Breakthrough capacity

Mass Transfer and Useful Capacity. The term useful capacity, also referred to earlier as breakthrough capacity, differs from the equihbrium capacity shown on Figures 9a and 9b. The useful capacity is a measure of the total moisture taken up by a packed bed of adsorbent at the point where moisture begins to appear in the effluent. Thus the drying process cycle must be stopped before the adsorbent is fully saturated. The portion of the bed that is not saturated to an equihbrium level is called the mass-transfer 2one. 

C, can be obtained by measuring the breakthrough capacities of two beds and using the following equation ... 

Figure 5.12 Sorption breakthrough curves - effect of flow rate of breakthrough capacity (C0 = influent concentration C = effluent concentration).

Lead(II) adsorbed on both columns was quantitatively eluted with ca. 6 bed volumes of 1 M nitric acid. In this work, 2 cylcles of the adsorption-elution operation were repeated at each flow rate. Then 16 cycles of the adsorption and elution operation were conducted for each column. In the case of FPS-f column, averaged recovery was 104% with standard deviation (sd) of 4 % (n = 16) and for the other column, averaged recovery 103% with sd of 4 %. Table 3 summarizes numerical data for results shown in Fig. 4. Breakthrough capacities at C/Co = 0.05 are 0.54 - 0.57 and 0.28 - 0.33 mmol/g for FPS-f and FP columns, respectively. Total uptake was 0.78 -0.83 mmol/g for FPS-f and 0.51 - 0.54 mmol/g for RF-f. During repeated adsorption-elution operations, no deterioration of both RFP-f and FP-f was observed. 

As conclusion, bifunctional fibers having both phosphonic acid and sulfonic acid groups exhibit the characteristic metal ion selectivity and high breakthrough capacities in addition to the extremely fast adsorption rates. Studies on behavior of FPS-f in adsorption of other heavy metals like Fe(III) are now in progress. The bifunctional fiber developed in this work is attractive to application to the protection of the environment because of its extremely rapid adsorption rates and characteristic metal ion selectivity. 

The presented model is very convenient when we want to calculate the breakthrough capacity, i.e. the solid loading obtained until breakpoint. We have (Helfferich, 1995)... 

The maximum adsorption (or ion-exchange) and breakthrough capacity can be measured using the experimental breakthrough curve (C versus V ff) by integration (Perry and Green, 1999 Helfferich, 1962) ... 

The selections are presented in Table IV along with the breakthrough times, breakthrough volumes, breakthrough capacities, and desorption efficiencies under the specified sampling conditions. 

This presumably could show up in the breakthrough capacity of an operating molecular sieve bed. Breakthrough capacity is shown to increase from 4 to 6.7 g n-paraffin introduced from feed per 100 g of molecular sieves upon increasing the temperature from 548 to 604 K, followed by a decrease to 6.3 g/100 g upon further increasing the temperature to 634 K (10). 

Other parameters characterizing a PFAR are the column breakthrough capacity, Bc, the column saturation capacity, Sc, and the column efficiency, E, of the PFIEBR, which are calculated with the following equations [105] ... 

The dilution of the feed stream will allow for selective displacement of the cations, and therefore, increase the capacity of ion exchange columns. Loading the columns to near breakthrough capacity will displace the impurity cations so that the subsequent steps of processing will be more effective. 

FIGURE 4 Breakthrough curves for BSA on STREAMLINE DEAE. The breakthrough capacity is determined using frontal analysis. 

The results from the breakthrough experiments are collected in Table 1. As expected, the samples differ in HjS adsorption whereas the adsorption of SOj is comparable [12, 13]. Much higher HjS breakthrough capacity is obtained for SC-2 than for SC-1 (three fold difference). It is worth to mention that the obtained capacities are slightly smaller than those reported previously [12, 13]. This is likely the result of fertilizer oxidation during its exposure to air. After exhaustion in SOj breakthrough tests still some capacity for HjS exists and, especially on the SC-2 sample. 

Table 1. HjS and SO2 breakthrough capacities [mg/g/ imnol/g], total amount of sulfur adsorbed...

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