Question

Oil is extracted from mustard seeds having 20 wt% oil and 80 wt% solids, using hexane as a solvent. After extraction, the hexane-free residual cake contains 1 wt% oil. Assuming negligible dissolution of cake in hexane, the percentage oil recovery in hexane is ___________ % (rounded off to the nearest integer).

Hint:

Calculating oil recovery efficiency is critical in evaluating the performance of the extraction process and optimizing solvent use.

Answer 1

Step 1: Calculate Initial and Remaining Oil Content. Initial oil content = 20% of 100 kg = 20 kg.
Oil remaining in cake = 1% of 100 kg = 1 kg. 
Step 2: Calculate the Oil Extracted and Percentage Recovery. Oil extracted = Initial oil - Remaining oil = 20 kg - 1 kg = 19 kg.
Percentage recovery = \(\left(\frac{19 { kg}}{20 { kg}}\right) \times 100% = 95%\).