Reaction-extraction

Transfer 30 g. of the hydrochloride to a 500 ml. separatory funnel, add 100 ml. of water and shake until a thin paste of uniform consistency is obtained add 10 per cent, aqueous sodium hydroxide solution in the cold with shaking until the whole mass has become bright green (the colour of the free base) and the mixture has an alkaUne reaction. Extract the free base by shaking with two 60 ml. portions of benzene (1). Dry the combined benzene extracts with a Uttle anhydrous potassium carbonate, and filter into a distiUing flask fitted with a water condenser. Distil off about half of the benzene, and pour the residual hot benzene solution into a beaker. Upon cooUng, the p-nitrosodimethylaniUne erystallises in deep green leaflets. Filter these off and dry them in the air. The yield of p-nitrosodimethylaniUne, m.p. 85°, from the hydrochloride is almost quantitative. 

The integral values of effective interfacial area can thus be obtained by measuring the reaction (extraction) rate and using physico-chemical properties of the reactants. A reaction satisfying the above conditions consists of hydrolysis of hexyl formate (11) ... 

Normal butenes and isobutylene are separated by a selective reaction-extraction... 

The process for the production of the pseudo-ionone referred to in the first claim, consisting in the subjection of a mixture of citral and acetone to the action of an alkaline agent, and in purifying the product of this reaction, extracted by means of ether, by fractional distillation, substantially as described. 

C/ 5bar after reaction extraction with SCCO2... 

OS 94][R 13][P 74]ForadmixtureofsampleswifhvaryingconcentrationsofCo(ll) and Cu(II), the respective changes in the Co(ll) chelate complex concentration as a function of contact time were optically derived [28]. Analysis was performed in the reaction/extraction area and also in the decomposition/removal area (Figure 4.102). As expected, more complex is formed in the reaction/extraction area with increasing contact time. Also, more complex results when increasing the Co(ll) concentration at constant Cu(ll) concentration. This proves that mass transfer is efficient (as high concentrations can also be handled) and that no interference from other analytes falsifies the measurement. As a result, calibration curves were derived. 

Figure 4.102 Dynamic evolution of Co chelate formation in the reaction/extraction and decomposition/removal areas at various concentrations ...

The superiority of extractive hydrolysis over acid hydrolysis with respect to its productivity, yield, raw materials, and waste streams, for the transformation of drug intermediates (e.g. for Primaxin) in formate ester form to the corresponding alcohol, has been effectively demonstrated by King et al. (1985). They carried out the hydrolysis of the relevant formate ester with simultaneous extraction of the desired product from the undesired impurities by two-phase reaction/extraction with a base. 

Uses Solvent for oils, waxes, perfumes, alkaloids, fats, and gums organic synthesis (Grignard and Wurtz reactions) extractant manufacture of gun powder, ethylene, and other organic compounds analytical chemistry perfumery alcohol denaturant primer for gasoline engines anesthetic. 

The overall extraction reaction (extraction stoichiometry) is represented by the eqnation ... 

In our first experiments, we had to find the size gf collagen peptide most amenable to the Quadrol program. The upper limit of the size of a peptide is determined by the amount of peptide that can be introduced into the spinning cup. Thickness of the film resulting from application of more than 10 mg of protein will interfere with the procedures of dissolving, reaction, extraction, and drying. However, the degradation should be started with approximately 300 nM of protein in order that the reaction can be extended to 40—60 identifiable residues. 

When the absorption of the hydrogen stops (how can this be determined ), cool the apparatus to room temperature in a hydrogen atmosphere. Write the equation of the reaction. Extract the boat from the tube. What is the colour of the product See how lithium hydride reacts with water. What is the nature of the bond in a lithium hydride molecule ... 

In all reactions, wood of white fir Abies concolor) has been used. For the alkaline nitrobenzene reactions, extractive-free —20+40 mesh heart-wood sawdust containing 28.0% Klason lignin was used. Sequential extraction of the original sawdust with alcohol-benzene, 95% ethanol, and hot water gave extractives amounting to 4.9, 0.5, and 1.2%, respectively. In the other oxidation reactions, nominal 5 -in. wood chips, commonly used in pulping procedures, were employed. The mixed sap wood-heart-wood chips contained 26.5% Klason lignin and sequential extractives of 3.3, 0.5, and 3.2%, respectively. 

Materials Reaction Extraction Evap°- Filtration Drying... 

Berg, B. E. Hansen, E. M. Gjorven, S. Greibrokk, T. On-Line Enzymatic Reaction, Extraction, and Chromatography of Fatty Acids and Triglycerides... 

