Regeneration factor, column

Factors Controlling Selectivity Open Tubular Columns Dynamic Coating Static Coating Column Regeneration Capillary Column Design and Choice Stationary Phases for the GC Separation of Chiral Substances Synopsis References Chapter 6... 

Another factor increasing the cost of distillation in ion exchange regenerant recovery is the need for supplying reflux to the rectifying columns. The boil-up for the reboilers is the distillate product plus the reflux, where in direct distillation the reboiler has to vaporize only the product. 

Figures 9 and 10 illustrate changes in two dependent variables dynamic N2 adsorption capacities and CH4/N2 separation factors. Independent variables are column temperature, operating pressure, and time allowed for vacuum regeneration. This experimental series used a constant feed rate of 6.0 1/min over a time of 1.00 min into a 1" dia. x 24" long adsorber filled with 180g of zeolite. Column depressurization took place for 1.00 min. and this was followed by a variable length vacuum regeneration.

K approx 0.8 g/L). The requirement for a high binding affinity and capacity at low concentration can be partially addressed by use in a packed column as discussed later. Total capacity and regenerability then are critical factors. Since the possibility of in situ separation was being considered, the effect of the substrate glucose was also used to screen sorbents. 

Two resins were tested for the removal of succinic acid from simulated medium on a packed column of sorbent to simulate an actual process on a small scale. It is important to test the sorption with medium, because salts and other nutrients can interfere with the sorption. Table 4 presents the results for XUS 40285 MWA-1 was comparable. This indicates that either sorbent can remove succinic acid efficiently from the fermentation broth without direct loss of product. Both columns were then stripped or regenerated with hot water. Stripping with hot water recovered 70-80% of the succinic acid from the XUS 40285 resin whereas less (50-60%) was recovered from the MWA-1. The XUS 40285 column was stripped with 2 column volumes of hot water with eluent concentrations up to 49 g / L. Succinic acid was concentrated on average to 40 g/L in the XUS resin by this operation and to 30 g/L by the MWA-1. The 10-fold concentration factor bodes well for the use of sorbents to purify the fermentation broth. 

Experiments with simulated waste indicate that we can process approximately 20 column volumes through one Duolite column and obtain decontamination factors of about 10 -10 . We expect this to be sufficient, but, if necessary, we can obtain higher decontamination factors by processing less feed before regeneration or by using a second cycle. 

Any comparison between the production rates achieved with the same chromatographic system (but not the same column, nor necessarily the same mobile phase composition) in the elution and displacement modes is biased by the lack of clear estimates of the cycle time in the displacement mode. The time required for regeneration of the column must be factored in. This time cannot be less than a few times to, and can be as high as the displacer retention time at infinite dilution. 

Reduction of the costs for column regeneration, and waste water treatment was observed. High recovery factor up to 90% was obtained in the RO concentration step, with final concentrations higher than 80 g/1. 

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