfur impurities in a fuel cell system. For example, tars, oils, phenols, and ammonia could all be removed in a low-temperature water quench followed by gas reheat. 

Sour water strippers are designed primarily for the removal of sulfides and can be expected to achieve 85-99% removal. If acid is not required to enhance sulfide stripping, ammonia will also be stripped, the percentage varying widely with stripping pH and temperature. Depending on pH, temperature, and contaminant partial pressure, phenols and cyanides can also be stripped with removal as high as 30%. 

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