ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Eco-friendly approach to potassium sulfate syntheses: reaction mechanisms and optimization of the Et₂NH-H₂SO₄-H₂O system

Akbar Bobokulov, Aktam Erkayev, Dilafruz Eshmetova, Ilham Kholov, Saida Abdukarimova, Gulmira Tadjieva, Natarajan Elangovan, Elyor Berdimurodov, Muslum Demir, and Jasur Tursunqulov

Department of Chemical technology of inorganic substances, Tashkent Institute of Chemical Technology, Tashkent, Uzbekistan

E-mail: elyor170690@gmail.com

Received: 30 January 2025  Accepted: 4 April 2025

Abstract:

The growing demand for chlorine-free potassium sulfate, a vital fertilizer for chloride-sensitive crops, necessitates the development of sustainable and efficient production processes. This study investigates the Et₂NH-H₂SO₄-H₂O system to optimize the synthesis of diethylamine sulfate ((Et₂NH₂)₂SO₄), a critical intermediate in potassium sulfate production. Through systematic analysis, reactions were investigated across various molar ratios, focusing on the effects of temperature, pH, and aggregation states. Physical characterization confirmed the compound’s structural integrity, uniform composition, and high crystallinity, with key elements aligning closely with theoretical stoichiometry (56% carbon, 31.8% sulfur, 7% nitrogen, and 5.3% oxygen). Thermal stability studies using DSC/TG identified five distinct decomposition stages, with a total mass loss of 89.14%, providing crucial insights into its behavior under controlled conditions. The optimized Et₂NH:H₂SO₄ = 3:1 yielded pure (Et₂NH₂)₂SO₄ at a pH 3.41, facilitating scalable, eco-friendly production methods. The present study, for the first time, fully explores the reaction mechanism and optimization of diethylamine sulfate synthesis in given system, marking a significant advancement over existing methods. By eliminating the need for high-temperature furnaces and reducing energy consumption, the optimized process minimizes environmental impact while enabling scalable industrial production of potassium sulfate. These findings underscore the importance of this study in addressing agricultural, environmental, and industrial challenges, paving the way for eco-friendly and efficient fertilizer production.

Keywords: Catalyst Synthesis; Chemical Synthesis; Green Chemistry; Industrial Chemistry; Process Chemistry; Synthetic Chemistry Methodology; Diethylamine sulfate; Sulfuric acid; Chlorine-free potassium sulfate; Thermal stability; Crystalline properties

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04055-y

Chemical Papers 79 (7) 4261–4274 (2025)