In an era where sustainability is paramount and environmental consciousness drives innovation, the quest for eco-friendly practices within various industries has become imperative. This project is an ethanol recovery project, aims to recover ethanol from expired liquid soap and distill it to 95% purity which is able for sale. This initiative not only minimizes waste production but also creates certain economic value by recovering valuable products from waste. 

    An experiment were conducted before process flow design for simulations of production. The liquid soap contains 65% ethanol, 35% water and other substances. During the pilot test, it was observed that the a large amount of foam is produced during the distillation of liquid soap. However, when the ethanol reaches a certain concentration, the foam naturally subsides.

    Based on this phenomenon, it was determined to adopt a staged distillation process to reduce the usage of defoamers. The first stage of distillation serves as the primary distillation, handling larger quantities, and utilizing a relatively larger tower structure. After recovering a certain amount of ethanol in the first stage of distillation, it enters the second stage. In this stage, as the ethanol concentration decreases, foam is generated during the distillation process. Therefore, a certain amount of defoamer is added at this stage.  

    The equipment operates very successfully, with ethanol recovery concentrations reaching up to 95%.

   The ethanol recovery system consists of the following main components:

1). One primary distillation tower, which is a packing tower, and equipped with necessary material distributors; 

2). One secondary distillation tower, which is a packing tower, and equipped with necessary material distributors as well;

3). One metering system, controls the consumption of defoamers;

4). One PLC system enables the automation operation of the system, while a DCS system can also be employed to achieve more possibilities and flexibility in operation.