The Danish company NoTox A/S has supplied diesel particulate filters for nearly 10 years. Its NoTox® Diesel Particulate Filter is manufactured in silicon carbide, which combined with the thermal design, secures a filter monolith with unmatched durability.
The filters are mainly used in the retrofit of heavy duty vehicles but have many other applications as well. According to the company, while most diesel particulate filters are capable of removing soot from the exhaust of diesel vehicles, few have the durability of NoTox’s diesel particulate filters which are able to withstand the very demanding conditions prevailing during filtration of diesel exhaust.
In a demonstration in 1998, NoTox fitted a city bus with a filter system based on NoTox XD-90 filter substrate. The bus was in service until 2003, with the same filter substrate in place. The filter reached more than 700.000 km, without any deterioration of the filter.
The NoTox ceramic technology comprises a thorough understanding of the chemical and physical reactions involved in creating a highly porous structure of recrystallized silicon carbide. NoTox offers silicon carbide wall flow filters (WFF), primarily used for soot filtration in engine exhaust. The honeycomb design is also suitable as catalyst support, bed material for chemical reactors and other applications.
NoTox manufactures its filters in two different versions, targeted at different applications. According to the company, the filtration efficiency is above 97% in all the filter versions.
Its durable XD filters are most often used for filter systems with a passive regeneration strategy, where the filter may encounter very high soot loads before regeneration takes place. During regeneration at elevated soot loads, the filter structure experience high stress levels due to the energy release from the soot combustion.
NoToxs MD filters are often used for applications where active regeneration is employed. For this type of applications such as OEM use, where regeneration takes place under controlled conditions, a filter with less durability is required. This enables a filter design with more attention on reducing the pressure drop as much as possible.
NoTox says that it is constantly researching ways to improve its technology. It is in the process of developing filters for diesel exhaust which will contain new properties plus products for other applications.
NoTox A/S was acquired by Corning Incorporated from Silentor NoTox A/S in 2000 for a substantial amount of money. The acquisition helped the company advance the development of advanced diesel particulate filters for the automotive sector. And it gave Corning access to NoToxs silicon carbide filter design and production capabilities.
NoTox was the first to patent the technology that extrudes and fires coarse grained silicon carbide. This enabled NoTox to produce porous structures with pore sizes from a fewer microns up to more than 100 microns. Such a porous structure, constituted of particles, bonded together in the contact points, has a 100% open porosity, and no dead-end pores. The permeability of the NoTox material is therefore much higher than most competing filter materials, enabling us to provide more robust filters, with the same pressure drop as competing technologies. The raw materials used for the manufacture of NoTox silicon carbide filters are commercial grades of silicon carbide together with organic binders and additives
Automotive Industries spoke to NoTox Holdings chief executive officer Lars Frederiksen, and asked him what his plans for the companys future were.
AI: Do you plan to license your technology in markets in North America and Asia? If so, what time-frame have you drawn up?
We are like any supplier in the Automotive Industry, very focused on lowering costs and securing supply. We therefore need to have our production close to the markets, and are already exploring how to establish our self in both the Asian and North American market.
AI: What are your plans to increase your manufacturing capabilities in Denmark?
We have just announced that we take over a present production facility, today manufacturing brake components for the Automotive Industry. In this facility we will establish a large OEM aimed production. Start of OE production will be in 2007.
AI: Which industry does NoTox get the bulk of its revenues from? And how important is the automotive sector to your business?
We are today getting the bulk revenue, from retrofit players, producing filter systems for the off-road and on-road market. The Automotive sector represents a significant part of our growth strategy.
AI: What are some of the technological break-throughs we can expect from NoTox in the near future?
We expect technological breakthroughs, in particular in relation to gaining additional benefits, from our reduced demand for segmentation compared to other SiC filter technologies.
This will result in a further diversification of the NoTox filter range, and offer some competitive advantages that we expect will consolidate and strengthen our technology base further.
AI: How popular is your technology globally?
We are having customers in almost any region of the world, but our main customer base is for the being still European. We are now looking for partners in the US and in Asia.