Simulating the Liquid-Liquid Extraction of Acetic Acid during - - PowerPoint PPT Presentation

Simulating the Liquid-Liquid Extraction

• f Acetic Acid during Wastewater

Treatment using Aspen Plus

Joe Shangraw

Materials Science and Engineering 2022

Background

• Wastewater treatment makes up around 20-40%
• f many local government energy budgets
• 3-4% of all energy consumption is for water

treatment, totalling over 45 million tons of GHG emissions (EPA)

• This creates the demand for an energy efficient

method of extracting high value products from waste

https://www.tpomag.com/online_exclusives/2019/01/wastewat er-treatment-plants-could-become-sustainable-biorefineries

The Big Picture

• The Department of Energy is sponsoring projects at several labs and

universities across the country

• The goal is to develop a system to convert food waste and sewage

into valuable volatile fatty acids (VFAs)

Pretreatment of Sewage and Food Waste Converting waste into VFAs Extraction of VFAs from aqueous stream

Former Research at U of M

Developed CLEANS extraction method:

• Liquid-liquid extraction of

carboxylic acids

• Assisted by novel,
• leophobic membrane

Diagram of CLEANS process (made by David Speer)

UROP Summer Project

Model the CLEANS method using the Aspen Plus Chemical Process Simulator

• Observe how solvent choice and concentrations affect the rate of

extraction

• Focus on reaction between acetic acid and the extractant

Benefits of an accurate simulation

• Quicker way to screen potential solvents and extractants for optimization
• f concentrations

Acetic Acid and Extractant Reaction

+

Extractant complex

(Tamada and King 1990)

Acetic Acid Trioctylamine (extractant)

Aspen Plus Simulation

Example Flowsheet of Extraction Reactor

Molecule builder for chemicals not in the Aspen Database Stream summary of both inputs and outputs after running the simulation

Validating Simulation against Previous Research

Extraction of acetic acid with trioctylamine (TOA) in chloroform (Wardell and King, 1978) Extraction of acetic acid with TOA in toluene (Sprakel and Schuur, 2019)

Chloroform (Active solvent) Toluene (Inactive solvent)

Simulations Published experiments

0.2 M 0.17M

Errors in Results

• Aspen Plus cannot always predict properties of molecules that are

not in the database, especially when they have charges

• The interactions between the molecules and the solvents are more

complex than what can be entered for an Aspen reactor, especially with active solvents such as chloroform.

Future Work

• Explore other simulation software with different mechanisms

○ Could provide more accurate results than Aspen Plus

• Return to the lab to run the extraction in person
• Continue to review previous literature to choose the most effective

solvents and extractants

References

1. Environmental Protection Agency (2015). Energy Efficiency in Water and Wastewater Facilities. Retrieved from https://www.epa.gov/sites/production/files/2015-08/documents/wastewater-guide.pdf 2. Tamada, J. A., & King, C. J. (1990). Extraction of Carboxylic Acids with Amine Extractants 2: Chemical Interactions and Interpretation of Data. Ind. Eng. Chem. Res., 29, 1327-1333 3. Wardell, J. M.; King, C. J. (1978). Solvent equilibria for extraction of carboxylic acids from water. J. Chem.

• Eng. Data, 23(2), 144-148.

4. Sprakel, L. M. J., & Schuur, B. (2019). Solvent developments for liquid-liquid extraction of carboxylic acids in

• perspective. Separation and purification technology, 211, 935-957.