NAME: Machell Lee

ID #: 05714408

LABORATORY EXERCISE: EA1

LAB TITLE: Construction and Operation of Extraction system

GROUP: B

DEPARTMENT: Chemical Engineering

DATE PERFORMED: March 10, 2006

DATE SUBMITTED: March 17, 2006

Abstract

This experiment aims to construct and test a fixed bed leaching system for the extraction of solute from a bed of solids. Sorrel dye was extracted from dried sorrel using hot water according to the extraction apparatus shown. The apparatus was constructed by cutting the pipes to the required length and filing for an even smooth edge. The pipes were threaded to approximately eight joints and thread seal applied (in the direction of the thread).The apparatus was fitted with all the necessary equipment and the water bath was preheated and maintained at a specific temperature. The sorrel was fully immersed by the water recycling through the column. Samples were collected every 2 minutes for 20 minutes and the transmittance determined using the ThermoSpectronic Heλios α spectrometer.

It is evident from the graph that the % transmittance of the sample decreases with time. This corresponds with what is expected from theory. The sample becomes more concentrated with time as a result of the dye solution being continuously recycled though the dried sorrel. % transmittance measures the amount of light passing through the sample and is such a measure of the concentration of the sample. The more concentrated a solution is, then the less light will be transmitted through it as a greater number of solute molecules are present to obstruct the passage of light.

Results

Bottle Time/min % Transmittance1 2 54.512 4 49.463 6 43.244 8 39.925 10 37.916 12 33.227 14 30.248 16 29.049 18 26.4810 20 25.9

Table 1

Graph of % Transmittance against time for the extraction of sorrel dye

0

10

20

30

40

50

60

2 4 6 8 10 12 14 16 18 20

Time/min

% T

rans

mitt

ance