A confined-fluidized bed was investigated as a dynamic adsorber-regenerator for CO2 capture using amino-functionalized mesoporous silica (APTES20). Adsorption, gas switching, in situ temperature-swing desorption and cooling were repeated in the same reactor without sorbent transfer. In one 68-cycle series, the fitted adsorption-capacity trend decreased by approximately 1.5%; individual-cycle scatter and the absence of independent replicate series limit inference about long-term material lifetime. The results demonstrate cyclic operation over the tested window, not industrial-scale durability.
This study develops an integrated chemical-technological framework for aerosol gas mixtures through combined control of propellant quality, solvent moisture, corrosion risk, and regenerated-solvent suitability. The methodology couples input quality control of gas propellants and organic solvents with multi-parameter testing of filled products (formulation, heat of combustion, vapor pressure at 20 and 50 °C, leak tightness, release rate, ignition distance, and foam ignition). Three products were examined: aerosol penetrating lubricant (APL), aerosol surface cleaner (ASC), and aerosol hair foam (AHF), representing hydrocarbon-rich, solvent–water, and water-dominant systems. Product behavior depended on the balance of propellant fraction, liquid-phase composition, and moisture-sensitive components. APL (highest fraction 0.600; 45.87 kJ/g; 2.1 g/s) ignited at 600–900 mm and was classified as extremely flammable. ASC (0.340; 26.08 kJ/g; 1.3 g/s) ignited only at 150–300 mm, corresponding to a flammable aerosol. AHF was not found to be flammable under the conditions stated above. The pressure, reserve and no leakage were observed in all products. The primary set of cross-cutting risks were moisture, which led to corrosion, contaminating valves, pressure drop, and instability. The method presents a methodology that connects raw material control, filled product analysis, corrosion analysis, and reclaimed solvent verification, and provides a comprehensive pathway to ensure that the aerosol user obtains the desired quality and a safe product.
Ecological restoration of waste slag sites is often constrained by topsoil scarcity and nutrient deficiency. Therefore, this study investigated organic acid-matured granite rock powder (M-GRP) to evaluate its mineral nutrient-release behavior and structural evolution, with the aim of developing it as a compost mineral additive. The results showed that 0.2 mol/L malonic acid, a solid-to-liquid ratio of 1:75, and maturation at room temperature for 8 h provided effective nutrient release from granite rock powder. Characterization analysis showed that protons and organic groups in malonic acid promoted the dissolution of feldspar and illite in granite rock powder, accompanied by the substantial dissolution of clinochlore and calcite. Feldspar and illite exhibited severe dissolution at edges and protrusions, forming pits and pores. Malonic acid treatment decreased the unit-cell volume and interplanar spacing of the surviving mineral phases and interplanar spacing, and increased surface roughness, lattice defects, and surface disorder. Quartz remained comparatively stable, with its morphology and crystal structure preserved. In addition, the specific surface area of M-GRP increased, accompanied by changes in its pore structure and pore-size distribution. These results provide a theoretical basis and technical support for the resource utilization of rock powder.
Temporary CO2 storage is gaining interest for applications requiring compact storage at moderate pressures, where the low volumetric density of gaseous CO2 limits storage capacity without high-pressure compression. Adsorption in porous materials offers a potential means of increasing storage density, although tank-scale studies remain scarce. This work experimentally and numerically investigated adsorption-based CO2 storage using a 17 L tank containing 6 kg of coconut shell activated carbon over a 1–10 bar charge–dormancy–discharge sequence. Experimental measurements of the CO2 mass flow rate, pressure, and temperature were used to calibrate a lumped-parameter dynamic model that can be integrated into system-level simulations. The activated carbon increased the volumetric storage capacity compared with an empty tank, with deliverable storage enhancement factors between 4 and 8 depending on the discharge conditions. Heat exchange with the atmosphere during charging and discharging had only a minor influence, while cooling during dormancy reduced the recoverable working capacity. Compared with isothermal operation, the working capacity decreased by approximately 35% under adiabatic conditions, with an additional 37% reduction when heat exchange with the surroundings was included, highlighting the importance of limiting heat losses during storage. These findings highlight the potential of adsorption as a strategy for temporary CO2 storage.
Per- and polyfluoroalkyl substances (PFASs) are persistent contaminants detected in groundwater at closed municipal landfills in rural Minnesota, where legacy waste continues to release PFASs decades after closure. In this setting, contaminated groundwater used for irrigation creates a direct pathway for PFAS transfer into the food supply. This study evaluates remediation at the groundwater–irrigation interface through a unified techno-economic assessment comparing granular activated carbon (GAC) adsorption and phytoremediation with Festuca rubra (F. rubra). Design influent concentrations were set at the 90th percentile (P90) of five representative PFASs measured in rural Minnesota landfill groundwater. Adsorption was simulated using a pore and surface diffusion model for single-bed and lead–lag configurations under fouling and non-fouling conditions. Phytoremediation was modeled using three complementary scenarios: a greenhouse-derived upper bound, a bioconcentration factor (BCF)-derived mechanistic case, and a decomposed scaling formulation. Unit costs were anchored to Minnesota Pollution Control Agency 2023 guidance and University of Minnesota (UMN) Extension data. Adsorption achieved compliance within weeks at $5.24–$8.00 m−3; phytoremediation showed lower per-volume cost ($0.43 m−3) but required centuries to multi-millennial timescales for long-chain PFASs. Cumulative cost was dominated by treatment duration rather than per-volume intensity, with adsorption more cost-effective when compliance timeframes are constrained. These findings highlight that remediation feasibility depends on alignment between treatment timescale and risk-management objectives rather than levelized cost alone.
