The air filtration method reducing the impact of pollution

The air filtration method reducing the impact of pollution
© iStock / ermingut

Smart Separations has created a low-cost and versatile air filtration method for separating micron-sized particles.

This novel technology has a wide range of applications across multiple industries, such as stem cell and blood research, the lowering of industrial emissions, and food and drink processing. Indoor air purification filters taking advantage of this air filtration method are our first products to market.

The indoor air pollution challenge

Air pollution poses a significant threat to our health. Its effects range from short-term, such as eye irritation or coughing, to long-term effects, such as respiratory infections, cancer, dementia and even death.

According to the World Health Organization (WHO), outdoor air pollution is estimated to have caused at least 3.7 million premature deaths worldwide in 2012, but this could be high, if links to Alzheimer’s and dementia are considered. Some 88% of these deaths occurred in low- to middle-income countries, with the greatest number occurring in the Western Pacific and Asia regions. The monitoring of outdoor air pollution has shown that air quality fails to meet WHO guidelines for safe levels in most cities worldwide, putting people at additional risk of respiratory disease and other health problems.

The air quality and micro-particulate problem is so critical that the European Commission adopted an important directive in 2013, the Clean Air Policy Package, highlighting the enormous impact poor air quality has in Europe. The Commission estimates 58,000 deaths per year can be avoided through the implementation of better policies, saving between €40 and €140 billion in external costs and providing €3 billion in direct benefits due to higher productivity of the workforce, lower healthcare costs, fewer work sick days and less damage to buildings.

One of the leading causes of poor air quality in many cities is emissions of micro-particulates from industry and car exhausts. Micro-particulates are defined as PM10 (particulate matter with 10µm or less in diameter) and PM2.5 (2.5µm or less in diameter) both of which have been deemed a grave hazard to our health.

The importance of indoor air pollution is often ignored despite estimates showing that people spend 87% of their time indoors. Indoor air quality refers to the quality of air in a home, school, office, or other building environment. Sources of indoor pollution are not only ambient or external; indoor pollution and inadequate ventilation are also significant contributors to poor air quality.

Tobacco smoke, mould, and chemicals released from synthetic fabrics, furnishings, synthetic building materials and household cleaning products (such as aerosols used as ‘air fresheners’) are just some of the sources of contaminants that can sometimes make indoor air quality worse than outdoor air, where pollutant concentrations are often two-to-five times higher. A unique air filtration method is one of the only ways to tackle this issue, which may prove vital.

Appropriate indoor air quality, defined as absence of air contaminants/pollution which may impair the comfort or health of building occupants, can reduce the incidence of respiratory problems, allergies and health conditions. At the same time, poor air quality can increase stress levels and affect our mental health (e.g. sick building syndrome) – resulting in low productivity levels.

A novel solution

Smart Separations Ltd (SSL), a London-based company, has developed a unique air filtration method to separate micron-sized particles. This is a proprietary filtration technology based on a novel adaptation of long-established ceramic filters tailored to suit a wide range of different markets and industrial applications. By combining the filters’ high surface area with novel coatings, a unique air filtration method is developed, which can greatly improve air quality.

The functionalised filters allow for the production of novel membranes with electrically‐conductive properties mobilised with active nano-catalytic chemicals that can dually filter out dangerous micron-sized particles (PM2.5 and PM10) and ‘scrub’ or decompose chemicals in air passing through pores to remove odours/smells, dust, pollen and toxic compounds. By removing these emissions, our technology will bring great benefits through improved indoor air quality, with a more efficient and lower-maintenance system than rival fibre-based filters and air scrubbers.

SSL membranes consist of highly ordered microchannels self-assembled in two stages of fabrication – a technique protected by two patents granted in the UK. The process has also been designed to eliminate problems associated with conventional membrane designs by improving membrane performance and durability. The patented manufacturing process is both scalable and cost-effective and the structure can be controlled to a high degree without secondary processing or sophisticated equipment, which will reduce costs and widen applicability. This creates a filter with pores that traverse the entire membrane cross-section in the microfiltration range (i.e. 0.2 to 50μm in diameter).

