Entrained organic acid

After the reactor, the SO3 exhausted gas is separated from the organic acid. The exhaust gas, containing small amounts of non-converted SO2, unreacted SO3 and some entrained organic acid, has to be cleaned before emission to ambient atmosphere. The organic aerosol and fine SO3/H2SO4 droplets are separated fi om the exhaust gas flow in an electrostatic precipitator (ESP) and the gaseous SO2 and traces of SO3 gas are washed from the process air in a scrubber by dilute caustic solution, thus producing a mixed sulphite/sulphate solution. 

Unconverted SO2, unreacted SO3 (partly as sulphuric acid mist) and entrained organic acid mist droplets are present in the exhaust gas and are the main potential atmospheric pollutants. The sulphur dioxide is due mainly to the incomplete conversion of SO2 to SO3. A small proportion of SO2 may arise from the sulphonation reaction itself but generally the amount of SO2 in the waste gas is a direct function of SO2 converter efficiency. 

The ablated vapors constitute an aerosol that can be examined using a secondary ionization source. Thus, passing the aerosol into a plasma torch provides an excellent means of ionization, and by such methods isotope patterns or ratios are readily measurable from otherwise intractable materials such as bone or ceramics. If the sample examined is dissolved as a solid solution in a matrix, the rapid expansion of the matrix, often an organic acid, covolatilizes the entrained sample. Proton transfer from the matrix occurs to give protonated molecular ions of the sample. Normally thermally unstable, polar biomolecules such as proteins give good yields of protonated ions. This is the basis of matrix-assisted laser desorption ionization (MALDI). 

Although CO2 is the most commonly used supercritical fluid for extraction, the solubility of certain solutes in CO2 is usually low and causes an inconvenience. The remedy for this problem is to add some entrainers such as water to facilitate the extraction. In this background, the MD simulations were carried out to study the supercritical extraction of nicotine by CO2 in the presence and absence of water as entrainer[40]. In the tobacco leaf, nicotine molecule is bonded to other organic molecules and forms organic acid salts. The malic salts of nicotine was chosen as the model with nicotine bonded to two malic molecules by hydrogen bonds[41]. It is assumed that when malic salts of nicotine are extracted from tobacco leaf, supercritical CO2 or entrainer molecule attacks the hydrogen bonds and decomposes the salt into three molecules. 

Alkaline flooding is based on the reaction that occurs between the alkaline water and the organic acids, naturally occurring in some crudes, to produce in-situ surfactants or emulsifying soaps at the oil/water interface. Recent literature (i-J.) summarizes several proposed mechanisms by which alkaline water-flooding will enhance oil recovery. These mechanisms include emulsification and entrapment, emulsification and entrainment, and wettability reversal (oil-wet to water-wet or water-wet to oil-wet). Depending on the initial reservoir and experimental conditions with respect to oil, rock and injection water properties, one or more of these proposed mechanisms may be controlling. 

In the alkaline flood process, the surfactant is generated by the in situ chemical reaction between the alkali of the aqueous phase and the organic acids of the oil phase The surface-active reaction products can adsorb onto the rock surface to alter the wettability of the reservoir rock and/or can adsorb onto the oil-water interface to lower the interfacial tension. At these lowered tensions (1-10 dyne/cm), surface or shear-driven forces promote the formation of stable oil-in-water emulsions or unstable water-in-oil emulsions the nature of the emulsion phase depends on the pH, temperature, and electrolyte type and concentration. These different paths of the surface-active reaction products have created different recovery mechanisms of alkaline flooding. The four alkaline recovery mechanisms which have been cited in the recent literature are (i) Emulsification and Entrainment, (ii) Emulsification and Entrapment, (iii) Wettability Reversal from Oil-to Water-Wet, and (iv) Wettability Reversal from Water- to Oil-Wet. These four mechanisms are similar in that alkaline flooding enhances the recovery of acidic oil by two-stage processes. 

