Hollow Fiber Membrane Module Research Articles

Influence of irregular fiber filling on the performance of hollow fiber membrane modules for cold water production

The countercurrent hollow fiber membrane-based evaporative water cooler (MEWC) offers an eco-friendly and compact solution for cold water generation. This study introduces a random sequential addition algorithm to model the real-world irregular fiber filling within the MEWC. Inspired by the honeycomb structure, the developed 3-D numerical model adopts a calculation unit featuring a hexagonal prism comprising multiple fibers. Validation against experimental data reveals an average relative error of 2.81 % concerning outlet water temperature. The effects of fiber filling patterns (regular layout and random layout) on the velocity and temperature fields of the MEWC are investigated. Comparisons of outlet water temperature, cooling efficiency, consumptive electric power ratio, and heat and mass transfer resistance composition between these layouts under various operating conditions are conducted. The results indicate that the random layout fosters severe channeling effect and large flow dead zones, impairing air side heat and moisture transfer. The random layout exhibits over 15.9 % reduction in cooling efficiency and 36.3 % decrease in consumptive electric power ratio compared to the regular layout. Irregular fiber filling leads to a notable 158.6 % increase in air side heat transfer resistance and a 35.9 % rise in mass transfer resistance. Although irregular filling compromises the cooling performance, it demonstrates potential for energy savings under certain conditions. Design schemes should be carefully tailored to meet specific application requirements by considering these trade-offs.

Three-dimensional CFD modeling for hollow fiber gas separation membrane modules based on a dual porous media model

Mathematical modeling is crucial to optimizing the design of the hollow fiber membrane (HFM) module. A Computational Fluid Dynamics (CFD) model enables efficient three-dimensional (3D) simulations of HFM modules, which integrates a dual porous media approach, significantly reducing computational costs. Validation against alternative simulations and experimental data confirms its prediction capability (<7% deviation). Comparative analyses demonstrate the superior reliability of the 3D approach over one-dimensional simulations. Detailed velocity, pressure, and concentration profiles for the shell and tube sides reveal optimization opportunities such as dead zones within the module. Aerometric studies show significant pressure drops (>30%) for smaller fiber diameters (<100μm) on the permeate side. The model's adaptability suggests broader applications in membrane gas separation processes with modifications. This research highlights the efficacy of CFD modeling in enhancing the design and optimization of HFM modules, highlighting the cost savings of the dual porous media approximation.

Mass transfer of bilirubin and bovine serum albumin in hollow fiber membrane module of artificial liver

Understanding the mass transfer behaviors in hollow fiber membrane module of artificial liver is important for improving toxin removal efficiency. A three-dimensional numerical model was established to study the mass transfer of small molecule bilirubin and macromolecule bovine serum albumin (BSA) in the hollow fiber membrane module. Effects of tube-side flow rate, shell-side flow rate, and hollow fiber length on the mass transfer of bilirubin and BSA were discussed. The simulation results showed that the clearance of bilirubin was significantly affected by both convective and diffusive solute transport, while the clearance of macromolecule BSA was dominated by convective solute transport. The clearance rates of bilirubin and BSA increasd with the increase of tube-side flow rate and hollow fiber length. With the increase of shell-side flow rate, the clearance rate of bilirubin first rose rapidly, then slowly rose to an asymptotic value, while the clearance rate of BSA gradually decreased. The results can provide help for designing structures of hollow fiber membrane module and operation parameters of clinical treatment.

Jet-assisted membrane filtration and design application: A model for fouling removal area estimation

Membrane fouling remains a significant challenge in desalination and other membrane-based filtration processes. This study presents a novel force-balance model to accurately estimate the de-fouling area in jet-assisted filtration for in-situ fouling control. The model includes various design parameters, such as initial jet velocity, nozzle diameter, impinging angle, membrane pore size, membrane resistance, and permeate flux. The validation showed a strong correlation between theoretical predictions and experimental observations, with an R2 value of 0.97, indicating high predictive accuracy. Additionally, an empirical formula and design automation tools were developed to facilitate the configuration of jet filtration modules, enabling practical application of the findings. As a demonstration, the arrangement of multiple jets in a hollow fiber membrane module was optimized using the model, significantly improving microalgae filtration performance. The optimized jet configuration enhanced permeate flux by 236 % and reduced the specific energy consumption by 67 % compared to conventional setups. This research offers a framework for extending the application of jet-based fouling mitigation and cleaning in various membrane filtration systems, providing substantial improvements in efficiency and operational sustainability.

