Production of Sodium Nitrite Based on Staged Absorption of Nitrous Gases Using a Solution of Tributyl Phosphate and Iron Sulfur Oxide

Abstract

The manuscript presents a comprehensive study on the development of a stepwise absorption method for nitrogen oxides using tributyl phosphate (TBP) and iron sulfate solutions, aimed at efficient sodium nitrite production. The work is scientifically significant as it addresses the environmental and industrial challenges associated with nitrogen oxide emissions, converting hazardous gases into a valuable chemical product. The research demonstrates the optimization of absorption conditions, such as solvent composition, temperature, and the ratio of TBP to iron sulfate, achieving an absorption efficiency up to 99.91%, with subsequent regeneration of absorbents and production of high-purity sodium nitrite (99.2% mass fraction). The study is methodologically robust, employing laboratory-scale experiments, systematic stepwise absorption in multiple absorbers, and advanced analytical techniques including IR spectroscopy to validate the quality of the synthesized sodium nitrite compared to imported standards. The results are practically relevant for the chemical industry, providing an environmentally friendly and economically efficient approach to nitrite production, while minimizing toxic gas emissions and energy consumption. Moreover, the proposed method has potential implications for industrial scalability and the sustainable production of sodium nitrite, which is essential in food, pharmaceutical, and chemical applications. Overall, this manuscript offers a valuable contribution to both scientific understanding and industrial practice by integrating fundamental research on nitrogen oxide absorption with practical applications in sodium nitrite synthesis, and it provides a foundation for further studies on optimizing multistage gas absorption technologies.