Mass recovery

Kutrieb Corporation (Chetek, Wisconsin) operates a pyrolator process for converting tires into oil, pyrolytic filler, gas, and steel. Nu-Tech (Bensenvike, Illinois) employs the Pyro-Matic resource recovery system for tire pyrolysis, which consists of a shredding operation, storage hopper, char-coUection chambers, furnace box with a 61-cm reactor chamber, material-feed conveyor, control-feed inlet, and oil collection system. It is rated to produce 272.5 L oil and 363 kg carbon black from 907 kg of shredded tires. TecSon Corporation (Janesville, Wisconsin) has a Pyro-Mass recovery system that pyroly2es chopped tire particles into char, oil, and gas. The system can process up to 1000 kg/h and produce 1.25 MW/h (16). 

The [nimary objective of the VOC-condensation system is to meet mass-recovery objectives. However, heat is a key element in realizing the mass objectives. Hence, the mass and heat interactions of the problem have to be identified and reconciled. This can be achieved by converting the VOC-recovery task from a mass-transfer problem to a heat-transfer duty. This can be accomplished by relating the... 

The ionic species of the mobile phase will also affect the separation. This is shown in Table 4.3 by the difference in resolution values for magnesium chloride buffer compared to sodium sulfate buffer. In addition, calibration curves for proteins in potassium phosphate buffers are shallower than those generated in sodium phosphate buffers. The slope of the curve in Sorenson buffer (containing both Na and ) is midway between the slopes generated with either cation alone (1). Table 4.4 illustrates the impact of different buffer conditions on mass recovery for six sample proteins. In this case, the mass recovery of proteins (1,4) is higher with sodium or potassium phosphate buffers (pH 6.9) than with Tris-HCl buffers (pH 7.8). 

TABLE 4.4 Effect of Buffer Composition on Mass Recovery of Proteins from TSK-GEL G3000SW< ... 

TABLE 4.5 Mass Recovery as a Function of Protein Sampie Load ... 

Vitamin B12 catalyzed also the dechlorination of tetrachloroethene (PCE) to tri-chloroethene (TCE) and 1,2-dichloroethene (DCE) in the presence of dithiothreitol or Ti(III) citrate [137-141], but zero-valent metals have also been used as bulk electron donors [142, 143]. With vitamin B12, carbon mass recoveries were 81-84% for PCE reduction and 89% for TCE reduction cis-l,2-DCE, ethene, and ethyne were the main products [138, 139]. Using Ni(II) humic acid complexes, TCE reduction was more rapid, leading to ethane and ethene as the primary products [144, 145]. Angst, Schwarzenbach and colleagues [140, 141] have shown that the corrinoid-catalyzed dechlorinations of the DCE isomers and vinyl chloride (VC) to ethene and ethyne were pH-dependent, and showed the reactivity order 1,1-DCE>VC> trans-DCE>cis-DCE. Similar results have been obtained by Lesage and colleagues [146]. Dror and Schlautmann [147, 148] have demonstrated the importance of specific core metals and their solubility for the reactivity of a porphyrin complex. 

Mass recovery of MA samples was checked by using the concentration (DRl) detector response (mass/area ratio) of the corresponding LB arm it was assumed that the detector response was identical for compositionally similar samples. Corrections for 38% and 9% sample loss were applied to the "mass injected" in the SEC/LALLS data for (Sl-1) DVB and (Sl-2) DVB, respectively. 

Definitions. The performance of a hydrocyclone is generally characterised by means of a grade efficiency or Tromp-curve which is the fractional mass recovery expressed as a function of particle size. 

Most cyclic and aryl nitronates are sohds at room temperature (41). However, the stability of aryl substituted nitronates is dependent on the configuration of the nitronate (40). For example, only the trans isomer of the ethyl nitronate of 4-nitrophenylnitromethane crystallizes from an analytically pure mixture of cis and trans isomers. The mass recovery reflects the percentage of the trans isomer in the original mixture. As expected, increasing substitution on the nitronate typically... 

Final sample mass (Aff) and initial concentrate mass, adjusted for expected adsorption losses (Aff), were used to calculate total mass recovery (see last column in Tables VIII-X). These values reflect efforts to correct recoveries for adsorption losses. 

Table XI. Model Solute Mass Recoveries Experienced in a SOX Concentration...