Effect of the main properties of membrane materials on denitrification of hydrogen-based membrane biofilm reactors (H2-MBfRs)

Hydrogen-based membrane biofilm reactors using hollow-fiber membrane modules as their functional cores can play an important role in treating oxidizing pollutants. However, most studies have focused on pollutant removal, and few have investigated how membrane material properties affect reactor's operation. Here, we selected polyvinyl chloride (PVC) and polyvinylidene fluoride (PVDF) hollow fiber membrane materials with large differences in membrane surface properties to assemble the reactor, and investigated how the membrane properties affected nitrate removal and EPS secretion in MBfRs. The results showed that the membrane surface zeta potential and membrane contact angle had a certain positive impact on the NO3−-N removal rate and total EPS secretion in the MBfRs. When the contact angle (74.51–85.51°) and zeta potential (−12.5–4.5) increased, the biofilm on the membrane surface secreted more binding proteins (90.81–113.54 mg/gVSS), facilitating reactor biofilm growth, pollutant removal, and impact loads. Moreover, the properties of the experimentally selected PVC membrane material are more suitable for MBfR operation and are in line with the fundamental need for energy saving and emission reduction in modern society. This study provides a theoretical basis for the selection of membrane materials to enhance denitrification in H2-MBfRs, and an engineering foundation for reactors applications.

Integration of two-stage membrane distillation and fenton-based process for landfill leachate treatment: Ammonia and water recovery and advancement towards zero liquid discharge

The recovery of resources from landfill leachate (LL) represents a more sustainable approach, as it combines meeting release standards with the valorization of raw materials and contributing to the circular economy. Therefore, this study aims to evaluate the performance of a two-stage Direct Contact Membrane Distillation (2S-DCMD) for the recovery of water and ammonia from LFL integrated with the Fenton-based process for the treatment of the membrane concentrate generated in the second stage, aiming to obtain zero effluent discharge. In the first stage, the hot LFL flows through the shell side of the polypropylene hollow fiber membrane module, while the sulfuric acid solution passes through the lumen side·NH3 is recovered in the form of ammonium sulfate. In the second stage, the hot effluent from the first stage flows through the hot channel of the poly(tetrafluoroethylene) sheet membrane module, while the cooled distilled water flows through the other side in countercurrent. Despite the high efficiency of MD, disposing of the concentrate presents challenges, as pollutant concentrations can escalate by an additional 25 % to 50 % compared to the original contaminants in the raw feed. To address this issue, an advanced oxidative process of Fenton (AOP/Fenton) was optimized for treating the concentrate. In the first stage, NH3 removal reached 97.84 %, accompanied by a recovery rate of 79 %. In the second stage, a permeate with high quality was produced. Substantial removal rates were observed in this stage: colour (99.96 %), turbidity (99.89 %), COD (99.33 %), and Sulfates (90.08 %). The AOP/Fenton under optimal conditions (21.50 g/L of Fe2+ and 80 mL of H2O2) the removal of COD was 88.69 %. Thus, this route emerges as a viable alternative for landfill leachate treatment with the recovery of important resources.

In-situ enforcing molecular diffusion to functionalize hollow fiber carbon membranes enables efficient CO2 separations

Microporous carbon membranes with tunable micropores are attractive materials for CO2 separations. Tailoring the gas transport channels is an effective strategy to achieve high separation performance, while it remains challenging due to the lack of control over sub-nanopores. Herein, we present an in-situ molecular functionalization strategy wherein the confined sub-nanopore properties are designed by enforcing molecules to diffuse over pores and functionalize the pore affinity. By enforcing oxygen-functionalization, a strong CO2 affinity between the carbon matrix and CO2 molecules is generated, which facilitated CO2 transport, thereby enhancing the CO2 permeability by ∼4.7-fold and without sacrificing molecular sieving ability for gas mixtures, like CO2/N2 and CO2/CH4. The functionalization mechanism was confirmed using reactive force field molecular dynamics (ReaxFF-MD) simulations. Furthermore, this strategy, which was directly applied to hollow fiber membrane modules, provides a facile and scalable approach, and expands the currently limited library of penetrative micropore tailoring of microporous membranes.

