PRODUCTION OF ALCOHOL FROM SOURSOP JUICE AT DIFFERENT TEMPERATURES WITH EFFECT OF POTASSIUM SULPHATE AND AMMONIUM SULPHATE

Abstract

The production of alcohol from soursop juice at different temperatures was investigated to obtain certain useful thermodynamic parameters. This was achieved by the determination of the effects of temperature, substrate, potassium sulphate and ammonium sulphate on the rate of carbon (IV) oxide (CO₂) production. The extent of acceleration was examined by the addition of some potassium sulphate and ammonium sulphate. The results indicate that the rate of fermentation of soursop juice increased in proportion with temperature (optimum 36^oC), substrate (optimum 50%v/v), potassium sulphate (optimum 50%v/v) and ammonium sulphate (optimum 30%v/v) up to a limit and decreased. Suggesting that the reaction takes place in two steps (equilibrium and decomposition steps). The thermodynamic parameters determined are: enthalpy, H* 151.14 kJmol^-1; entropy of activation, S* 275.359 Jmol^-1k^-1; Gibb’s free energy of activation, G* -752.21 kJmol^-1 and Equilibrium constant K_eq, 1.4 respectively. These values were subsequently used to obtain by calculation Arrhenius constant A, 1.51x10²³ dm³mol^-1s^-1; orientation factor P, 1.41x10^-34 and the collision frequency, Z, 1.07x10¹¹ respectively. Finally, the suggested accelerators did not bring about marked increase in the rate of fermentation and yield as expected.