Assignment:
Oil is to be extracted from soybeans. The beans can be assumed to be 20 wt% oil (O) and 80 wt% solids (S). Beans are fed to an extraction tank along with liquid n-hexane (H) in a 1:4 ratio. The extraction tank effluent passes through a filter where all of the solids are recovered in the filter cake. The filter cake is 70 wt% solids and the balance is oil and hexane, which are in the same ratio that they emerge from the extraction tank. The liquid that passed through the filter (called the filtrate) is fed to an evaporator. The hexane is vaporized and separated from the oil product. The hexane vapor is cooled, condensed, and recycled back to the extractor where it is mixed with a fresh feed of hexane.
a. Calculate the overall yield of oil product (kg oil produced/kg beans fed).
b. Calculate the required fresh hexane feed (kg fresh hexane/kg beans fed).
c. Calculate the recycle to fresh feed ratio (kg hexane recycled/kg fresh hexane).
d. How many lbs (pounds) of oil would be produced if 100 lbs of beans are fed to the process?