Extracellular vesicles selective capture by peptide-functionalized hollow fiber membranes

Recently, membrane devices and processes have been applied for the separation and concentration of subcellular components such as extracellular vesicles (EVs), which play a diagnostic and therapeutic role in many pathological conditions. However, the separation and isolation of specific EV populations from other components found in biological fluids is still challenging. Here, we developed a peptide-functionalized hollow fiber (HF) membrane module to achieve the separation and enrichment of highly pure EVs derived from the culture media of human cardiac progenitor cells. The strategy is based on the functionalization of PSf HF membrane module with BPt, a peptide sequence able to bind nanovesicles characterized by highly curved membranes. HF membranes were modified by a nanometric coating with a copoly azide polymer to limit non-specific interactions and to enable the conjugation with peptide ligand by click chemistry reaction. The BPt-functionalized module was integrated into a TFF process to facilitate the design, rationalization, and optimization of EV isolation. This integration combined size-based transport of species with specific membrane sensing ligands. The TFF integrated BPt-functionalized membrane module demonstrated the ability to selectively capture EVs with diameter < 200 nm into the lumen of fibers while effectively removing contaminants such as albumin. The captured and released EVs contain the common markers including CD63, CD81, CD9 and syntenin-1. Moreover, they maintained a round shape morphology and structural integrity highlighting that this approach enables EVs concentration and purification with low shear stress. Additionally, it achieved the removal of contaminants such as albumin with high reliability and reproducibility, reaching a removal of 93%.

Progress in module design for membrane distillation

There have been tremendous advances in membrane distillation (MD) since the concept was introduced in 1961: new membrane designs and process configurations have emerged, and its commercial viability has been evaluated in several pilot-scale studies. However, its high energy consumption has hindered its commercialization. One of the most promising ways to overcome this obstacle is to develop more energy-efficient membrane modules. The MD research community has therefore developed diverse new module configurations for hollow fiber and flat sheet membranes that increase the thermal energy efficiency of MD by minimizing thermal polarization, increasing mass transfer across the membrane, and improving heat recovery from the condensed vapor. This review summarizes the progress made in the design of hollow fiber and flat sheet membrane modules for MD applications. It begins with a brief introduction to MD and its configurations before describing developments in module fabrication and highlighting key areas where further research is needed.

Wall-mounted ultrafine hollow fiber membrane module for purification of domestic surface water

The World Health Organization (WHO) estimated that around 844 million people worldwide lack safe drinking water, including 159 million who are dependent only on surface water. Investing in a practical, sustainable, and cost-effective treatment process is indispensable to alleviating the effect of water shortage. Besides water treatment, ultrafiltration (UF) membranes are broadly used in protein fractionation and clarification of fruit juices. The hollow fiber (HF) membrane configuration has a much larger surface area per unit volume, resulting in higher productivity than the flat-sheet membrane. A spinneret was developed with a provision for altering the fiber's inner diameter from 1000 µm to 150 µm and outer dimension from 1500 µm to 350 µm, respectively, using an inbuilt detachable needle arrangement. The ultrathin hollow fiber produced by the indigenously designed spinnerets has a high surface area and packing density, which makes it useful for surface water treatment. A wall-mounted module was designed for direct connection to the tap to obtain a purified water flow of 30–40 liter per hour (LPH) for domestic use, operated with or without electricity. The fabricated ultrafine HF module (ID: 150–200 µm; OD: 350–450 µm) removes complete bacterial contamination and turbidity up to 95–100 %, making the quality of processed water potable. The developed membrane module is durable due to its large membrane area per unit volume, enhancing productivity, high packing density, good fouling resistance, easy handling, and self-supporting structure for backwashing. The present research article paves the way forward to investing in a practical, sustainable, and economical treatment process that is indispensable to alleviating the effect of water shortage.

Process Operability Analysis of Membrane-Based Direct Air Capture for Low-Purity CO2 Production.