Studies of the dubnium behavior. 930 experiments were conducted with 262Db produced at the Berkeley 88-Inch Cyclotron in the 249Bk(lsO,5n) reaction. Extractions were performed in the Aliquat336/Cl - HC1 system with a 50 s cyclic collection time of the KC1 aerosol on a Kel-F slider in ARCA II. The reaction products were fed onto the column in 10 M HC1 followed by the elution of a Ta fraction in 6 M HC1 and a Nb,Pa fraction in 6 M HNO3/O.OI5 M HF. The effluents were continuously sprayed through a 60 pm nozzle onto hot Ta discs on which they were evaporated to dryness by hot He gas and infrared light. Start of measurement of the activities was 60 s (Ta fraction) and 76 s (Nb, Pa fraction) after the end of collection, respectively. 

Combustion of char and gas occurs within the jet to provide the heat necessary for the endothermic devolatilization, gasification, and desulfurization chemical reactions. Extraction steam from the steam turbine is also fed to the gasifier. CO and H2 are the... 

The advantages of this approach compared with conventional methods are simplicity and omission of troublesome operations. The acid and alkali solutions cannot be used simultaneously in the conventional washing method, but this becomes possible by using three-phase flow in the microchannel. This chemical processing corresponds to the integration of eight MUOs on a microchip, two-phase formation, mixing and reaction, extraction, phase separation, three-phase... 

Dodecylbenzenesulfonyl chlorides have been prepared from the corresponding acids using chlorosulfonic acid,4 phosphorus oxychloride,2 and thionyl chloride.5 The use of catalytic amounts of DMF in conjunction with thionyl chloride is based on the work of H. Bosshard, et al. The insolubility of the DMF/thionyl chloride complex in the reaction solvent permits easy removal at the end of reaction. Extraction with dilute base removes the last trace of acids and the solution is pure enough for the next step. 

Extractive Reaction Extractive reaction combines reaction and separation in the same unit operation for the purpose of facilitating a desired reaction. To avoid confusion, the term extractive reaction is recommended for this type of process, while the term reaction-enhanced extraction is recommended for a process involving formation of reversible solute-extractant interactions and enhanced partition ratios for the purpose of facilitating a desired separation. The term reactive extraction is a more general term commonly used for both types of processes. 

An example of a sequential-reaction extractive reaction is the manufacture of 2,4-dinitrotoluene, an important precursor to 2,4-diaminotoluene and toluene diisocyanate (TDl) polyurethanes. The reaction involves nitration of toluene by using concentrated nitric and sulfuric acids which form a separate phase. Toluene transfers into the acid phase where it reacts with nitronium ion, and the reaction product transfers back into the organic phase. Careful control of liquid-liquid contacting conditions is required to obtain high yield of the desired product and minimize formation of unwanted reaction products. A similar reaction involves nitration of benzene to mononitrobenzene, a precursor to aniline used in the manufacture of many products including methylenediphenylisocyanate (MDI) for polyurethanes [Quadros, Reis, and Baptista, Ind. Eng. Chem. Res., 44(26), pp. 9414-9421 (2005)]. 

Reaction-extraction This technique involves chemical modification of solutes in solution in order to more easily extract them in a subsequent extraction operation. Applications generally involve modification of impurity compounds to facilitate purification of a desired product. An example is the oxygenation of sulfur-containing aromatic impurities present in fuel oil by using H2O2 and acetic acid, followed by hquid-liquid extraction into an aqueous acetonitrile solution [Shiraishi and Hirai, Energy and Fuels, 18(1), pp. 37-40 (2004) and Shiraishi et al., Ind. Eng. Chem. Res., 41, pp. 4362-4375 (2002)]. Another example involves esterification of aromatic alcohol impurities to facihtate their separation from apolar hydrocarbons by using an aqueous extractant solution [Kuzmanovid et al., Ind. Eng. Chem. Res., 43(23), pp. 7572-7580 (2004)]. 

Both water-free zirconium sulikte catafysts did not exhibit a significant activity Lewis acid sites are therefore not active in these suUated zirconia catalysts. Upon exposme to water vapor the initially water-free catalysts were active. The stability of the conventional sul ted zirconia catalysts appeared to be determined in the gas-phase by the volatilization of sulfuric acid. As a result, a highly porous catalyst was more effective than a catalyst based on zirconia of a relatively low porosity. With liquid-phase reactions extraction of sulfuric acid proceeds leading to an acid liquid, which is catalytically active also after separation of the solid catalyst from the reaction mixture. 

Exchange complex ] Phosphate + HCOg Chemical reaction Extraction... 

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