Title
Evaluation of organic acids as scrubbing agents for ammonia recovery from wastewater through Aspen Plus® simulations
Author
Huang, Wenqing (TU Delft Civil Engineering & Geosciences)
Contributor
Spanjers, H. (mentor) 
van Lier, J.B. (graduation committee)
Mutahi, G. (mentor)
Degree granting institution
Delft University of Technology
Programme
Civil Engineering
Date
2023-11-08
Abstract
This study evaluates the effectiveness of organic acids, specifically citric acid, lactic acid, and malic acid, as scrubbing agents for ammonia (NH3) recovery from waste air streams. The acid scrubbing process was modeled using Aspen Plus® and validated against sulfuric acid scrubbing process data available in the literature. The effects of various system variables, such as temperature, gas liquid ratio (G/L) pressure, acid and NH3 concentrations, on the scrubbing efficiency as well as outlet ammonium ion mass flow rate was investigated. Results showed that reducing temperature, acid reflux ratio, G/L ratio, and inlet NH3 concentration while increasing pressure and inlet acid concentration can improve scrubbing efficiency. Citric acid exhibited the highest ammonia removal rate, the lowest acid consumption, and the least change in scrubbing efficiency when changing inlet ammonia concentration, followed by malic acid and lactic acid. These findings suggest that citric acid is a promising alternative to sulfuric acid as a scrubbing agent for NH3 recovery in wastewater treatment plants. This study needs to further incorporate the dissociation reactions equations of organic acids to provide accurate results. Additionally, the simulation's simplification in the design of the scrubber system introduces uncertainties in the results.
Subject
Ammonia recovery
Organic acids
Acid scrubbing
Wastewater
Circular economy
To reference this document use:
http://resolver.tudelft.nl/uuid:fb6f2000-fd5d-4c58-960e-834d76c74a61
Embargo date
2025-11-22
Part of collection
Student theses
Document type
student report
Rights
© 2023 Wenqing Huang