Design of a Plant to Produce 20,000 Litres/Day of Citric Acid from Corn Cob Using Aspergillus niger

Abstract

There has been a considerable interest in utilizing natural agricultural waste materials for the creation of value-added products, such as citric acid, as a more environmentally friendly substitute for sugar molasses. This report describes the plan for a facility that can produce 20,000 liters of citric acid per day by employing Aspergillus niger to convert corn cob, which is a rich source of lignocellulosic material containing cellulose, hemicellulose, and lignin. These components can be broken down into fermentable sugars for the production of citric acid through submerged fermentation using the fungus Aspergillus niger. This particular technology was selected as the most suitable option, yielding citric acid as the primary product and dry distillery grain as a secondary product. To fulfill the design objective of ensuring high-quality citric acid while minimizing operational, capital, and maintenance costs, and maximizing profit, the plant is designed to produce 20,000 liters of citric acid and 19,942.32 kg of dry distillery grain per day. This requires a daily input of 29,376.30 kg of corn cob and 33,716.85 kg of water. The energy balance indicates that the process is exothermic, generating 4.510 MW of power. The proposed plant design offers a sustainable and cost-effective approach to producing citric acid from corn cob using Aspergillus niger.