Kinetics, stripping

Kinetics of suspension PVC are identical to the kinetics of mass PVC, both increasing in rate with conversion (90). After polymerization to about 80—90% conversion, excess monomer is recovered, the slurry is steam-stripped in a column to a residual monomer level of about 0.0001% (10 ppm), excess water is centrifuged off, and the resin is dried with hot air. 

The secondary ion XH2 + resulting from the stripping of a proton from the incident ion XH + by a molecule XH has very little kinetic energy in... 

If stripping also occurs in reactions of X + ions with HD, then XH +, and XD + should be formed with half the cross-sections as in the reactions X + + H2 and X + + D2, respectively (at the same kinetic energy E of the... 

The internal energy, U, of an ion which is formed in a stripping reaction is equal to the sum of the relative kinetic energy (according to Equation 11) plus the heat of the reaction W if W does not appear as... 

When the product ion moved with a higher kinetic energy than predicted by the stripping model, the collision apparently was more elastic— i.e., less kinetic energy of the incident ion was used for internal excitation of the products. In an ideal elastic collision with H transfer the products carry no internal energy at all. If the secondary ion moves forward and the H atom moves backwards, conservation of momentum requires that the primary ion has a velocity ... 

Although the Lewis cell was introduced over 50 years ago, and has several drawbacks, it is still used widely to study liquid-liquid interfacial kinetics, due to its simplicity and the adaptable nature of the experimental setup. For example, it was used recently to study the hydrolysis kinetics of -butyl acetate in the presence of a phase transfer catalyst [21]. Modeling of the system involved solving mass balance equations for coupled mass transfer and reactions for all of the species involved. Further recent applications of modified Lewis cells have focused on stripping-extraction kinetics [22-24], uncatalyzed hydrolysis [25,26], and partitioning kinetics [27]. 

The hydrodynamics of the moving drop are difficult to calculate, particularly the flow characteristics within the droplet itself. However, this technique is still used widely, because it is a simple and straightforward method. It was recently applied to study the stripping-extraction kinetics of Mn(II) in an aqueous-kerosene system [50,51]. The effect of anionic surfactants on the kinetics of extraction of lactic acid from an aqueous phase by Alamine 336 in a toluene phase was also studied by this technique [52]. 

Of considerable interest is the use of small isolated electrodes, in the form of strips or disks embedded in the wall, to measure local mass-transfer rates or rate fluctuations. Mass-transfer to spot electrodes on a rotating disk is represented by Eqs. (lOg-i) of Table VII. Analytical solutions in this case have to take account of curved streamlines. Despic et al. (Dlld) have proposed twin spot electrodes as a tool for kinetic studies, similar to the ring-disk electrode applications of disk and ring-disk electrodes for kinetic studies are discussed in several monographs (A3b, P4b). In fully developed channel or pipe flow, mass transfer to such electrodes is given by the following equation based on the Leveque model ... 

The most widely used amine is monoethanolamine (MEA), which is considered as a benchmark solvent because of its high cyclic capacity, significant absorption-stripping kinetic rates at low C02 concentration and high solubility in water. Some other amine-based solvents such as diethanolamine (DEA), triethanolamine (TEA), diglycolamine (DGA), N-methyldiethanol-amine (MDEA), piperazine (PZ), 2-amino-2-methyl-l-propanol (AMP) and N-(2-aminoeth-yl)piperazine (AEP) have also traditionally been utilised. 

---