Liquid Liquid Extraction Essay -- essays papers

Liquid Liquid Extraction We were asked to extract benzoic acid from a kerosene-benzoic acid mixture. This was to be done using the stirred liquid-liquid extraction column in the senior laboratory. Fresh water was used as the continuous phase in the extraction. We were asked to measure the benzoic acid concentrations of the feed, raffinate, and extract streams. These measurements were to be made at several different steady-states. The number of theoretical stages and the height of the theoretical stages (HETS) was also to be determined. Because the liquid-liquid extraction column had not been used in several years our assignment also included discussing any problems with the process and possible solutions. The discussion of equipment, results, and experimental procedure will be discussed in the following paper entitled "Liquid-Liquid Extraction.† Even though the process had not been used in several years, everything worked very well. The flow meter used to measure the water flow rate had a small leak which was easily remedied using a bucket. One of the storage tanks still had approximately 400 liters of kerosene with a benzoic acid concentration of 0.00208 (gm/mL). Using this as a feed for the process, concentrations of benzoic acid in the aqueous extract were found to be 0.00109 (gm/mL) and 0.000783 (gm/mL) for two separate steady state experimental runs. The flow rates of the kerosene feed for the two steady states were 0.361 (gal/min) and 0.157 (gal/min) respectively. The number of theoretical stages for a flow rates of 0.361 (gal/min) and 0.157 (gal/min) were determined to be 1.76 and 0.87 stages respectively. With the height of the column equal to 48.9 inches the HETS for the two steady state conditions were 27.71 inches and 56.42 inches respectively. Transferring the benzoic acid from the kerosene into the water was accomplished without any major problems. The equipment worked very well except for minor problems with the water flow meter. After working on the process we would recommend that it be used more often. We also believe the results obtained from our experiments are accurate and well within experimental error. SUMMARY Liquid-Liquid Extraction of Benzoic Acid The number of theoretical stages and the height of the equivalent theoretical stages were determined for a liquid-liquid extraction proce... ... state conditions to have given good separations. We also believe the correlation between the pH of the aqueous benzoic acid solution and the actual acid concentration to be accurate. We recommend that the liquid-liquid extraction column in the senior laboratory be used more. The process is very interesting and appears to work well. Nomenclature Symbol Definition Units Xf Concentration of benzoic acid in the feed kerosene (gm/mL) Xr Concentration of benzoic acid in the raffinate (gm/mL) Ys Concentration of benzoic acid in the extract (gm/mL) m slope of the equilibrium line dimensions e extraction factor dimensions N number of theoretical stages dimensions Zt actual height of experimental column (inches) HETS height of equivalent theoretical stages (inches) References Robbins, L. A., â€Å"Liquid-Liquid Extraction†, in Perry’s Chemical Engineers’ Handbook, Sixth Ed., D. Green and R. H. Perry, McGraw Hill, New York, NY, p 51-1, (1984) Allerton, J., â€Å"Liquid Extraction in Perforated-Plate and Packed Towers.† American Institute of Chemical Engineers. 39:361-384 (1943). Liquid Liquid Extraction Essay -- essays papers Liquid Liquid Extraction We were asked to extract benzoic acid from a kerosene-benzoic acid mixture. This was to be done using the stirred liquid-liquid extraction column in the senior laboratory. Fresh water was used as the continuous phase in the extraction. We were asked to measure the benzoic acid concentrations of the feed, raffinate, and extract streams. These measurements were to be made at several different steady-states. The number of theoretical stages and the height of the theoretical stages (HETS) was also to be determined. Because the liquid-liquid extraction column had not been used in several years our assignment also included discussing any problems with the process and possible solutions. The discussion of equipment, results, and experimental procedure will be discussed in the following paper entitled "Liquid-Liquid Extraction.† Even though the process had not been used in several years, everything worked very well. The flow meter used to measure the water flow rate had a small leak which was easily remedied using a bucket. One of the storage tanks still had approximately 400 liters of kerosene with a benzoic acid concentration of 0.00208 (gm/mL). Using this as a feed for the process, concentrations of benzoic acid in the aqueous extract were found to be 0.00109 (gm/mL) and 0.000783 (gm/mL) for two separate steady state experimental runs. The flow rates of the kerosene feed for the two steady states were 0.361 (gal/min) and 0.157 (gal/min) respectively. The number of theoretical stages for a flow rates of 0.361 (gal/min) and 0.157 (gal/min) were determined to be 1.76 and 0.87 stages respectively. With the height of the column equal to 48.9 inches the HETS for the two steady state conditions were 27.71 inches and 56.42 inches respectively. Transferring the benzoic acid from the kerosene into the water was accomplished without any major problems. The equipment worked very well except for minor problems with the water flow meter. After working on the process we would recommend that it be used more often. We also believe the results obtained from our experiments are accurate and well within experimental error. SUMMARY Liquid-Liquid Extraction of Benzoic Acid The number of theoretical stages and the height of the equivalent theoretical stages were determined for a liquid-liquid extraction proce... ... state conditions to have given good separations. We also believe the correlation between the pH of the aqueous benzoic acid solution and the actual acid concentration to be accurate. We recommend that the liquid-liquid extraction column in the senior laboratory be used more. The process is very interesting and appears to work well. Nomenclature Symbol Definition Units Xf Concentration of benzoic acid in the feed kerosene (gm/mL) Xr Concentration of benzoic acid in the raffinate (gm/mL) Ys Concentration of benzoic acid in the extract (gm/mL) m slope of the equilibrium line dimensions e extraction factor dimensions N number of theoretical stages dimensions Zt actual height of experimental column (inches) HETS height of equivalent theoretical stages (inches) References Robbins, L. A., â€Å"Liquid-Liquid Extraction†, in Perry’s Chemical Engineers’ Handbook, Sixth Ed., D. Green and R. H. Perry, McGraw Hill, New York, NY, p 51-1, (1984) Allerton, J., â€Å"Liquid Extraction in Perforated-Plate and Packed Towers.† American Institute of Chemical Engineers. 39:361-384 (1943).