Alkaline Floods. Alkaline floods, typically using sodium hydroxide, generate surface active products by an in-situ chemical reaction between the injected alkali and the organic acids of the crude. Four possible mechanisms [95] are responsible for the recovery of oil by alkaline floods (1) emulsification and entrainment, (2) emulsification and entrapment, (3) wettability reversal from oil-wet to water-wet, and (4) wettability reversal from water-wet to oil-wet. One example in the literature of wettability alteration by alkali [96] was reported for an offshore field in the Gulf of Mexico fhat had a low recovery factor from primary production. The wettability of this reservoir was found, using the... 

The total batch time and the recoveries of the three products are pretty much the same with the wide 10°C mismatches of temperature upward or downward (101.73 or 81.73°C). Only when this setpoint is set to be too low at 71.73°C does the batch operation fail with the organic phase totally refluxed but still not able to reach the temperature setpoint. At this low temperature setpoint value causing total refluxing of the organic phase, Strategy A discussed in Section 13.3.2 should be implemented with two sequential steps in the batch sequence (aqueous product recovery step and followed by the entrainer-acetic acid recovery step). However, because our proposed procedure only allows for simultaneous recovery of the three products, the batch operation failed. 

Few data exist on the types and concentrations of dissolved organic species other than the mono- and dicarboxylic acids. However, some data suggest that dissolved organic acids do not account for all of the dissolved organic carbon in formation waters (Kharaka et al. 1986 Fisher 1987). These data must be interpreted with some caution, however, because a generally unknown fraction of the measured organic carbon could be due to entrained oil or dissolved hydrocarbons. 

Hydrogen Chloride as By-Product from Chemical Processes. Over 90% of the hydrogen chloride produced in the United States is a by-product from various chemical processes. The cmde HCl generated in these processes is generally contaminated with impurities such as unreacted chlorine, organics, chlorinated organics, and entrained catalyst particles. A wide variety of techniques are employed to treat these HCl streams to obtain either anhydrous HCl or hydrochloric acid. Some of the processes in which HCl is produced as a by-product are the manufacture of chlorofluorohydrocarbons, manufacture of aUphatic and aromatic hydrocarbons, production of high surface area siUca (qv), and the manufacture of phosphoric acid [7664-38-2] and esters of phosphoric acid (see Phosphoric acid and phosphates). 

After the SO converter has stabilized, the 6—7% SO gas stream can be further diluted with dry air, I, to provide the SO reaction gas at a prescribed concentration, ca 4 vol % for LAB sulfonation and ca 2.5% for alcohol ethoxylate sulfation. The molten sulfur is accurately measured and controlled by mass flow meters. The organic feedstock is also accurately controlled by mass flow meters and a variable speed-driven gear pump. The high velocity SO reaction gas and organic feedstock are introduced into the top of the sulfonation reactor,, in cocurrent downward flow where the reaction product and gas are separated in a cyclone separator, K, then pumped to a cooler, L, and circulated back into a quench cooling reservoir at the base of the reactor, unique to Chemithon concentric reactor systems. The gas stream from the cyclone separator, M, is sent to an electrostatic precipitator (ESP), N, which removes entrained acidic organics, and then sent to the packed tower, H, where SO2 and any SO traces are adsorbed in a dilute NaOH solution and finally vented, O. Even a 99% conversion of SO2 to SO contributes ca 500 ppm SO2 to the effluent gas. 

Cosolvents ana Surfactants Many nonvolatile polar substances cannot be dissolved at moderate temperatures in nonpolar fluids such as CO9. Cosolvents (also called entrainers, modifiers, moderators) such as alcohols and acetone have been added to fluids to raise the solvent strength. The addition of only 2 mol % of the complexing agent tri-/i-butyl phosphate (TBP) to CO9 increases the solubility ofnydro-quinone by a factor of 250 due to Lewis acid-base interactions. Veiy recently, surfac tants have been used to form reverse micelles, microemulsions, and polymeric latexes in SCFs including CO9. These organized molecular assemblies can dissolve hydrophilic solutes and ionic species such as amino acids and even proteins. Examples of surfactant tails which interact favorably with CO9 include fluoroethers, fluoroacrylates, fluoroalkanes, propylene oxides, and siloxanes. 

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