performance evaluation of microfiltration and centrifugation for separating suspended solids from fermented molasses solution

Ethanol is considered a renewable fuel that can be produced via fermentation of sugarcane molasses. the fermented solution that is fed to the distillation column has suspended solid content that tends to block distillation trays leading to low ethanol recovery. in this study, performances of microfiltration and centrifugation processes were investigated for the separation of suspended solids from the fermented solution of sugarcane molasses. the filtration process using a ceramic filter under pressure differences of 1, 2, 3, and 4 bars was studied. based on the results of this study, the overall filtration process can be divided into three stages pore blocking, cake filtration, and cake layer compression which were more pronounced as pressure difference across filter media increased. in addition, increasing pressure difference across the filter caused a sharp decrease in permeate flux due to faster pore blocking and higher turbidity removal, 96.99% due to cake filtration, and compaction of the cake layer. a comparison of curve-fitted experimental data and blocking models showed that the full cake model had the best fit with an average absolute relative error (aare) of 0.112. further, in this study, experimental design was used to optimize the operating parameters of centrifugation for separation and removal of suspended solids from fermented solution. single complete and complete-standard models among blocking models had the best fit for filtration after centrifugation under optimal operating conditions that correspond to the filtration pressure difference of 4 bars. the measured data showed that the permeate volume in centrifugation plus filtration increased about threefold compared to filtration alone, although the turbidity removal decreased slightly from 96.99 to 89.78%.