1. In the production of bean oil, beans containing 30 wt% oil and70 % solids are ground and fed to a mixing tank, where they aresuspended in liquid n-hexane (C₆H₁₄). Thefeed ratio is (6 kg hexane/kg beans). Essentially all of the oil inthe beans is extracted into the hexane. The mixer effluent passesto a filter. The filter cake contains 90 wt% bean solids and thebalance bean oil and hexane. The liquid filtrate emerging from themixer has the same composition as the liquid components in thefilter cake. The filter cake is discarded, and the liquid filtrateis fed to a vacuum evaporator, in which the hexane is totallyvaporised and thereby separated from the oil. The hexane vapour issubsequently condensed and recycled to the mixing tank.

(a) Draw a flowchart of theprocess for the extraction of bean oil.

(b) Calculate the yield of beanoil product (kg oil/kg beans fed), the required fresh hexane feed(kg C₆H₁₄/kg beans fed), the recycle to freshfeed ratio (kg hexane recycled/kg fresh feed), and the compositions(component mass fractions) of the slurry leaving the extractor andthe filtrate.

(c)Suggest possible changes in process conditions or additionalprocessing steps that might improve the performance and overalleconomy of this process.