Institute on Membrane Technology

This work presents the design of a membrane-integrated process for biogas valorisation and renewable hydrogen storage via CO 2 -to-methanol conversion. The process maximizes CO 2 utilisation by incorporating H 2 from renewable sources, while simultaneously separating methane from biogas to produce a stream suitable for direct injection into the natural gas grid. Membrane units are integrated upstream and downstream of the methanol synthesis reactor: upstream membranes allow to obtain a CO 2 -rich stream for methanol production and a CH 4 -rich stream compliant with grid specifications, while downstream membranes recover unreacted CO 2 and H 2 for recycling, minimizing emissions and hydrogen losses. The system is analysed in a step/stage configuration using performance maps from a validated one-dimensional model, accounting for the selectivity and permeance of a polyimide membrane. Results show that biogas can be fully valorised, achieving 98.5% CH 4 recovery with molar purity ≥97.5% and ∼97% CO 2 conversion to methanol, with nearly complete utilisation of renewable hydrogen. This membrane-integrated approach provides an effective strategy for coupling biogas upgrading with renewable hydrogen storage, enabling sustainable energy storage in the form of methanol e-fuels and contributing to carbon-neutral energy pathways. • High-efficiency membrane-assisted process enables full biogas valorisation and methanol synthesis. • Upstream separation achieves 98.5% CH 4 recovery at 98.7% purity for grid injection. • Downstream membranes maximize CO 2 and H 2 recycling, minimizing reactant losses. • CO 2 valorisation of 0.97 and nearly complete hydrogen utilisation. • Membrane-assisted design supports sustainable, carbon-neutral energy and hydrogen storage.

The study investigates the performance of polyethersulfone (PES) ultrafiltration (UF) membranes modified with a coating of polymerizable bicontinuous microemulsion (PBM) for membrane bioreactor (MBR) applications. Two types of PBM-modified PES membranes-casting-coated and spray-coated-were compared with a commercial PES membrane. A laboratory side-stream MBR (ssMBR) was employed to treat model wastewater (MW) with activated sludge under aerobic conditions. The fouling propensity of the membranes in ssMBR was evaluated through the implementation of two protocols: (i) flux-step test to treat low-strength domestic model wastewater (DMW) and (ii) constant flux test to treat high-strength olive mill model wastewater (OMW). The findings indicated that both the commercial PES and PBM spray-coated PES membranes started to critically foul at 36 L m-2 h-1. The PBM spray-coated membranes showed enhanced fouling resistance in comparison to the PBM casting-coated membranes. The deposition of the biofouling layer was the thinnest on PBM spray-coated membranes, which can be attributed to the low surface charge and high hydrophilicity of the modified membrane surface. In contrast, deposition of a thicker fouling layer was found on the commercial PES membrane, which can be attributed to the relatively higher surface charge promoting organic adsorption. A comparison of the fouling trends exhibited by commercial PES and PBM spray-coated membranes in OMW treatment revealed that they have similar fouling tendencies. However, a notable distinction emerged when the PBM spray-coated membrane was observed to demonstrate a lower fouling propensity accompanied by comparatively thinner fouling layers. The results demonstrate that the PBM spray-coated membranes have enhanced fouling resistance and filtration efficacy in MBRs treating wastewater with diverse strengths, thereby affirming their potential for application in wastewater treatment systems.

The present review aims to underline the inherent gas separation potential of pristine Pebax-1657, without any chemical modification, nor addition of filler material, by referring to a number of selected outstanding literature results. These results underscore the adequacy of pristine Pebax-1657 membranes in achieving excellent CO 2 gas separation performances, within or close to the target area of commercial applicability in terms of technoeconomic competitiveness when compared to alternative CO 2 separation/capture technologies. These achievements are facilitated by the utilization and combination of cutting-edge membrane preparation techniques. Additionally, the current review provides detailed information regarding material and gas separation properties based on experimental data, which are handpicked from literature and statistically presented to highlight significant differences in reported values. Basic empirical correlations emerging from these data are formulated, in order to provide a guideline for future membrane design, along with clarifications on important claims and points that are often encountered in relevant literature. • Details on structure and properties of pristine Pebax-1657 membranes • Experimental literature data on CO 2 gas separation with pristine Pebax-1657 membranes • Comparison of pristine Pebax-1657 membranes with other Pebax grade membranes • Experimental preparation techniques for top performing pristine Pebax-1657 membranes • Pristine Pebax-1657 membrane performance under various conditions and other gas pairs

