Our country's research has proposed a preparation technology for insoluble sulfur based on microbubble enhanced quenching, with an extracted product containing as much as 97.33% IS content.

Insoluble sulfur, due to its characteristics of uniform dispersion and high self-adhesiveness, is widely used in the production of high-performance green tires. Recently, a research team at the Qingdao Institute of Bioenergy and Process Research, Chinese Academy of Sciences, has developed a new rapid quenching method based on microbubble technology. The swirling adiabatic injector designed by the research team adopts a composite structure of stainless steel and glass. By introducing high-temperature gaseous sulfur axially and tangentially injecting quenching liquid, the device achieves efficient heat transfer between gas and liquid phases with a large temperature difference. The device disperses high-temperature sulfur vapor into tiny bubbles within milliseconds of contact time, directly generating uniform particle size IS powder products, while eliminating the traditional crushing process. The research team conducted a systematic investigation on the influence of process conditions, stabilizer types, and additions on the IS content and thermal stability at 105 using the newly developed swirling adiabatic injector as the key quenching equipment. The results showed that the extracted IS content of the product reached 97.33%, and the thermal stability of oil-filled product IS reached 86.49%. The swirling adiabatic injector demonstrated excellent quenching effect, providing an ideal quenching equipment for the continuous industrial production of high-quality insoluble sulfur. The related research results were published in the Journal of Process Engineering. The research was supported by the National Key Technology Research and Development Program.