ABSTRACT

Air pollution is a critical global public health and environmental challenge. With an estimated 8.1 million premature deaths annually, it ranks as the second leading cause of mortality worldwide. According to the World Health Organization, approximately 99% of the global population is exposed to air pollutant concentrations exceeding recommended guideline limits. Beyond its health impacts, air pollution also contributes significantly to environmental degradation and greenhouse gas emissions, largely driven by increasing urbanization and industrialization.

Conventional air treatment technologies rely predominantly on activated carbon, which accounts for nearly 90% of industrial air filtration applications for volatile organic compounds (VOCs) and odor removal. However, these systems suffer from several limitations, including limited performances, high energy consumption, substantial carbon footprint, rapid saturation leading to high maintenance requirement and tremendous waste generation. In the context of increasingly stringent European air quality regulations on industries, the development of advanced, efficient, and sustainable air purification technologies has become essential to sustain our industry while protecting the population health and the planet.

To address these challenges, Purenat has developed an innovative photocatalytic filtration medium inspired by diatoms, known for their exceptional photosynthetic efficiency. This biomimetic solution enables the transformation of airborne pollutants through oxidation and reduction reactions into harmless molecules like water vapor. Unlike conventional coated photocatalytic materials, the active agents are embedded directly within the fiber core of a textile structure, optimizing photocatalytic performance while preventing the release of secondary hazardous compounds. This approach offers a durable and cost-effective alternative to traditional air filtration technologies.

Over the past year, relevant pilot projects were conducted at industrial sites across France and Europe, covering diverse sectors including livestock farming, food processing, chemical manufacturing, and the fragrance industry. These trials were performed under real operating conditions to evaluate the efficiency, robustness, and industrial scalability of the photocatalytic filtration system. The main outcomes can be summarized as follows:

• High Performance

The system demonstrated strong depollution efficiency for complex mixtures of volatile organic compounds, involving dozens of distinct pollutants. High abatement efficiencies were observed for a wide range of carbon-, oxygen-, and hydrogen-based compounds, including odors, alcohols, aldehydes, ketones, aromatics, and mercaptans, under single-pass industrial operating conditions.

• Versatility and Integrability

The filtration units showed strong adaptability to existing industrial infrastructures and were designed to be directly connected to current air treatment installations, requiring minimal retrofit. Real-time monitoring of inlet and outlet VOC concentrations enabled on-site performance assessment and operational parameter adjustment during pilot operation.

• Energy Efficiency, Durability, and Maintenance

The technology exhibited a significantly reduced energy demand compared to actual conventional air treatment systems, characterized by low pressure drops. Photocatalytic activation relies on low-energy UV-A LED sources and requires only a standard 16 A electrical control unit, indicating limited electrical power demand. Owing to the non-saturating nature of the photocatalytic degradation mechanism, maintenance requirements were substantially reduced, with filter replacement required only after approximately 25,000 hours of operation, thereby limiting operational downtime and waste generation.

In response to increasing regulatory, environmental, and public health constraints, these results highlight the potential of photocatalytic textile-based filtration as a robust and scalable approach for industrial air treatment. By combining high depollution efficiency, operational flexibility, and reduced energy and maintenance constraints, this technology addresses key limitations of conventional air purification systems and opens new perspectives for sustainable industrial air quality management.