R&D project VALHAGRO on green hydrogen from agro-industrial residues. Role of crossflow membrane filtration in water treatment and PEM electrolysis stability.
In most discussions around green hydrogen, the spotlight is placed on the electrolyzer. In real industrial settings—particularly when integrating streams derived from agro-industrial residues—the critical factor emerges earlier in the process: feed water quality.
This is precisely the perspective addressed in the R&D&I project:
VALHAGRO – Development and optimization of sustainable materials for green hydrogen production from the valorization of agricultural residues. The project is developed under a public–private collaboration frameworkand brings together NEOLIQUID, PERINOX, the University of Vigo and ITECAM.
Recent media coverage has highlighted the project’s potential to produce green hydrogen from agricultural residues and wastewater, reinforcing its relevance within circular economy strategies¹².
At its core, VALHAGRO addresses a structural challenge: how to coherently integrate waste valorization, water treatment, and hydrogen production within a single operational system. At that interface, crossflow membrane filtration becomes a defining element of process viability.
From residue to process water
Agro-industrial residues generate aqueous streams with clear potential as feedstock, but also significant complexity. These streams typically contain organic matter, suspended solids, and compounds that can interfere with downstream processes—particularly electrolysis .
The challenge is therefore not only to use these streams, but to make them compatible with process requirements.
If this step is not properly addressed, issues arise not at the design level but during operation: instability, increased fouling, and premature degradation of critical components.
Similar challenges are well known in other industries dealing with complex fluids, such as biotechnology, where separation and fluid quality control are essential.
👉 https://perinox.com/filtracion-tangencial-membranas-biotecnologia/
Crossflow membrane filtration as a design condition
In this context, crossflow membrane filtration goes beyond its traditional role as a separation step. Its function is not limited to solids removal or clarification—it contributes directly to process stability.
Operating under tangential flow conditions enables continuous treatment of complex streams while minimizing fouling and maintaining consistent performance. This translates into improved operational reliability and tighter control of feed water quality.
From an engineering standpoint, this represents a shift in approach: filtration is no longer an auxiliary unit, but an integral part of system design, influencing overall performance.
Water quality and electrolysis performance
PEM electrolysis systems are particularly sensitive to feed water quality. Even minor deviations can impact efficiency, accelerate membrane degradation, and reduce catalyst lifetime.
In this context, upstream water treatment is not an optimization step—it is a prerequisite for stable operation.
Industrial implementations typically rely on combined treatment strategies, including membrane filtration and polishing stages, as seen in water recovery and conditioning systems:
👉 https://perinox.com/filtracion-tangencial-membranas-recuperacion-agua-polisher/
Within VALHAGRO, this integration is addressed directly by combining water treatment and hydrogen production into a single system architecture, rather than treating them as independent processes.
Validation under real industrial conditions
A key aspect of the project is its focus on validation beyond laboratory scale. The integrated system—combining water treatment and hydrogen generation—will be tested at pilot scale in PERINOX facilities.
This approach enables evaluation under realistic conditions, including:
- Real process streams.
- Variable operating conditions.
- Interaction between different process units.
Ultimately, the objective is to assess system stability over time and its potential for industrial scaling.
A system-level perspective on green hydrogen
Projects like VALHAGRO highlight the need to move beyond component-level analysis when evaluating green hydrogen systems.
Performance depends not only on the electrolyzer, but on the coherence of the entire process, including:
- Feed stream characteristics.
- Water treatment strategy.
- Operational stability.
Within this framework, crossflow membrane filtration is not a marginal improvement—it is a core enabling technology.
The VALHAGRO project represents a step forward in integrating waste valorization with green hydrogen production. It connects agro-industrial residues with energy generation, while addressing the operational realities of industrial processes.
Among these, water quality and its conditioning play a central role. Crossflow membrane filtration becomes critical at this stage—not as an add-on, but as a condition for reliable and scalable operation.
For a deeper analysis of how crossflow membrane filtration impacts the technical and economic viability of industrial processes:
👉 https://perinox.com/en/tangential-flow-filtration-investment-volume-value-efficiency/
References
¹ https://www.lavozdetomelloso.com/69785/proyecto_valhagro_itecam_impulsa_nueva_generacion_hidrogeno_verde_partir_residuos_agricolas_aguas_residuales
² https://cadenaser.com/galicia/2026/01/14/la-uvigo-participa-en-un-proyecto-para-producir-hidrogeno-verde-a-partir-de-residuos-agricolas-radio-vigo/
(Proyecto CPP2024-011260 financiado por MICIU/AEI/10.13039/501100011033/ FEDER, UE)
