Pore volume displacement

FIGURE 9.1. Boron and Cl- concentrations in successive pore volume displacements (PVD) of the Traver loam soil. The solid vertical line at PVD = 40 indicates an intervening 30-day. saturated storage period. F. J. Peryea, F. T. Dingham and J. D. Rhoades. 1985. Soil Sci. Soc. Am. J. 49 840. 

Evaluation of pore volume by displacement of mercury and another fluid... 

Solubilizing activity are also used in enhanced oil recovery. Tar and extremely viscous hydrocarbons are recovered by the injection of an aqueous solution of an anionic orthophosphate ester surfactant into a petroleum formation, retaining the surfactant in the formation for about 24 h, and displacing the solubilized hydrocarbons toward a recovery well. The surfactant forms an oil microemulsion with the hydrocarbons in the formation. An anionic monoorthophosphate ester surfactant which is a free acid of an organic phosphate ester was dissolved in water. The input of surfactant solution was 2-25% of the pore volume of the formation [250]. To produce a concentrate for the manufacture... 

If the NMR response is capable of estimating the pore size distribution, then it also has the potential to estimate the fraction of the pore space that is capable of being occupied by the hydrocarbon and the remaining fraction that will only be occupied by water. The Free Fluid Index (FFI) is an estimate of the amount of potential hydrocarbons in the rock when saturated to a given capillary pressure. It is expressed as a fraction of the rock bulk volume. The Bulk Volume Irreducible (BVI) is the fraction of the rock bulk volume that will be occupied by water at the same capillary pressure. The fraction of the rock pore volume that will only be occupied by water is called the irreducible water saturation (Siwr = BVI/cj>). The amount of water that is irreducible is a function of the driving force to displace water, i.e., the capillary pressure. Usually the specified driving force is an air-water capillary pressure of 0.69 MPa (100 psi). 

Fig. 2.7. Flush configuration of a reaction model. Unreacted fluid enters the equilibrium system, which contains a unit volume of an aquifer and its pore fluid, displacing the reacted fluid.

Fig. 30.3. Variation in pH during simulated alkali floods of a clastic petroleum reservoir at 70 °C, using 0.5 N NaOH, Na2C03, and Na2Si03 solutions. Pore fluid is displaced by unreacted flooding solution at a rate of one-half of the system s pore volume per day.

Initially, the aquifer contains a dilute Ca-HC03 groundwater, including a negligible amount of Pb++ as well as an equal quantity of Br, which serves in the calculation as a non-reactive tracer. At the onset of the simulation, water containing 1 mmolal Pb++ and Br- passes into the aquifer until half its pore volume has been displaced. At this point, the composition of water entering the aquifer changes to that of the initial fluid, uncontaminated water nearly devoid of lead and bromide. The simulation continues until water in the aquifer has been replaced 30 times. 

When half the aquifer s pore volume has been displaced, the inlet fluid in the simulation changes to uncomtaminated water. At this point, the contamination has progressed across one-quarter of the aquifer, reflecting the retardation factor of two. 

Fig. 32.2. Remediation of the aquifer shown in Figure 32.1, as the simulation continues. After water contaminated with Pb++ displaces half of the aquifer s pore volume, clean water is flushed through the aquifer until a total of 30 pore volumes have been replaced. Flushing attenuates Pb++ concentration in the groundwater (top), so that it gradually approaches drinking water standards (MCL, or Maximum Contamination Level), and slowly displaces most of the sorbed metal from the Fe(OH)3 surface, primarily from the weak surface sites.

The reaction front reaches the end of the aquifer in the simulation after somewhat less than three pore volumes have been displaced. At this point, the contaminant begins to pass out of the domain. Remediation of the aquifer, however, proceeds slowly, as shown in Figure 32.2. Even after 30 pore volumes have been flushed, some lead remains sorbed to weak sites in the aquifer sediments, and the Pb++ concentration in the groundwater remains above the limits sets as drinking water... 

K( results predict that flushing only a few pore volumes of clean water through the aquifer can displace the contamination, suggesting pump-and-treat remediation will be quick and effective. Models constructed with the surface complexation model, in contrast, depict pump-and-treat as a considerably slower and less effective remedy. 

Nguyen et al. [205] designed a volume displacement technique that was used to measure the capillary pressures for both hydrophobic and hydrophilic materials. One requirement for this method is that the sample material must have enough pore volume to be able to measure the respective displaced volume. Basically, while the sample is filled wifh water and then drained, the volume of water displaced is recorded. In order for the water to be drained from fhe material, it is vital to keep the liquid pressure higher than the gas pressure (i.e., pressure difference is key). Once the sample is saturated, the liquid pressure can be reduced slightly in order for the water to drain. From these tests, plots of capillary pressure versus water saturation corresponding to both imbibitions and drainages can be determined. A similar method was presented by Koido, Furusawa, and Moriyama [206], except they studied only the liquid water imbibition with different diffusion layers. 

Sieve analysis using standard mesh screens is commonly used to determine particle size and size distribution of pellets and the reader is referred to standard texts for further information (61). Several types of densities have been defined for pellets based on interparticulate (void fraction) and intraparticulate pore volumes and include true, apparent, effective, bulk and tapped. The bulk and tapped densities may be obtained using simple devices, such as that used to evaluate granulations in tableting, while the true and apparent densities need more complex techniques based on mercury intrusion, gas flow, powder displacement, imaging or minimum fluidization velocity (62). 

Figure I Density modified displacement of chlorobenzene with 4 % Aerosol MA/OT + 25 % n-butanol (A) corresponds to initial injection of chlorobenzene, (B) and (C) correspond to increasing pore volumes of surfactant/alcohol flood ( (C) is a close-up of the outlet of the cell). Dyed chlorobenzene is outlined in figures above. Note that lines are also visible in B indicating the movement of dyed surfactant/alcohol solution.

Figure 10.6. Types of breakthrough curves for miscible displacement. C/C0 is the relative concentration of the chemical component measured in the effluent. Pore volume is the ratio of the volume of the effluent to the volume of solution in the column (from Nielsen and Biggar, 1962, with permission).

Zeolite-based processes have gradually displaced conventional ones, involving supported H3P04 or A1C13 as catalysts, in the manufacture of cumene, the raw material for phenol production [1, 6, 39]. A three-dimensional dealuminated mordenite (3-DDM) catalyst was developed by Dow Chemical for this purpose [39]. Dealumination, using a combination of acid and thermal treatments, increases the Si/Al ratio from 10-30 up to 100-1000 and, at the same time, changes the total pore volume and pore-size distribution of the mordenite. The... 

---