Sodium hydroxide wash

Higher ethyl chloride efficiency is claimed for a process utilising a hydrocarbon diluent coupled with stepwise addition of sodium hydroxide (80). Product work-up includes distillation to remove residual unreacted ethyl chloride, added diluent, methanol, and diethyl ether neutralization of excess sodium hydroxide washing in water to remove salts drying and grinding. 

Estrone methyl ether (100 g, 0.35 mole) is mixed with 100 ml of absolute ethanol, 100 ml of benzene and 200 ml of triethyl orthoformate. Concentrated sulfuric acid (1.55 ml) is added and the mixture is stirred at room temperature for 2 hr. The mixture is then made alkaline by the addition of excess tetra-methylguanidine (ca. 4 ml) and the organic solvents are removed. The residue is dissolved in heptane and the solution is filtered through Celite to prevent emulsions in the following extraction. The solution is then washed threetimes with 500 ml of 10 % sodium hydroxide solution in methanol to remove excess triethyl orthoformate, which would interfere with the Birch reduction solvent system. The heptane solution is dried over sodium sulfate and the solvent is removed. The residue is satisfactory for the Birch reduction step. Infrared analysis shows that the material contains 1.3-1.5% of estrone methyl ether. The pure ketal may be obtained by crystallization from anhydrous ethanol, mp 99-100°. Acidification of the methanolic sodium hydroxide washes affords 10-12 g of recovered estrone methyl ether. 

Amorphous cellulose, so defined, was reported for two simple but noteworthy modifications of cotton linters. First, linters which had been swollen with cold 10% sodium hydroxide, washed, and dried by solvent exchange prior to thallation and methylation, showed an amorphous content as high as 27 %. Secondly, unswollen linters appeared to contain only 0.25 to 0.50% of amorphous cellulose. Similarly, swollen ramie appeared to contain 18% of amorphous cellulose unswollen ramie, 0.25%. 

Although solvent samples have been observed for approximately one year without any solids formation, work was completed to define a new solvent composition that was thermodynamically stable with respect to solids formation and to expand the operating temperature with respect to third-phase formation.109 Chemical and physical data as a function of solvent component concentrations were collected. The data included BC6 solubility cesium distribution ratio under extraction, scrub, and strip conditions flowsheet robustness temperature range of third-phase formation dispersion numbers for the solvent against waste simulant, scrub and strip acids, and sodium hydroxide wash solutions solvent density viscosity and surface and interfacial tension. These data were mapped against a set of predefined performance criteria. The composition of 0.007 M BC6, 0.75 M l-(2,2,3,3-tetrafluoropropoxy)-3-(4-.sw-butylphenoxy)-2-propanol, and 0.003 M TOA in the diluent Isopar L provided the best match between the measured properties and the performance criteria. 

Wear eye protection and gloves. To each 1 g of aldicarb, add 100 mL of 3 M sulfuric acid (17 mL of concentrated sulfuric acid added to 83 mL of cold water) and 4.7 g of potassium permanganate. The mixture is stirred at room temperature for 30 minutes. Add a saturated solution of sodium bisulfite until the solution is colorless. The solution is neutralized by the careful addition of soda ash (foaming may occur) or 5% aqueous sodium hydroxide. Wash the clear solution into the drain with water.4... 

In a 250 ml three-necked flask was placed (dichloroiodo)benzene (7.25 g, 30 mmol) with light protection, under nitrogen. Then 2,3-dimethylbutane (30.25 g, 350 mmol) and trihexylborane (400 mg, 1.5 mmol) were introduced by syringes through a septum inlet. The mixture was stirred at room temperature for about 2 h during the reaction hydrogen chloride evolved was carried into an aqueous sodium hydroxide solution by a weak stream of nitrogen. The reaction mixture was neutralized with dilute sodium hydroxide, washed with water several times and dried. Fractional distillation afforded 2-chloro-2,3-dimethylbutane (3.22 g, 89%), b.p. 109-110°C. 

The best wash procedure is no wash procedure, but this implies that the migration times are stable. If migration times increase with each ensuing run, add a 1-2-min 0.1 N sodium hydroxide wash. If the trend shows a decrease, add a 1-2-min acid wash. While 0.1 N phosphoric acid is often used, be careful if phosphate buffer is not used for the separation. Wall effects can occur if phosphate binds to both the wall and the solute. If protein or other cations are stick-... 

Put the combined dichloromethane solution in a separating funnel (500 mL) and wash successively with 2 M sodium hydroxide solution (3 x 100 mL) and then water (2 x 100 mL). The sodium hydroxide washes must be put in the hypochlorite bucket. 

Soapstock is the byproduct of caustic (dilute sodium hydroxide) washing of crude oil during refining. Free fatty acids, hydrolyzed phospholipids, and unsaponifiable matter are included in the soapstock. Free fatty acids are the most valuable compo-... 

Cleaning Up The pot residue from the reaction is combined with the sodium hydroxide wash and neutralized with sodium Ccu-bonate. The pot residue from the distillation of the product is combined with the acetone used to wash out the apparatus and placed in the organic solvents container. If the sodium sulfate is dry, it can be placed in the nonhazardous solid waste container. If it is wet with organic solvents, it must be placed in the hazardous solid waste container for solvent-contaminated drying agent. 

FIGURE 7.4 Cross section through the drum and slurry trough of a drum filter, used for the continuous separation of a solid from a liquid suspension. This version includes a water wash for scavenging the last traces of a solution of value. Sodium hydroxide washings are retained in the process by collecting them separately in the filter and using this to dissolve fresh sodium carbonate, and to slake burned lime. (Modified from Codd et al. with permission [35]). 

Commercial sodium hydroxide Wash with clean, cold running water... 

Carefully dilute the stillpot residue from the reaction with water and then slowly combine this with the water and the sodium hydroxide washes. Neutralize the combined aqueous mixture with sodium carbonate and flush the solution down the drain with water. The sodium sulfate used as the drying agent is contaminated with product, so place it in the container for halogenated solids. Place the residue in the stillpot from the distillation in the Miniscale Procedure into the container for halogenated liquids. Dilute the silver nitrate test solution with water and flush it down the drain unless instructed otherwise. Place the sodium iodide/acetone test solution in the container for halogenated liquids. 

Membranes were cleaned according to the following procedure i) water rinsing ii) sodium hydroxide washing iii) water rinsing. Sodium hydroxide had a concentration of 0.4% for Pall and Polymem membranes and 0.5% for Amicon membranes. 

Assayed by base extraction of about 0-4 g with ether from sodium chloride solution after addition of excess of sodium hydroxide, washing the combined ether extracts adding excess 0-lN hydrochloric acid, removing ether and back-titrating with 0-lN sodium hydroxide to methyl red. 1 ml 0-1N = 0 02123 g anhydrous. 

---