Column Cl

Condenser Use the drop-down menu to select Total. If the distillate is removed as a vapor, Partial-Vapor should be selected. 

Reboiler Both the kettle and thermosyphon reboilers are partial reboilers (the vapor from the reboiler is in equilibrium with the liquid bottoms product withdrawn), so it does not matter which you select. 

Convergence The Standard method works well in hydrocarbon systems. Alternative methods must be used in highly nonideal systems. Examples in latter chapters will illustrate this. 

Bottoms rate Reflux rate Boil up rate Boil up ratio Distillate to feed ratio Bottoms to feed ratio Condenserdu ReboiierduV  

C3 DeslgiSp s -Q vary O Healers GoolefS Ca Pumpa ounds 

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Some small amount of byproduct formation occurs. The principal byproduct is di-isopropyl ether. The reactor product is cooled, and a phase separation of the resulting vapor-liquid mixture produces a vapor containing predominantly propylene and propane and a liquid containing predominantly the other components. Unreacted propylene is recycled to the reactor, and a purge prevents the buildup of propane. The first distillation in Fig. 10.3a (column Cl) removes... 

Enter the appropriate code for the influent concentration (in column Cl for the first treatment step in the sequence. Leave this item blank for the rest of the treatment steps in the sequence. 

With on-line techniques, the column switching operations are done using valves. Fig. 5.3d shows a simple arrangement for zone cutting that could be used for sample clean-up. The zone marked Y is to be determined and all other zones are to go to waste (this type of cut is called a heart cut). Initial separation takes place on column Cl so that early zones (X) are routed to waste. When zone Y is eluted from Cl, valve V2 is switched to elute this zone onto column C2. After complete transfer of Y onto C2, valve VI is switched to prevent further elution of unwanted zones (Z, for instance). Zone Y is eluted to the detector and Cl can be cleaned and re-equilibrated with mobile phase. 

ATP Luciferin-luciferase Phosphate buffer (pH 7.8) End-column CL detection 5 nM 84... 

Figure 9 End-column CL detector for CE proposed by Zare s group. (From Ref. 84, with permission.)...

In a 40-mm.-diameter column (Cl) with 3-in. plate spacing and %4-in. holes whose total cross section was about 6% of the column cross section, and with the system acetic acid-methylisobutyl ketone-water, ketone dispersed, the best extraction rates occurred at a total liquid flow of 35.6 cu. ft./(hr.)(sq. ft.), 29 cycles/min., and 4-mm. amplitude. The HETS was 10 in., corresponding to a total throughput/volume of a theoretical stage of 42.1 hr.-1. Similarly in a 1.5-in. column (B2) with plates on a 1-in. spacing and containing ) 2-in. holes whose area was 23% of the column cross section, pulsed at 28 cycles/min., 6-mm. amplitude, with the same system, the HETS was 2.59 in. at a total liquid flow... 

Unusually high pressure in column Cl (we need to investigate why... 

Because of the cobalt(II) contamination, the perchlorate salt is synthesized and then converted to other salts. Cobalt(II) chloride 6-hydrate (1.0 g, 4 mmole) and free [15]aneN4 (05 g, 4.2 mmole) are warmed in 100 mL of methanol for 15 minutes. Concentrated hydrochloric add is added dropwise (1 mL) and air is bubbled through the solution for at least 2 hours. Several drops of perchloric acid are added to precipitate the products as the perchlorates. The yield is 72%. The product is brown and is about 90% pure isomer I. The brown perchlorate salt is dissolved in acetonitrile and passed through a Dowex 1X8,200-400 mesh anion exchange column (Cl form) at a rate of 10 sec/drop. The eluent is concentrated by rotary evaporation. Some green solid (isomer II) precipitates. This is filtered and the volume of the filtrate is further reduced to precipitate the tan isomer (I) as the chloride salt. Yield 60% Anal. Calcd. for CoC2r H26N4a3 C, 34.80 H, 650 N, 14.76. Found C, 34.35 H, 7.09 N, 14.50. 

Fresh aqueous ethanol feed is first preconcentrated to nearly the azeotropic composition in column C3, while producing a water bottoms product. The distillate from C3 is sent to column Cl, which is refluxed with the entire organic (entrainer-rich) layer, recycled from a decanter. Mixing of these two streams is the key to this sequence as it allows the overall feed composition to cross the distillation boundary... 

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