Chemical Engineering Transactions (Nov 2023)
Improving the Sustainability of Acetone Recovery
Abstract
The recovery of solvents from waste solvent mixtures is important both from an economic and environmental point of view. In this work, the recovery of acetone from an aqueous mixture containing small amounts of organic pollutants by batch distillation is studied. The organic pollutants are removed in a fore-cut, which is incinerated, but with a considerable loss of acetone. Acetone is obtained in the main cut, while the acetone content of the still residue is reduced by taking an after-cut. The still residue is treated biologically as wastewater. The effects of the operational parameters (reflux ratios of the steps, stopping criterion of taking the fore-cut) on different sustainability indicators are studied. These indicators include the profit of a batch, the specific energy demand, the CO2 emission resulting from incineration and the generation of heating steam, wastewater generation and potential environmental impacts determined by the WAR algorithm. Based on the effects of the parameters, a new operational policy is proposed that has both a higher profit (by 60%) and lower environmental impacts (73% lower specific CO2 emission) compared to the base case.