Addressing climate change constitutes one of the major scientific challenges of this century, and it is widely acknowledged that anthropogenic CO2 emissions largely contribute to this issue. To achieve the "net-zero" target and keep the rise in global average temperature below 1.5 °C, negative emission technologies must be developed and deployed at a large scale. This study investigates the feasibility of using membranes as direct air capture (DAC) technology to extract CO2 from atmospheric air to produce low-purity CO2. In this work, a two-stage hollow fiber membrane module process is designed and modeled using the AVEVA Process Simulation platform to produce a low-purity (≈5%) CO2 permeate stream. Such low-purity CO2 streams could have several possible applications such as algae growth, catalytic oxidation, and enhanced oil recovery. An operability analysis is performed by mapping a feasible range of input parameters, which include membrane surface area and membrane performance metrics, to an output set, which consists of CO2 purity, recovery, and net energy consumption. The base case for this simulation study is generated considering a facilitated transport membrane with high CO2/N2 separation performance (CO2 permeance = 2100 GPU and CO2/N2 selectivity = 1100), when tested under DAC conditions. With a constant membrane area, both membranes' intrinsic performances are found to have a considerable impact on the purity, recovery, and energy consumption. The area of the first module plays a dominant role in determining the recovery, purity, and energy demands, and in fact, increasing the area of the second membrane has a negative impact on the overall energy consumption, without improving the overall purities. The CO2 capture capacity of DAC units is important for implementation and scale-up. In this context, the performed analysis showed that the m-DAC process could be appropriate as a small-capacity system (0.1-1 Mt/year of air), with reasonable recoveries and overall purity. Finally, a preliminary CO2 emissions analysis is carried out for the membrane-based DAC process, which leads to the conclusion that the overall energy grid must be powered by renewable sources for the technology to qualify within the negative emissions category.

Numerical Simulation of Mass Transfer in Hollow Fiber Membrane Module for Membrane-Based Artificial Organs.

The mass transfer behavior in a hollow fiber membrane module of membrane-based artificial organs (such as artificial liver or artificial kidney) were studied by numerical simulation. A new computational fluid dynamics (CFD) method coupled with K-K equation and the tortuous capillary pore diffusion model (TCPDM) was proposed for the simulations. The urea clearance rate predicted by the use of the numerical model agrees well with the experimental data, which verifies the validity of our numerical model. The distributions of concentration, pressure, and velocity in the hollow fiber membrane module were obtained to analyze the mass transfer behaviors of bilirubin and bovine serum albumin (BSA), and the effects of tube-side flow rate, shell-side flow rate, and fiber tube length on the bilirubin or BSA clearance rate were studied. The results show that the solute transport mainly occurred in the near inlet regions in the hollow fiber membrane module. Increasing the tube-side flow rate and the fiber tube length can effectively enhance the solute clearance rate, while the shell-side flow rate has less influence on the BSA clearance. The clearance of macromolecule BSA is dominated by convective solute transport, while the clearance of small molecule bilirubin is significantly affected by both convective and diffusive solute transport.

Optimization of nitrogen removal and microbial mechanism of a hydrogen-based membrane biofilm reactor

ABSTRACT The hydrogen-based membrane biofilm reactor (H2-MBfR) is an emerging biological nitrogen removal technology characterized by high efficiency, energy-saving capability, and environmental friendliness. The technology achieves denitrification and denitrogenation of microorganisms by passing hydrogen as an electron donor from inside to outside through the hollow fibre membrane module, and eventually the hydrogen reachs the biofilm attached to the surface of the fibre membrane. H2-MBfR has obtained favourable outcomes in the treatment of secondary biochemical effluent and low concentration nitrogen polluted water source. The experiment was optimized by s single-factor testing and response surface methodology-based optimization (RSM), and the optimal operational conditions were obtained as follows: an influent flow rate of 2 mL/min, hydrogen pressure of 0.04 MPa, and influent nitrate concentration of 24.29 mg/L. Under these conditions, a high nitrate removal rate of 98.25% was achieved. In addition, Proteobacteria and Bacteroidetes were the dominant bacteria in all stages, and the genus Hydrogenophaga was sufficiently enriched, occurring at 13.0%–49.0% throughout the reactor operation. Furthermore, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway for nitrate reduction and inorganic carbon utilization by microorganisms in the H2-MBfR was explored through comparison with the KEGG database. The results provided a mechanistic explanation for the denitrification and carbon sequestration capacity of the H2-MBfR.

