Liquid three-phase

So far only propene and butene are hydroformylated commercially using the RCH/RP process. A reason which has been postulated for this is the decreasing solubility in water with increasing number of C atoms in both the starting alkene and the reaction products (Figure 5.4) and the associated mass-transfer problems in the relatively complicated gas-liquid-liquid, three-phase reaction. 

K. Kawakami, K. Kawasaki, F. Shiraishi, and K. Kusunoki, Perfonnance in a Honeycomb Monolithic Bioreactor in a Gas-Solid-Liquid Three-Phase System, Ind. Eng. Chem. Res. 25 394 (1989). 

Yanagida, S., K. Takahashi, and M. Okahara, Solid-Solid-Liquid Three Phase Transfer Catalysis of Polymer Bound Acyclic Poly(oxyethylene) Derivatives Applications to Organic Synthesis, ... 

It is rather difficult to establish a reasonably accurate mathematical model of a gas-liquid-liquid three-phase reactor for biphasic hydroformylation, because of the complexity in formulating all the necessary mechanisms such as phase dispersion and distribution, multiphase flow, interphase mass transfer, micromixing, and the hydroformylation reaction. Besides, the task is further complicated by turbulence in multiphase flow and the complex domain of stirred-tank reactors. 

Yue, J., Rebrov E.V. and Schouten, J.C. (2014) Gas-liquid-liquid three-phase flow pattern and pressure drop in a microfluidic chip Similarities with gas-liquid/liquid-liquid flows. Lab Chip, 14, 1632-1649. 

Figure 2 Flow maps of T-junction microchannels. (A) Liquid/liquid two-phase flow in a T-junction microchannel, whose cross-section is 0.52 x 0.2 mm for the main channel and 0.27 x 0.2 mm in for the side channel. The solid dots are from the experiment with water/2 wt% spanSO-dodecane and the hollow dots are from the experiment with octane/3 wt% SDS (sodium dodecyl sulfonate)—water. (B and D) Gas/liquid two-phase and gas/liquid/liquid three-phase flows in a cross-junction microchannel. (C) Liquid/ liquid/liquid three-phase flows in a cross-junction microchannel in a flow-focusing microfluidic device. Panels (B and D) These figures are adapted from Wang et al (2013b) with permission of Wiley. Panel (C) Reprinted from Nieetal (2005) with permission of American Chemical Society.

Wang K, Lu YC, Qin K, et al Generating g3s-Hquid-liquid three-phase microflows in a cross-junction microchannel device, Chem Eng Technol 36 1047—1060, 2013b. 

A three-phase fluidized bed is shovm in Figure 6.12. In a fluidized bed, the finely crushed catalyst particles are fluidized because of the movement of the liquid. Three-phase fluidized beds usually operate in a concurrent mode with gas and liquid flowing upward. However,... 

Yanagida, S., and Takahashi, K., Losid-solid-liquid three phase transfer catalysis of polymer bound acyclic poly(oxyethylene) derivatives. Application to organic synthesis, J. Org. Chem., 44, 1099, 1979. 

The occurrence of sizable contact angle hysteresis on perfectly smooth surfaces was reported as early as 1952 by Bartell and Bjorklund [46] in a three-liquid, three-phase system comprising mercury, benzene, and water. A strong conclusion was not drawn that time presumably due to the observation of an unexplained, aging phenomenon on the three-liquid system. Four decades later, Chen and coworkers [47] reported a study of the contact angle hysteresis of several monolayer modified mica... 

When the fluids being treated contain water, the equilibria most often involve three phases (liquid-liquid-vapor). 

The strict definition of a phase is any homogeneous and physically distinct region that is separated from another such region by a distinct boundary . For example a glass of water with some ice in it contains one component (the water) exhibiting three phases liquid, solid, and gaseous (the water vapour). The most relevant phases in the oil industry are liquids (water and oil), gases (or vapours), and to a lesser extent, solids. 

The three general states of monolayers are illustrated in the pressure-area isotherm in Fig. IV-16. A low-pressure gas phase, G, condenses to a liquid phase termed the /i uid-expanded (LE or L ) phase by Adam [183] and Harkins [9]. One or more of several more dense, liquid-condensed phase (LC) exist at higher pressures and lower temperatures. A solid phase (S) exists at high pressures and densities. We briefly describe these phases and their characteristic features and transitions several useful articles provide a more detailed description [184-187]. 

Phenomena at Liquid Interfaces. The area of contact between two phases is called the interface three phases can have only aline of contact, and only a point of mutual contact is possible between four or more phases. Combinations of phases encountered in surfactant systems are L—G, L—L—G, L—S—G, L—S—S—G, L—L, L—L—L, L—S—S, L—L—S—S—G, L—S, L—L—S, and L—L—S—G, where G = gas, L = liquid, and S = solid. An example of an L—L—S—G system is an aqueous surfactant solution containing an emulsified oil, suspended soHd, and entrained air (see Emulsions Foams). This embodies several conditions common to practical surfactant systems. First, because the surface area of a phase iacreases as particle size decreases, the emulsion, suspension, and entrained gas each have large areas of contact with the surfactant solution. Next, because iaterfaces can only exist between two phases, analysis of phenomena ia the L—L—S—G system breaks down iato a series of analyses, ie, surfactant solution to the emulsion, soHd, and gas. It is also apparent that the surfactant must be stabilizing the system by preventing contact between the emulsified oil and dispersed soHd. FiaaHy, the dispersed phases are ia equiUbrium with each other through their common equiUbrium with the surfactant solution. 

