Catalytic converters for gas engines

When there’s a need to reduce emissions of carbon monoxide and hydrocarbons from a gas engine in order to comply with environmental regulations, a ‘two-way’ catalytic converter is the answer. On some engines it’s even possible to install a ‘three-way’ catalytic converter which will also reduce oxides of nitrogen. Blackthorn’s catalytic converters can normally reduce toxic emissions by over 90%.

Catalytic converters are simple to install and have no consumables. In most cases they don’t even require maintenance and will operate for 10,000 running hours or more.

Two-way catalytic converters are designed for lean-burn engines, but the three-way version can only be used on engines which run neither lean nor rich i.e. they are ‘stoichiometic’. Customers wishing to reduce oxides of nitrogen on lean-burn engines will require an SCR system.

Blackthorn can design and supply catalytic converters for gas engines of any size, running on CNG, biogas or syngas. We can predict the increase in pressure drop related to the catalytic converter and normally aim for no more than 10 millibar, although we can achieve less than this if necessary, by increasing the diameter.

Catalytic converters only work when the exhaust gas passing through them is hot, and a typical minimum temperature is 250 °C (or 450 °C if methane oxidation is required). Therefore, they need to be installed at a point in the exhaust system where the exhaust gas temperature is normally over this level, and reaches it soon after a cold start, meaning the best location is usually upstream of the silencer. They must be protected from engine vibration so there should always be a bellows between the engine and the catalytic converter.

If the fuel gas contains contaminants such as sulphur, it is best to filter these out of the gas before it reaches the engine, otherwise they will have an adverse effect on the catalytic converter. Blackthorn can supply special coatings which can tolerate sulphur, but the substrates will require periodic cleaning. In these situations, we normally design them so that the substrate can be removed easily from the housing.

Catalytic converters are completely passive, i.e. they do not require a power supply or any fuel additives. As no commissioning is required, we can supply them to customers anywhere in the World.

Blackthorn has been supplying catalytic converters for gas engines for over 20 years, but we have also kept up with changes in technology and therefore make use of nanotechnology coatings, which provide high levels of efficiency whilst being economical in terms of precious metal content. We are used to making one-offs and small batches and look forward to receiving your enquiry.