The second manufacturing stage involves removing a controlled thickness portion of both surfaces of the membrane to end up with a flat ‘cleanable’ surface as well as a specific pore size opening, tightly correlated to the amount of material removed – and tailored to customer/application sector requirements. This patented combination of a unique microstructure and controlled surface abrasion enables the creation of a unique filter with tailored ‘flared’ or ‘conical’ pore sizes to suit different needs. High pore density and good mechanical strength reduces incidences of clogging and, more importantly, can reduce costs of manufacturing and allow pore sizes that heretofore were difficult to achieve in a ceramic substrate.

Our research has shown that by using our filters air purification can be done in a small low-energy device without the need for larger energy-intensive solvent systems or combinations of devices. These normally add to costs and energy consumption. Our revolutionary concept is a three-step system in a single filter (prefilter, dust collector and air purifier) with applications in a myriad of markets and of great benefit to society, the environment and the air purification sector in particular.

Rival technologies

Current membranes/filters use polymeric or fibre-based materials, which have many limitations: they are not readily suitable for micron-sized particle separation (as they lose stability) and they cannot withstand high temperatures or harsh chemical conditions (otherwise useful for cleaning and industrial emissions from various industrial processes). Hence, these present significant drawbacks: low chemical resistance, significant pressure drop, they cannot be coated or functionalised, they have a short life-cycle (typically six months) and they have a requirement for low temperature, regular maintenance and dry feed.

SSL filters are more efficient than these rivals. Because of its unique conical shape, SSL’s unique filter technology circumvents the inherent limitation of flow rate (i.e., pressure drop) that a separation layer introduces to existing devices. In addition, and in contrast to other filters on the market, our filters will be easily cleaned at source for reusability: using magnets, the end-user can simply and safely detach the filter unit and wash it using a simple dishwasher cycle or clean it under warm tap water if this is not readily available.

Wood burning stove tests have demonstrated how efficient our air filtration method is at reducing microparticulates. Tests at the UK certification body, BSRIA, have resulted in a high (over 96%) reduction of microparticulates (i.e. PM2.5 and PM10) from wood burning stoves – with clear indication that our filters could capture more microparticulates than current standards require (±30% more).

Some of our additional differentiators versus competition are:

  1. A filter that can easily be retrofitted into existing systems;
  2. A functionalised filter that provides better quality of life through improved air quality (removing dangerous microparticulates, bad smells and pollutants all in a single filter); and
  3. A filter that reduces maintenance requirements as well as heavily reduction to landfill waste, by extending the shelf life of filters from the current six months to at least five years.

Conclusions

Other industries are also eager for a product solution such as the one we are introducing here. These include: reduction of emissions from wood burning stoves; air testing/car debris filter; gas and oil industries; domestic use (e.g. in a vacuum cleaner); in gas hobs to provide more efficient gas burning; as an allergen filter, (e.g. for asthma); as a pollen filter for air conditioning and other similar applications; as a self‐cleaning filter for, for example, automotive applications (relying on the ruggedness and non‐clogging nature of the ceramic disk); and cancer research and the biotechnology sectors, amongst many others.

These industries will benefit from our versatile air filtration method and its unique selling points, particularly the ability to tailor the microfiltration pore size in accordance with customer requirements, a strong ceramic support that can be functionalised with a wide range of capabilities, including easier cleaning. Moreover, this technology addresses a key current issue: the need for better, more efficient and cheaper solutions to remove micron-sized particles and break down pollutants for cleaner, less harmful and healthier indoor air.

Hugo Macedo
Founder & CEO
Smart Separations Ltd
London
+44 7590698705
hugo@smartseparations.com
https://smartseparations.com/

This is a commercial feature which will appear in Government Europa Quarterly 26, available in July.

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