A hst of 74 GLS reacdions with hterature references has been compiled by Shah Gas-Liquid-Solid Reactions, McGraw-HiU, 1979), classified into groups where the solid is a reactant, or a catalyst, or inert. A hst of 75 reactions made by Ramachandran and Chaudhari (Three-Phase Chemical Reactors, Gordon and Breach, 1983) identifies reactor types, catalysts, temperature, and pressure. They classify the processes according to hydrogenation of fatty oils, hydrodesulfurization, Fischer-Tropsch reactions, and miscellaneous hydrogenations and oxidations. 

Some contrasting characteristics of the main lands of three-phase reactors are summarized in Table 23-15. In trickle bed reactors both phases usually flow down, the liquid as a film over the packing. In flooded reactors, the gas and hquid flow upward through a fixed oed. Slurry reactors keep the solids in suspension mechanically the overflow may be a clear liquid or a slurry, and the gas disengages from the... 

Three-phase fluidized bed reactors are used for the treatment of heavy petroleum fractions at 350 to 600°C (662 to 1,112°F) and 200 atm (2,940 psi). A biological treatment process (Dorr-Oliver Hy-Flo) employs a vertical column filled with sand on which bacderial growth takes place while waste liquid and air are charged. A large interfacial area for reaction is provided, about 33 cmVcm (84 inVirr), so that an 85 to 90 percent BOD removal in 15 min is claimed compared with 6 to 8 h in conventional units. 

The teehniques of membrane extraetion permit an effieient and modern applieation of elassieal liquid-liquid extraetion (LLE) ehemistry to instmmental and automated operation. Various shorteomings of LLE are overeome by membrane extraetion teehniques as they use none or very little organie solvents, high enriehment faetors ean be obtained and there ai e no problems with emulsions. A three phase SLM system (aq/org/aq), where analytes are extraeted from the aqueous sample into an organie liquid, immobilized in a porous hydrophobie membrane support, and further to a seeond aqueous phase, is suitable for the extraetion of polar eompounds (aeidie or basie, ehai ged, metals, ete.) and it is eompatible with reversed phase HPLC. A two-phase system (aq/org) where analytes ai e extraeted into an organie solvent sepai ated from the aqueous sample by a hydrophobie porous membrane is more suitable for hydrophobie analytes and is eompatible with gas ehromatography. 

Phospholipids. For the removal of ionic contaminants from raw zwitterionic phospholipids, most lipids were purified twice by mixed-bed ionic exchange (Amberlite AB-2) of methanolic solutions. (About Ig of lipid in lOmL of MeOH). With both runs the first ImL of the eluate was discarded. The main fraction of the solution was evaporated at 40°C under dry N2 and recryst three times from n-pentane. The resulting white powder was dried for about 4h at 50° under reduced pressure and stored at 3°. Some samples were purified by mixed-bed ion exchange of aqueous suspensions of the crystal/liquid crystal phase. [Kaatze et al. J Phys Chem 89 2565 7955.]... 

Fig. 3.1. The phase diagram for the lead-tin alloy system. There ore three phases L - a liquid solution of lead and tin (Pb) - a solid solution of tin in lead and (Sn) - o solid solution of lead in tin. The diagram is divided up into six fields - three of them are single-phase, and three ore two-phose.

The other place where the constitution is not fully defined is where there is a horizontal line on the phase diagram. The lead-tin diagram has one line like this - it runs across the diagram at 183°C and connects (Sn) of 2.5 wt% lead, L of 38.1% lead and (Pb) of 81% lead. Just above 183°C an alloy of tin -i- 38.1% lead is single-phase liquid (Fig. 3.5). Just below 183°C it is two-phase, (Sn) -i- (Pb). At 183°C we have a three-phase mixture of L -I- (Sn) -I- (Pb) but we can t of course say from the phase diagram what the relative weights of the three phases are. 

The cloudiness of ordinary ice cubes is caused by thousands of tiny air bubbles. Air dissolves in water, and tap water at 10°C can - and usually does - contain 0.0030 wt% of air. In order to follow what this air does when we make an ice cube, we need to look at the phase diagram for the HjO-air system (Fig. 4.9). As we cool our liquid solution of water -i- air the first change takes place at about -0.002°C when the composition line hits the liquidus line. At this temperature ice crystals will begin to form and, as the temperature is lowered still further, they will grow. By the time we reach the eutectic three-phase horizontal at -0.0024°C we will have 20 wt% ice (called primary ice) in our two-phase mixture, leaving 80 wt% liquid (Fig. 4.9). This liquid will contain the maximum possible amount of dissolved air (0.0038 wt%). As latent heat of freezing is removed at -0.0024°C the three-phase eutectic reaction of... 

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