6. Aerobic acetic acid bacteria (AAB) are typically employed for oxidative conversion of ethanol acetic acid. The fermenter exit stream is then sent through a series of distillation column to obtain acetic acid (a) In a typical fermenter, the head space (space above the liquid free surface) of the fermenter is filled with vapor containing acetic acid, ethanol, water and oxygen. Do you expect spontaneous vapour phase reaction of ethanol with oxygen to form acetic acid in the vapor space? Support your answer with an appropriate calculation (b) Consider a typical feed to the distillation column following the fermenter. For sake of simplicity, let us assume that the feed to the column contains only acetic acid and ethanol. The excess Gibbs free energy for Acetic Acid (1) - Ethanol (2) is given by G --2.1x, x, where xi and x2 are the mol fractions of RT components 1 and 2 in the liquid phase. The vapour pressures of components at 80C are 0.275 bar and 1,085 bar respectively. Derive expressions for activity coefficients of each component as functions of composition. Using the obtained expression, compute the equilibrium pressure and vapour phase composition in equilibrium with the liquid containing 60 mol % of acetic acid at 80C K