Technologists develop robust soot filter for diesel engine

In a Technology Foundation STW project, Coen van Gulijk has developed a new concept for a robust soot filter for diesel engines. As well as filter stages, the filter has an open canal so as to exclude the danger of blockage and thus fire.

The new soot filter consists of series of perforated ceramic foams. The surface of the ceramic is impregnated with a catalyst on which the incoming soot particles are burnt and released as gases. Ash particles from impurities in the diesel, which enter the filter with the soot, remain in the pores of the ceramic foam plates. The ceramic foam can absorb a large quantity of ash before it risks becoming blocked and can therefore be used for a long time. The filter is highly suitable for removing soot from so-called heavy diesel oil. Heavy diesel oil is a heavy fuel containing many minerals and metals which produce ash. Existing filter systems would become blocked if used with heavy diesel oil.

As the filter is built from separate filter plates instead of a single block, it is almost indestructible. Even if all of the plates were to break, the filter function remains intact. An inbuilt open canal prevents the filter from becoming blocked. However, a disadvantage of the design is that it requires a lot of space. This means it is not suitable for cars but it can be used for ships, which often use heavy diesel oil, as equally fixed motors or trains.

The design of the new filter is partly based on studies concerning the form and size of soot particles. Diesel particles have a structure which consists of branched lumps of soot chains. Research has shown that due to this fractal structure, diesel particles are in fact up to ten times bigger than is indicated with measuring instruments. This was established with the aid of an electron microscope. Accordingly the behaviour of the soot particles relevant to the filtering is different than was thought; they diffuse more slowly but are more likely to stick to the filter.

With effect from 2005, the statutory health standards for soot emissions from cars will be just 0.025 gram per kilometre. Due to improved insights into the performance of measuring instruments, it will in future be possible to draw up legislation based on the number and size of the particles.

The new filter distinguishes itself from current filters because the reliability was the starting point for the design rather than the filtration efficiency. In commercially available filters the opposite approach is used.

Media Contact

Michel Philippens alfa

All latest news from the category: Process Engineering

This special field revolves around processes for modifying material properties (milling, cooling), composition (filtration, distillation) and type (oxidation, hydration).

Valuable information is available on a broad range of technologies including material separation, laser processes, measuring techniques and robot engineering in addition to testing methods and coating and materials analysis processes.

Back to home

Comments (0)

Write a comment

Newest articles

Advancing materials science with the help of biology and a dash of dish soap

High-speed X-ray free-electron lasers have unlocked the crystal structures of small molecules relevant to chemistry and materials science, proving a new method that could advance semiconductor and solar cell development….

Zeolite nanotube discovery made by researchers at Georgia Tech

Zeolites, which are crystalline porous materials, are very widely used in the production of chemicals, fuels, materials, and other products.  So far, zeolites have been made as 3D or 2D…

Impossible material made possible inside a graphene sandwich

The design of new materials allows for either improved efficiency of known applications or totally new applications that were out of reach with the previously existing materials. Indeed, tens of…

Partners & Sponsors