d with a measured amount of tap water. This mixture was shaken until well mixed and allowed to settle. The procedure was repeated several times and for several different mixtures. The mixtures were considered to be in equilibrium and the acid concentration in the aqueous phase was measured. Rather than titrate the aqueous phase to determine concentration a chart was developed to correlate the aqueous pH value with the concentration. This was accomplished by taking the pH of known water-benzoic acid mixtures and preparing the graph below: Figure. 1From this graph it was easy to determine benzoic acid concentrations from the pH of a solution. Knowing the benzoic acid concentration of the aqueous phase in equilibrium with the kerosene feed the concentration of the acid in the kerosene could be determined from the following chart developed by Allerton (1943): Figure. 2Knowing the concentrations of the benzoic acid in both the aqueous and organic phases for the system at equilibrium. The concentration of the feed kerosene can be determined assuming the all of the benzoic acid in the system came from the kerosene feed exclusively. Knowing the concentration in the feed kerosene we began to run the process. First the water was used to fill the column to the top stage. The water entered from the top and exited from the bottom. For the process to be at steady state the water flow in the inlet and exit streams needed to be constant and equal. Because the only flow meter for the water was on the inlet we adjusted the water level in the tank using the inlet and outlet valves until it remained constant. With the water level constant we introduced the kerosene feed into the system. This was done slowly so that adjustments to the water flow could be made to keep the water level constant. Once the kerosene and the water were flowing with a constant water level the pH of the aqueous extract was measured at ten minute intervals until it t...
