Techno-economic analysis and environmental impact assessment of citric acid production through different recovery methods

Evaluating the technical feasibility and economic viability of citric acid production at the commercial scale is challenging because it depends on several factors including type of feedstock, process parameters and production routes. In this research, techno-economic and environmental impacts of citric acid production from corn are comparatively evaluated for three scenarios. In the production process Aspergillus niger is used for corn fermentation in a commercial scale of 6400 kg/h citric acid production rate. The scenarios are defined based on application of three recovery methods, including calcium precipitation, solvent extraction, and ion exchange. From three investigated scenarios, the lowest selling price of citric acid is achieved in a scenario using solvent extraction recovery method, followed by the scenario with calcium precipitation recovery method. Sensitivity analysis shows that the minimum selling price of citric acid is highly sensitive to electricity cost, by-product credit, corn supply cost, fermentor cost and wastewater treatment cost. Environmental impacts of citric acid production in three scenarios are assessed using the life cycle assessment approach. Citric acid production with ion exchange recovery method is the most environment-friendly scenario. The results of this research are useful for the development of citric acid production in commercial scale. (C) 2019 Published by Elsevier Ltd.