SMST Chemical Engineering Team Achieves New Progress in the Green Extraction of Bromine from Brine

Bromine is an important chemical raw material widely used in fields such as flame retardants, medicine, and pesticides. Currently, the industrial extraction of bromine from brine primarily employs the chlorine oxidation method. However, this method involves the storage and transportation of highly toxic chlorine gas, posing significant safety risks, and the production process may generate toxic halogenated organic by-products that threaten the ecological environment. Therefore, developing safe and environmentally friendly chlorine-free extraction technologies for bromine is crucial for promoting the green and sustainable development of the bromine chemical industry.

The Marine Chemistry and Chemical Engineering team at Tianjin University has collaborated with the Tianjin Research Institute for Seawater Desalination and Comprehensive Utilization under the Ministry of Natural Resources. They have innovatively employed hydrogen peroxide (H₂O₂) as a green oxidizing agent to successfully develop a chlorine-free process for the efficient production of sodium bromide from complex bittern systems. Under mild conditions, the process achieves a bromine utilization rate of up to 99.74% from brine with an initial bromine concentration as low as 1 g/L. Additionally, through an optimized air blowing and alkaline solution absorption system, they produced sodium bromide with a purity exceeding 99.5%. Importantly, the research team revealed the "catalytic" role of high concentrations of chloride ions (Cl⁻) in the brine during the reaction through kinetics and mechanism studies, illustrating how these ions significantly accelerate the oxidation of bromide ions by forming reactive intermediates, providing critical theoretical support for the efficiency of the process. The findings were recently published in Separation and Purification Technology (IF 9.0) under the title "Efficient production of bromine from low-concentration bittern using chlorine-free extraction process". The co-first authors of the paper are Chai Shujing (Ph.D. student) and Chang Heng (postdoctoral researcher) from the Marine College of Tianjin University, with Professor Su Rongxin and Senior Engineer Zhang Qizheng as the corresponding authors.

This work successfully develops a new hydrogen peroxide-based bromine extraction process that is safe, efficient, and environmentally friendly. This technology eliminates the safety and environmental risks associated with chlorine use at the source, providing a highly potential green alternative for bromine production and positively contributing to the sustainable development of marine chemical resources.