Related Experiment Video
Updated: Oct 6, 2025

Two-way Valorization of Blast Furnace Slag: Synthesis of Precipitated Calcium Carbonate and Zeolitic Heavy Metal Adsorbent
Published on: February 21, 2017
Conversion of Calcium Citrate to Citric Acid with Compressed CO2
Rong Ye1, Zirui Zhao1, Rong Gao1
1State Key Laboratory of Bioreactor Engineering, Department of Bioengineering, East China University of Science & Technology, 130 Meilong Road, Shanghai 200237, China.
Abstract:
Citric acid is mainly produced in the fermentation industry, which needs complex processes and produces a high amount of CaSO4 as waste. In this study, CO2 has been used to convert calcium citrate to citric acid and CaCO3 by controlling the reaction parameters (reactants ratio, temperature, and pressure). The CaCO3 produced in this conversion could further be used in the fermentation industry for citric acid production. The transformation condition has been optimized by controlling temperature, pressure, reaction time, and mass ratio of calcium citrate and water. The highest conversion could reach up to 94.7% under optimal experimental conditions of 18 MPa of pressure, 65 °C of reaction temperature, 4 h of reaction time, and 2 g/L of calcium citrate/water suspension solution. This method features simple process, easy separation of citric acid, and environmentally friendly process, which could be a potentially alternative route for downstream treatment in fermentation production of citric acid.
Related Concept Videos
The Citric Acid Cycle
Products of the Citric Acid Cycle
The Citric Acid Cycle: Overview
The citric...
The Citric Acid Cycle: Output
Regulation of Citric Acid Cycle
The citric acid cycle is regulated in several ways, including feedback inhibition, regulation of enzyme activities, and associated anaplerotic or cataplerotic pathways.
The primary substrate of the TCA cycle—acetyl CoA—is...
Loss of Carboxy Group as CO2: Decarboxylation of Malonic Acid Derivatives
Loss of Carboxy Group as CO2: Decarboxylation of β-Ketoacids

