Driven by the continuous search to substitute fossil fuels, biomethane has gained significant relevance. However, its production requires biogas upgrading to remove siloxane compounds, notably hexamethyldisiloxane (L2). Adsorption is a cost-effective separation method for this application, with ordered mesoporous carbons (OMCs) proving to be highly effective adsorbents. This study proposes a methodology to predict L2 adsorption on a CMK-3 OMC at 298 K via molecular simulation, validating the results against experimental data. An OMC model was characterized using representative pore kernels (diameters of 20, 25, 30, 38, 45, and 55 Å) to simulate N₂ isotherms at 77 K and derive pore size distributions (PSDs). While the full six-pore kernel yielded the highest fit to experimental data (R² = 0.989), a reduced five-pore kernel (up to 45 Å pore) was defined as the optimal minimum kernel, achieving comparable accuracy (R² = 0.983) with one fewer pore. Local L2 isotherms at 298 K were subsequently simulated for these pores utilizing two literature-adapted force fields. Combining these local isotherms with the N₂ PSDs enabled the prediction of total L2 isotherms, where the highest predictive accuracy (R² = 0.88) was achieved using the kernel restricted to 45 Å. Finally, simulations of conventional materials, granular activated carbon (GAC) and activated carbon fiber (ACF), successfully reproduced the experimentally observed adsorption capacity hierarchy (OMC > GAC > ACF).
Control over the particle size of precipitated calcium carbonate (PCC) based on a liquid–liquid process is a critical factor influencing the production of nanoparticles (NPs) with uniform particle size. In this study, we present an innovative size-selective method for the synthesis of PCC NPs from industrial calcium-rich waste in a bench-scale unit. The proposed method is based on the membrane emulsification technique to produce double emulsions (DEs) with optimized droplet size distribution. A novel membrane, involving a porous organic polymer functionalized with a hybrid of polyurethane—melamine and polyethersulfone, was developed as the separation layer. The droplet size distribution of the DEs was analyzed using droplet light scattering. The effects of the internal aqueous phase to organic phase (W1/O) volume ratio, as well as the concentrations of Ca2⁺ and non-ionic surfactants (Span 80 and Tween 80), on the droplet size of DEs were studied before and after filtration. Under optimized conditions (W1/O ratio: 8:1, Ca2⁺ 1.2 M, and surfactant concentration: 1.2 mM), the lowest mean droplet size of 24.6 µm was obtained, together with a narrow size distribution, indicating enhanced DE stability. The porous nature of the hydrophobic membrane provides a uniform size distribution of droplets. The proposed membrane achieved a maximum permeate flux of 715 L m−2 h−1 at a W1/O ratio of 12:1 and a filtration efficiency of 95.3
The conventional food processing techniques although widely employed have certain drawbacks they degrade the nutrients, produce a great quantity of waste and have a greater expenditure of energy. Process intensification (PI) an engineering approach aimed at making equipment and operations smaller, cleaner and more energy and mass transfer efficient offers a route to address these limitations but the present food-technology literature commonly conflates PI with novel non-thermal preservation more broadly. This review addresses that gap by classifying nine technologies into two mechanistically distinct families reactor/structure intensification (microreactors, oscillatory flow reactors) and emerging processing technologies (high-pressure processing, pulsed electric field, supercritical fluid extraction, cold plasma, ultrasound, pulsed light, microwave) that intensify heat or mass transfer within a specific unit operation. Each have been summarized for operating principles, representative food applications and reported performance and evaluated the technologies against recurring barriers to industrial adoption inconsistent reporting of energy and sustainability metrics, scarce techno-economic and life-cycle assessment (TEA/LCA) data and uneven regulatory status. By consolidating this evidence into a single comparative frame the review clarifies which technologies are ready for scale-up and identifies the quantitative rather than qualitative evidence still needed to support their industrial adoption. Nine technologies are classified into reactor/structure intensification and mass-/energy-transfer intensification families based on Stankiewicz and Moulijn’s engineering definition of process intensification. Microreactors and oscillatory flow reactors achieve encapsulation, crystallization, and extraction outcomes unattainable with conventional stirred-tank equipment. HPP, PEF, SFE, cold plasma, ultrasound, pulsed light and microwave preserve nutrients and safety, but report energy and efficacy data on inconsistent bases; PEF’s 1–10 kJ/kg for effective microbial inactivation is one of the few figures reported on a standardized specific-energy basis. Quantitative TEA and LCA evidence remains scarce across all nine technologies, limiting evidence-based sustainability comparison. Industrial adoption is constrained by scale-up economics, regulatory inconsistency, and uncharacterized transformation-product safety.
Citrus residues, particularly lemon peel, pose significant environmental challenges due to disposal difficulties. Despite this, they represent an abundant biomass resource with high recovery potential. One promising valorization route is their use for biohydrogen production via dark fermentation. However, their complex structure and the presence of inhibitory compounds can limit biological conversion. This study evaluated the effect of fungal hydrolysis as a pretreatment for dark fermentation of lemon peel, using strains of Colletotrichum gloeosporioides, Phytophthora sp., Fusarium oxysporum, and Alternaria alternata, and assessed its impact on hydrogen production. The results showed that fungal pretreatment promoted carbohydrate solubilization, with A. alternata demonstrating the highest capacity for releasing soluble carbohydrates, and the presence of phenolic compounds had a minimal effect. Subsequent dark fermentation of pretreated substrates resulted in significant increases in hydrogen production of 69
This study investigated the effect of niobium (Nb) surface modification of biochar via magnetron sputtering on the adsorption of ivermectin and diclofenac potassium, using an integrated approach combining equilibrium experiments and statistical physics-based adsorption models. The biochar was obtained by pyrolysis and then coated with Nb for 30 min at 150 W DC power. We analyzed adsorption equilibrium data using advanced isotherm models to evaluate the process’s steric and energetic parameters. The results indicated predominantly physisorption, with adsorption energies of 17–19 kJ mol− 1 for ivermectin and approximately 11 kJ mol− 1 for diclofenac. Steric parameters exceeded 1 for both drugs, suggesting multi-molecular adsorption, while modeling indicated the formation of two layers on the material’s surface. For ivermectin, maximum adsorption capacities ranged from 81 to 111 mg g− 1. Furthermore, increasing temperature enhanced ivermectin’s affinity for the modified biochar, whereas diclofenac showed the opposite behavior, highlighting distinct adsorption responses between the two contaminants. Based on the modeling parameters and the adsorbent’s physicochemical characteristics, the results suggest that ivermectin adsorption may involve dipole–dipole interactions, hydrogen bonding, and π–π interactions, while diclofenac adsorption may involve electrostatic interactions, hydrogen bonding, and π–π interactions. These results show that Nb surface modification distinctly influences the adsorption behavior of the two drugs and highlight the potential of magnetron sputtering as a surface-engineering strategy for developing biochars with differential affinity for pharmaceutical contaminants.
