Supercritical Technology Applied to Food, Pharmaceutical, Chemical and Energy Industries—2nd Edition

The unique dual properties of supercritical fluids—the dissolving power of liquids combined with the low viscosity and high diffusivity of gases—make these substances attractive for a wide range of applications, including the extraction of solid materials, fractionation of substances, sterilization, and power generation. The term “supercritical technology” addresses processes that operate under conditions near to or above the critical point of the solvent of interest [1,2].

As a continuation of the previously published Special Issue, “Supercritical Technology Applied to Food, Pharmaceutical and Chemical Industries” (available online: https://www.mdpi.com/journal/processes/special_issues/Supercritical_Technology. Accessed on 30 August 2026), this Special Issue “Supercritical Technology Applied to Food, Pharmaceutical, Chemical and Energy Industries—2nd Edition” expands the scope of applications considered within the field of supercritical fluids. While supercritical-fluid extraction has become one of the most investigated industrial applications of supercritical technology, its potential in energy-related processes, including power generation, remains comparatively less explored and recognized. By bringing together contributions spanning food, pharmaceutical, chemical, and energy applications, this Special Issue seeks to provide a broader perspective on the current research scenario involving supercritical fluids in industrial processes.

Along with the application of supercritical fluids in extraction processes, either as a method for obtaining high-value extracts or as a methodology to prepare samples prior to analytical detection, this Special Issue addresses several additional processes that are worthy of investigation. For example, one study investigated particle formation through the explosive boiling of an ibuprofen solution in subcritical carbon dioxide. Another study employed molecular dynamics simulations to examine the phase behavior of CO₂ over a range of temperatures and pressures, providing valuable insights for industrial processes such as carbon capture and storage.

In the field of power generation based on supercritical technology, a detailed evaluation of temperature distributions in 1000 MW ultra-supercritical pulverized coal boilers was performed. In addition, the salt-precipitation deposits generated during supercritical water gasification were investigated, and potential strategies for process optimization were proposed.

Finally, the current state of supercritical-fluid technology-based processes in the agri-food, chemical and energy sectors was reviewed, with particular emphasis on future directions. These include the use of supercritical fluids for the recovery of metals from spent catalysts and the application of supercritical carbon dioxide in combination with nuclear waste to convert biomass-derived energy into heat and electricity.

The studies published in this Special Issue bridge knowledge gaps in well-established applications, such as supercritical-fluid extraction and particle formation, while highlighting recent developments in the use of supercritical fluids in less common applications, such as power generation. As with any emerging technology, supercritical-fluid-based technologies should be accompanied by a broader assessment of their environmental performance and economic evaluation [3]. Although these processes may offer greater efficiency than conventional alternatives, their classification as “clean” should not be based solely on the use of solvents that replace petroleum-based chemicals. Energy consumption associated with maintaining high pressure and temperature, the use of solvents from biogenic sources, and overall process efficiency must also be considered when evaluating their environmental footprint [4].

A responsible economic evaluation of supercritical-fluid-based processes should consider different scenarios, including product demand, geographical location, local fees, regulations, quality requirements, and other relevant factors. Such a comprehensive assessment can provide a realistic representation of these processes for different stakeholders.

In this context, it is expected that the topics covered in this Special Issue will contribute to the technological development and extended industrial adoption and commercialization of supercritical-fluid-based processes.