The cover image is based on the article CytroCell@Nafion: Enhanced Proton Exchange Membranes by Mario Pagliaro etal., https://doi.org/10.1002/gch2.202500338.

Due to industrialization and globalization, water sources are increasingly contaminated with drugs. Among the various methods available, adsorption remains one of the most widely used techniques for drug removal. This work was to develop polysulfone (PSF) membranes integrated with montmorillonite (MMT) clay. The fabricated membranes were subsequently evaluated for their performance in removing diclofenac (DCF) from aqueous solutions. The membranes were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), contact angle measurements, as well as chemical and mechanical tests. Adding MMT at 1.5 and 2 wt% improved both hydrophilicity and mechanical strength. The natural hydrophilicity of MMT also accelerates the non-solvent/solvent exchange during phase inversion, resulting in higher porosity. These structural and surface modifications increased water permeability (16.36 L·m−2·h−1·bar−1), achieved 79% DCF removal, and enhanced antifouling properties. However, increasing the MMT clay content to 2.5 wt% caused particle aggregation, which reduced membrane performance. Fouling resistance tests with bovine serum albumin (BSA) as a model foulant showed a rejection rate of 89% and a flux recovery ratio (FRR) above 82% using an optimized membrane. These findings demonstrate that PSF/MMT membranes can serve as promising candidates for sustainable pharmaceutical wastewater treatment.

ABSTRACTWe investigate the use of lemon CytroCell nanocellulose as a new biobased filler for Nafion‐based proton exchange membranes. Pristine and composite membranes are prepared via casting and solvent evaporation technique. CytroCell is added up to 20 wt.% with respect to the polymer in a hydroalcoholic solution of Nafion perfluorosulfonic acid ionomer. Composite CytroCell@Nafion membranes are homogeneous on a molecular scale and showed enhanced proton conductivity with optimal performance for the composite membrane embedding 10 wt.% CytroCell. The composite membranes also showed improved flexibility and ductility compared to Nafion pristine membranes. Should stability of the new membranes be confirmed during prolonged PEM electrolyzer or H2 fuel cell operation, these findings open the route to the development of enhanced PEM membranes of broad applicability.

This work presents iTempDT, an AI-driven Digital Twin (DT) approach that uses deep learning to forecast indoor temperature based on Heating, Ventilation, and Air Conditioning (HVAC) system operations. Accurate temperature forecasting is essential for smart buildings (SBs), which aim to optimize energy efficiency without compromising occupant comfort. iTempDT addresses this need by providing accurate and timely forecasts that allow intelligent HVAC control and energy-efficient decision-making. At the core of iTempDT is a Temporal Convolutional Network (TCN) integrated with an attention mechanism to capture temporal dynamics and feature dependencies from multivariate time series data collected from both indoor and outdoor sensors. The model is trained for multi-step indoor temperature forecasting, explicitly conditioned on the recent HVAC status (ON/OFF), allowing for real-time predictions as well as scenario-based simulations. Also, an interactive dashboard enables real-time visualization and virtual control of HVAC settings. To promote sustainable and energy-conscious AI practices, iTempDT integrates a Green AI approach by applying post-training quantization. This reduces the model size and speeds up inference, making it suitable for deployment on low-power edge devices. The DT prototype was developed at the ICAR-CNR IoT Lab in Rende, Italy. iTempDT shows strong performance across key metrics (MAE, R<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, and RPD). Finally, the proposed approach is compared with other state-of-the-art models.