Latest Trends in Supercritical Fluid Technology: Next-Generation Processes Driving Decarbonization, Environmental Purification, and Material Innovation

Astamuse Inc. (Headquarters: Chiyoda-ku, Tokyo; Representative Director and President: Ayumu Nagai) has comprehensively analyzed the technology domain of supercritical fluids using its proprietary innovation database (covering innovation and R&D information such as academic papers, patents, startups, and grants) and summarized the trends in a report.

What are supercritical fluid, supercritical water, and subcritical fluid technologies? A supercritical fluid is a state of matter where both temperature and pressure are maintained above the "critical point." It loses the distinction between liquid and gas, possessing density close to a liquid and diffusivity/low viscosity close to a gas. The critical point for carbon dioxide (CO₂) is 31.1°C at 7.38 MPa, and for water, it is 374°C at 22.1 MPa.

Supercritical CO₂ is a clean solvent that reaches a supercritical state at relatively low temperature and pressure, already commercially established in food and pharmaceutical sectors for caffeine-free coffee production and hop aroma extraction. Supercritical water has powerful oxidation capacity and can completely detoxify persistent pollutants such as PFAS (perfluoroalkyl compounds). Subcritical water (approx. 150-374°C, high-pressure liquid water) is easier to handle due to milder conditions, utilized for extracting useful components from plants/waste and chemical resource recovery (chemical recycling) of biomass.

Meanwhile, in processes handling supercritical water, equipment corrosion under high-temperature and high-pressure conditions affects equipment lifespan. For supercritical CO₂ power generation, establishing materials for high-efficiency turbines and heat exchangers is key to commercialization, and technical challenges such as well drilling technology and corrosion-resistant materials remain for supercritical geothermal power generation.

In this report, we utilized Astamuse's proprietary database to analyze technological trends regarding "supercritical fluid, supercritical water, and subcritical fluid" in patents, academic papers, and grants. By grasping the evolution of keywords, it is possible to quantitatively evaluate technologies that have passed their peak popularity and those predicted to attract attention in the future.