Effect of Oxidants in the Utilization of Polysulfone Hollow Fiber Membrane Module as Bubble Reactor for Simultaneously Removal of NOx and SO2

Effect of Oxidants in the Utilization of Polysulfone Hollow Fiber Membrane Module as Bubble Reactor for Simultaneously Removal of NOx and SO2

Polymeric hollow fiber membrane for cooling crystallization seeding: On the mechanism of induced nucleation based on thermal transfer

Cooling crystallization is an important separation process and particuology technology that requires accurate nucleation control strategies. Herein, we introduced the polymeric hollow fiber membrane with proper thermal properties as the effective nucleation induction interface during cooling crystallization. The heterogeneous nucleation control mechanism was introduced based on classical nucleation theory and the thermal transfer process. Interfacial properties and the thermal conductivity of two kinds of polymeric membranes, polytetrafluoroethylene (PTFE) and polyethersulfone (PES), were measured and simulated with the developed model. These two membranes possessed different nucleation induction periods, nucleation rates and crystallization performances, which validated that the hollow fiber membrane module could effectively accelerate the nucleation process compared to conventional cooling crystallization owing to the shorter nucleation induction period and the reduced solution surface tension. Due to the higher hydrophobicity and the lower roughness of the membrane surface, the PTFE membrane possessed a more moderate performance in generating stable heterogeneous nucleation than the one of PES membrane. Thus, the adjustable membrane property enabled the hollow fiber membrane-assisted cooling crystallization to possess the accurate nucleation control and desired terminal particle products.

Slippery hydrogel surface on PTFE hollow fiber membranes for sustainable emulsion separation.

Establishing an efficient and sustainable membrane module is of great significance for practical oil/water emulsion separation. Superwetting membranes have been extensively studied but cannot meet long lasting separation owing to inevitable membrane fouling. Herein, we constructed a hydrogel-mediated slippery surface on polytetrafluoroethylene (PTFE) hollow fibers and then designed a flexible and swing hollow fiber membrane module inspired by fish gill respiration, which achieved sustainable emulsion separation. A vinyl silane-crosslinked polyvinylpyrrolidone (PVP) hydrogel was interpenetrated with nano-fibrils of the PTFE hollow fibers, thus facilitating fast water permeance while resisting oil intrusion. Liquid-like polydimethylsiloxane (PDMS) brushes were then grafted to promote oil aggregation-release from the membrane surface. Owing to the heterogeneous surface and gill-like structure, the designed PTFE hollow fiber membrane module could separate emulsion in a long-term filtration process, maintaining a high water permeability of 500 L m-2 h-1 bar-1 with a separation efficiency of over 99.9% for 5000 min. This novel technique shows its great potential to realize practical emulsion separation by solving the persistent problem of membrane fouling and permeance decay.

Spontaneous dark fermentation in a pre-seeded liquid-gas membrane bioreactor: Impact of wine and coffee biowaste microflora on continuous biohydrogen production

One of the challenges of continuous bioproduction of hydrogen by dark fermentation is to extract the gases produced and efficiently maintain the active bacterial consortium in the bioreactor. In this study, the process of hydrogen production was intensified by coupling dark fermentation to in situ gas extraction using a hollow fiber membrane module working as liquid-gas contactor. The value of this continuous liquid-gas membrane bioreactor (L/G MBR) was previously proved with a model substrate and the stabilization of a bacterial consortium deposited on the fibers. This work in an original way attempts to answer the question of the impact of feeding the bioreactor with unhygienized biomass having its own bacterial microflora capable of producing hydrogen. A new L/G MBR was inoculated with digestate from endogeneous dark fermentation of grape must deposits, mainly composed of hydrogen-producing bacteria. It was subsequently operated as a continuous liquid-gas membrane bioreactor (L/G MBR) without additional bacterial seeding, using different biomasses. The feasibility of spontaneous biohydrogen production in the L/G MBR was demonstrated for several organic byproducts originated from agriculture or the food industry (grape must deposits (same biomass for feeding), grape pomace, and coffee silverskin), chosen for their potential to ensure year-round availability. Production performances of 0.9–4.1 L H2/L/d and 18–86 LH2/kgCOD were obtained from the different waste liquid fractions. The bacterial and metabolic profiles of biomass digestates, produced by endogenous fermentation in a semi-batch bioreactor or by spontaneous fermentation in the L/G MBR were compared and showed that the bacterial consortium found in the digestate was linked either to the biomass’ indigenous flora or to the L/G MBR seeding. Thus, H2 production from coffee silverskin (a biomass that did not impose its own microflora) could be enhanced by seeding the L/G MBR with selected bacteria, implanted in the bioreactor. This offers exciting perspectives for the further development of efficient low-tech processes for producing biohydrogen from biomass.