Table XII. Comparison of Volumetric Concentration, Organic Compound Concentration, and Trace Organic Mass Recovery Obtained in a Laboratory RO Concentration with the FT-30 Composite Membrane...

Chemical Class Model Compound Volumetric Concentration Organic Compound Concentration Organic Mass Recovery < )... 

Table III also presents our data for the extraction of Group 4 phenols from aqueous solutions. The o-bromophenol was added as an internal standard when some initial recovery problems were noted for the 2,6-di-terf-butyl-4-methylphenol results for its extraction are also reported here. The three phenols show good recoveries in the traps and overall good mass recoveries. One experiment was conducted under liquid C02 extraction conditions (temperature = 30 °C and pressure = 1500 lb/in.2) in an attempt to compare the relative efficiencies of the two states of CO2 for phenol extraction. Unfortunately, the phenols showed evidence of substantial breakthrough from the trapping system. The experiment does, however, demonstrate that liquid CO2 is also a good extractant for phenols present in water at parts-per-billion concentration levels.

SnSePh2)3 (0.395 g, 0.374 mmol) is pyrolyzed using the same method as that described for (Ph2SnS)3. A fine, dark gray powder of SnSe (144 mg, 36%) remained in the crucible while a 240-mg mixture of predominantly SnPh4 and Ph2Se is isolated from the end of the tube and from the liquid N2 trap (97% total mass recovery). 

As the concentration of EtOH increased from 0 to 10%, the effective steady-state mass transfer coefficient declined from 0.17 1/hr to 0.11 1/hr, which was due in part to the change in Darcy velocity. Using correlations developed for Ke,ss as a function of Darcy velocity and alcohol concentration (Taylor, 1999), the effect of EtOH concentration can be evaluated at a single, representative Darcy velocity. For example, using a Darcy velocity of 4.0 cm/hr, the value of Ke,ss would be 0.14, 0.13, and 0.13 for 4% Tween 80, 4% Tween 80 + 5% EtOH and 4% Tween 80 + 10% EtOH, respectively. Thus, the addition of EtOH to 4% Tween 80 had no discemable influence on the effective steady-state mass transfer coefficient. It should be recognized, however, that although the mass transfer coefficient remained essentially unchanged, the steady-state concentration of PCE in the column effluent (C") and the cumulative PCE mass recovery increased substantially as a result of EtOH addition (Table 2). This behavior can be explained by the fact that the equilibrium solubility of PCE (C" sat) increased by more than 50%, from 26,900 mg/L to 42,300 mg/L, with the addition of 10% EtOH. 

The mass recovery of a resolution is no more than 50% since half of the original mixture consists of an unwanted enantiomer. Because so much material is lost in a resolution, process chemists try to place a resolution as early in a synthetic route as possible. An early resolution minimizes the amount of time, effort, and reagents expended on carrying the unwanted enantiomer through the synthesis. 

Table I. Polystyrene Latices Used in Mass Recovery Testing...

Particle size distribution as well as an average particle size can be determined by HDC. One of the main limitations to an accurage determination of the particle size distribution (PSD) as well as to the range of applicability of HDC is the low mass recovery due to capture of particles bigger than 200 nm. Silebi and McHugh (5), in their analysis of the determination of particle size distribution by HDC, concluded that size distributions could be calculated accurately only for systems with particle sizes below about 300 nm due to poor recovery of larger particles. 

Mass recovery is calculated by comparing the peak area resulting from injection of a sample through the column with the peak area from injection of an identical sample through a by-pass. The areas under the chromatogram have been measured with a Zeiss M0P-3 (modular system for quantitative digital analysis). Mass recovery is evaluated from the following expression ... 

In the present work, mass recovery has been tested at different flow rates and ionic strengths for several particle diameters. The dependence on superficial velocity is reported in Figures 2 to 5. Recovery is improved as surfactant (sodium lauryl sulfate) concentration is increased from 1 to 6mM where maximum recovery of the larger particles is attained. 

When higher ionic strength eluant is used, flow rate does not significantly affect mass recovery if the particle diameter is less than 200 nm. For larger particles, mass recovery is maximum at low flow rate (0.6 to 0.8 ml/min. i.e., superficial velocity of 0.9 to 1.3 cm/min). 

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