Column laboratory scale

Four column systems are available from Amersham Pharmacia Biotech that can be used to pack SEC media for various applications at the laboratory scale. These include C, XK, SR, and HR column systems. All of the laboratory-scale columns are constructed with borosilicate glass tubes. Columns for larger scale process applications include INdEX, BPG, EineLINE, BPSS, and Stack columns. The larger scale columns are constructed to meet stringent validation requirements for the production of biopharmaceuticals. Each of the column types are described. 

In order to determine rigorously the process parameters, a few relevant parameters are to be experimentally determined on a laboratory scale column. 

Laboratory scale columns tend to make important demands for new material and this fact, coupled with relatively long timescales needed for these studies, contributes to limit the number of small-scale experiments that can be successfully carried out [49, 50], resulting in full-scale processes which are however sub-optimal from both technical and economic perspectives. 

Chan and Fair (145) extended their correlation to multicomponent systems. Unfortunately, the extension was tested only against few data points, all derived from laboratory-scale columns. However, this extension represents a large improvement over most alternative theoretical correlations. 

Laboratory-scale column experiments, using two resin columns in series, were performed with feed solutions containing 25 g/L Pu, 90 mg/L Am, 6 M HNO3, 0 to 0.55 M F, and 0 to 0.19 M A1(N03)3. With a flow rate of 5 mL/cm. min, loadings of 100 to 120 g Pu/L resin were obtained on the first column. The effluent from the first column contained 11 to 22% of the Pu while that from the 2nd column contained 0.02 to 0.9% of the Pu. Washing with 5 M HNO3/... 

Acetone and methanol are impossible to separate by simple distillation due to the presence of an azeotrope. However, the addition of water near the top of a column allows these two components to be separated. Five sets of steady-state operating data for the extractive distillation of an acetone-methanol azeotrope in a laboratory scale column have been provided by Kumar et al. (1984). A schematic diagram of the column is provided in Figure 14.19. The column had a diameter of 15 cm and was fitted with 13 bubble cap trays, a total condenser and a thermosiphon (equilibrium) reboiler. Unlike many experimental distillation studies, these experiments were not carried out at total reflux the acetone-methanol feed entered the column on the eleventh stage from the top (the condenser counts as the first stage) and the water was introduced on stage six. The column was operated at atmospheric pressure for all five runs. Additional details of the column, operational specifications, and computed product compositions for one of these experiments can be found in Table 14.9. 

Arwickar (1981) reported some results for distillation under total reflux conditions of the system acetone-methyl acetate-methanol. The experiments were carried out in a laboratory scale column of 7.62 cm diameter packed with 0.635 cm Raschig rings. The simulation of total reflux operations using the nonequilibrium model is discussed by Krishnamurthy and Taylor (1985a). In simulations of Arwickar s experiments Taylor et al. used the correlations of Onda et al. (1968) to estimate the mass transfer coefficients in each phase and the effective interfacial area. The average absolute discrepancy between predicted and measured mole fractions was less than 2 mol% for acetone and methyl acetate and less than 4 mol% for methanol. 

Most reported applications have been for protein purification (28-30). One example (31) was for direct recovery of Annexin V, an intracellular recombinant protein, from E. coli homogenate, using the Streamline DEAE adsorbent (Pharmacia). The procedure was developed in a laboratory-scale column (50 mm diameter by 1000 mm length) and then successfully scaled to a pilot-plant column (200 mm diameter by 950 mm length). The yield was 95% for both laboratory and pilot-plant runs and achieved a threefold reduction in volume compared to the homogenate. 

The main problems associated with the use of the present model for large scale operation are that it was tested using laboratory scale columns and a "syrup" consisting of a solution of pure dextrose. 

Sundmacher et al. [20] used both EQ stage (with Murphree efficiency) and NEQ models to simulate the MTBE and TAME processes. The reactions were handled using both quasi-homogeneous and heterogeneous methods. Simulation results were compared to experimental data obtained in two laboratory-scale columns. A detailed NEQ model was needed to describe the TAME process, but both NEQ and the EQ stage (with an efficiency of 0.8) model could adequately represent the MTBE process. 

For the laboratory-scale column, the feed is at room temperature, while for the pilot-scale setup, the feed is preheated. 

A series of simulations was performed for the laboratory-scale column, and a very good agreement between simulated and experimental data was obtained (see... 

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