Application of an electrochemical filter-press flowcell in an electrocoagulation-MBR system: Efficient membrane fouling mitigation

In this study, we present efficient fouling mitigation of a pre-pilot Membrane Bio Reactor (MBR) for the treatment of synthetic wastewater through real integration with the Electrochemical Coagulation (EC) process by the application of a satellite filter-press electrochemical flowcell at the recirculation line of permeate produced by submerged hollow fiber membrane module. Flowcell was equipped with an aluminum anode and a steel cathode. Results indicated that the application of 5 volts was the optimum level for an EC-MBR for the removal of COD and fouling mitigation. 5 V-EC led to ca. 80 ± 3% COD removal, while MBR and 5 V-EC-MBR achieved almost 63 ± 4 and > 99% COD removal after 6 hr HRT, respectively. Moreover, the optimum 5 V-EC-MBR extended the membrane operational time by ca. 35 days in comparison with MBR. The formation of large microorganism flocs/more porous sludge cake layer along with the entrapment of Extracellular Polymeric Substances (EPS), were found as major mechanisms influencing the fouling mitigation. Dynamic Light Scattering (DLS) resulted in mean particle size (MPS)/zeta potential (ZP) values of − 5 ± 2.3/89 and − 60 ± 3/12 µm/mV for mixed liquor sludge flocs of 5 V-EC-MBR and MBR respectively, while colloidal re-stabilization (change in the sign of ZP and reduced MPS) was observed when applying larger voltages than 5 V. The presence and the reduction of EPS were verified using Fourier Transform InfraRed (FTIR) and fluorescence Emission Excitation Matrix (EEM). The results of this study pave the way for future techno-economic evaluations of continuous pilot EC-MBR equipped with multiple electrochemical flowcells for the treatment of real wastewater.

PVDF hydrophobic hollow fiber membrane modules for partial dealcoholization of red wine by osmotic distillation as a strategy to minimize the loss of aromas

Tempranillo red wines were partially dealcoholized (−3 v/v%) by osmotic distillation (OD) with membranes. First, polypropylene (PP) Liqui-Cel3M (3M) hollow fiber membrane modules were applied at 11 and 15 °C to study the effect of the removal of ethanol on the aroma of a certain wine. The influence of both temperatures was evaluated in terms of ethanol flux and aroma losses. Afterwards, two additional wines with different compositions were dealcoholized. The impact of the initial concentration of aromas on achieving a final product with an appealing aroma profile was studied, displaying the three wines a comparable aroma retention. Membrane OD was carried out with two additional hollow fiber membrane modules: another PP module (Zena) with a higher pore size, and a superhydrophobic PVDF module (Polymem). The latter gave rise to a partial dealcoholized wine with an aroma profile very similar to that of the pristine wine.

A novel on-site SMR process integrated with a hollow fiber membrane module for efficient blue hydrogen production: Modeling, validation, and techno-economic analysis

Steam methane reforming (SMR) is widely used in the hydrogen production industry; however, a significant amount of CO2 is released during this process. Several efforts have been made to produce low-CO2 hydrogen (blue hydrogen) via SMR; however, the proposed solutions are not applicable to small-scale plants. Therefore, this study proposes an on-site SMR process combined with a hollow fiber membrane module (HFMM) for CO2 capture in small-scale plants. First, mathematical models for the on-site SMR process and HFMMs were developed, and their accuracy was validated with real-world data. Second, we designed and implemented the SMR–HFMM model based on different operating conditions and gas compositions at three potential CO2 capture locations (dry syngas, PSA tail gas, and flue gas). The CO2 capture performances at these three locations were compared using five performance indicators: stage cut, separation factor, CO2 recovery rate, permeate composition, and retentate composition. Finally, to evaluate the integrated processes for each CO2 capture location, feasible ranges of the number of HFMMs and the levelized cost of hydrogen (LCOH) were calculated. In the case of CO2 captured in dry syngas, the number of HFMMs required to achieve a CO2 purity of over 90% was calculated to be 10–25. Furthermore, despite additional HFMM installation, the LCOH was 0.8%–1.5% lower than that of the conventional on-site SMR process that is 7.07–7.13 USD/kgH2. The proposed integrated SMR–HFMM process is a potential solution to the problem of CO2 emissions in on-site SMR processes with a lower LCOH. Therefore, the findings of this study could be of significant importance in improving the environmental sustainability of hydrogen production in small-scale plants.