Design of China first pilot plant for supercritical hydrothermal synthesis of AgNPs

Supercritical hydrothermal synthesis (SCHS) is an eco-friendly and efficient method for synthesizing nanomaterials. China's first pilot plant for SCHS of silver nanoparticles (AgNPs) has been successfully built, producing AgNPs with controllable particle sizes through reactor and system optimizations. This manuscript systematically explores the challenges of low heating and mixing efficiency and clogging, and proposes targeted solutions, including efficient warming, heat reuse and mixer structure optimisation. The detailed system components, evident properties, advanced control methods and primary experiment results of the pilot scale plant are described objectively, achieving high-purity AgNPs with an average particle size of 36.1 nm. These findings will contribute to the commercialisation of the SCHS pilot plant for continuous batch production of nanoparticles.