NOx-Mitigation Technology for Retrofitting Diesel Engines
Alsitek Limited works on the commercialization of an innovative polymer-foam filter system for mitigating more than 85% of NOx emissions from diesel engines. The aim of the Phase 1 project is to confirm the technical feasibility and commercial potential of this ground-breaking retrofit technology to ensure a smooth transition towards a fossil-fuel-free economy in Europe. The current concerns about the health effects of vehicle emissions and the scandal around manipulated diesel engine emissions in passenger cars shows there is a need for disruptive and timely solutions.
The Alsitek NOXTEK solution is a retrofit technology that goes beyond the current state of the art in terms of NOx mitigation (over 85%), with the capability to absorb large amounts of NOx over long time and excellent regeneration capabilities. NOXTEK meets several end-user needs in the diesel passenger cars market, including:
- an efficient NOx-mitigation solution to ensure compliance with the tightening environmental regulations
- the need for an ergonomic retrofit solution not affecting the warranties of the car’s subsystems and components
- a solution that can be applied in a de-centralized manner by technically adept end-users or at service points. The product is expected to be 78% more cost-effective than available retrofit solutions. Alsitek aims to target the diesel passenger car aftersales market first (to be confirmed in Phase 1). Adjacent markets to be targeted include diesel engine applications in low and heavy-duty vehicles, marine vessels and peaking power plants.
NOXTEK is expected to save 6.2 tons of NOx emissions annually from the fifth year after market entry, which is an equivalent of 1847,6 tons of CO2. The Phase 1 work will focus on confirming the priority market for commercialization, conducting a feasibility for SMEi Phase 2 scale-up and demonstration, as well as work on strengthening Alsitek’s patent position and scouting on external manufacturing capabilities.
High-performance filter to reduce in-car air pollution
EU-funded researchers have designed an anti-pollution filter that quickly removes dangerous exhaust fumes such as nitrogen dioxide (NO2) from inside vehicles.
Nitrogen oxides and particulate matter make up a great proportion of pollutants emitted from cars. Exposure to these pollutants can lead to major health issues such as stroke, heart disease, lung cancer and respiratory infections.
Until now, it was believed that air pollution exposure levels are higher when people cycle or walk than when they are sitting inside a vehicle. A growing number of new findings run counter to that conventional wisdom, showing that air pollution levels inside a vehicle often exceed the accepted exposure limits for both NO2 and particulate matter. These hazardous pollutants mainly stem from the exhausts of other vehicles.
The EU-funded project NOXTEK addressed this situation by using cutting-edge nanomaterials to create an air filter. It acts as a highly effective molecular sieve for removing NO2 from polluted air flows. “The breakthrough technology reduces in-car concentrations of NO2 by up to 98 %,” notes John Pickstone, operations director at Alsitek, the UK company producing NOXTEK.
State-of-the-art air treatment
Growing awareness and concerns about the health effects of vehicle emissions as well as exhaust emissions in some diesel vehicles reflect a strong need for disruptive and timely solutions. Currently, some cars have built-in filtration systems with activated carbon filters. “However, activated carbon layers are not selective about the types of particles that pass the air conditioner; they often trap harmless gas species, leaving troubling pollution particles like NO2 pass through,” notes Pickstone.
Temperature and relative humidity have a great impact on the adsorption capacity of cabin air filters. In particular, the ability of activated carbon to function efficiently is severely affected when ambient humidity exceeds 50 %. At humidity levels above 75 %, the filter becomes less efficient. To make matters worse, the production of activated carbon has detrimental environmental impacts.
Higher protection against pollutants
Recognising the importance of improving air filtration inside the vehicle cabin and its negative impact on occupants’ health, Alsitek developed an eco-friendly inorganic polymer-foam filter. This can remove toxic NO2 gas from incoming air streams with efficiency as high as 98 % at a single pass. Its product is based on both physical adsorption (physisorption) and irreversible chemical reactions (chemisorption). The main advantages of chemisorption are that the pollutant is irreversibly captured, it is independent of the compound's molecular weight, and operates under a wide range of temperature and humidity levels.
The high selectivity of this molecular sieve is determined by its high porosity – molecules with diameter less than the pore size of the structure will be absorbed while larger molecules will be excluded. The product may look similar to existing technology but demonstrates improved performance on all fronts. Its price is comparable with activated carbon, with significant potential to take the lead from that competing technology.
While NO2 emissions mainly stem from road transport, these harmful pollutants can also arise from many industrial sources as a result of combustion processes. Therefore, NOXTEK’s new filter technology can also find use for treating industrial emissions, and exhaust gases of ships and trains.