Xeamos is a firm of engineering consultants. All our systems have been developed and tested in-house. We, therefore, do not sell systems of other suppliers. We also have expertise in-house with regard to noise reduction and diesel particulate filters and SCR technology so that we can combine them in one system. The results of models that have not been supplied before by our engineers are calculated in advance using special software so that the correct operation can be guaranteed. If required, we will calculate the pressure drop of the entire exhaust system and perform thermal and/or strength calculations. We are also fully up-to-date about the regulations in the area of emissions, safety, etc. You will, therefore, buy a system from us for which the operation and service life have been determined in advance.

Xeamos systems are special because they are specifically aligned to the intended use. Our systems are exactly aligned to the engine type, the load profile of the engine, the fuel type, the integration space, and the specific requirements set by the user. This is the reason why we supply a large variety of systems instead of offering one standard system for multiple applications. Because of this, an after-treatment system for luxury yacht building is very different from a system for inland navigation vessels.

The components that we use are of industrial quality. We may perhaps not be the cheapest, but, in the long-term, you will make back more than your return on investment because of the low operational and replacement costs.

An Xeamos MPAT system consisting of an SCR catalytic converter that may or may not be combined with a diesel particulate filter is aligned with the engine. Within this context we take the allowed back pressure into account. A catalytic converter can normally not become blocked so that the back pressure will remain the same as time goes by. On the other hand, a diesel particulate filter might become blocked if there is an unexpected fault. The reason could be a faulty component that means that active regeneration does not operate, but it could also be a faulty injector or excessive lubricant consumption of the engine, that is, a sooty spanner has literally been thrown into the works! You cannot tell when there is an issue with the engine when there is a diesel particulate filter, all particulate is collected and you only notice the problem when the back pressure becomes too high. This can result in damage to the engine. Therefore, all Xeamos diesel particulate filter systems are equipped with a safety bypass valve. It will open when the back pressure is too high and it will then close automatically. The valve will open as much as is required to maintain the correct pressure. This ensures that no more exhaust gases are bypassed than are strictly necessary.

You can see when the bypass valve has been opened and closed in the alarm history where this information is saved. An alarm will, naturally, be sounded when the back pressure is too high.

Low Saps stands for “Low Sulphated Ash and Phosphor” which means a lubricant with a reduced quantity of sulphated ash, phosphorus and sulphur. The specific benefit of this type of lubricant for diesel particulate filter systems is that the maintenance interval can be extended. In addition, the service life of diesel oxidation catalysts and coated diesel particulate filters is extended. You can use a quality lubricant with an Xeamos SCR system without diesel particulate filters.

Always consult your engine and lubricant supplier for information about the correct lubricant type for your engine.

GTL stands for Gas-to-Liquid. This is fuel converted from natural gas using a synthetic method. This fuel is, therefore, very pure. Our experience is that using GTL has a clearly positive effect on particulate emissions and a somewhat positive effect on NOx emissions. This fuel can be used to perfect advantage with our diesel particulate filter and SCR systems. For more details about the fuel, please refer to the information of the GTL suppliers.

Just changing from EN 590 to GTL is not sufficient to meet stricter emission requirements such as the EU Stage V or IMO III. After-treatment in the form of an SCR catalytic converter and/or diesel particulate filter is still required. On the other hand, a combination of a GTL and an SCR system can ensure that a pre-CCR or a CCR1 engine (for inland transportation) meets current CCR2 emission requirements. We will gladly provide advice regarding this.

LNG stands for Liquefied Natural Gas, or: natural gas that has been made liquid by pressure and used as fuel. Natural gas becomes liquid at temperatures below -162 °C. The significant advantage is that liquefied gas has a much lower volume for the same energy content. 1 m3 of LNG equals 600 m3 of gaseous natural gas.

LNG is stored and transported in what is commonly referred to as cryogenic tanks to keep the temperature of the gas so low. Cryogenic tanks consist of a double wall where the space in-between the inside and outside tank is a vacuum. This wall is provided with special insulation material.

A slight heat supply from outside to the inside will occur because the insulation value of the tank can never be endlessly high. This means that a small quantity of LNG will evaporate continuously. If there is no take-up of gas for the engine, a “blow-off” gas will occur. By preference, this blow-off is used to, for example, drive a generator so that no natural gas is blown off to the atmosphere.

To be able to use LNG, it must first be evaporated where it is converted into gaseous natural gas. There are two engine types that can run on LNG.

You can, for example, operate with gas engines in combined heat and power systems. These engines have a spark ignition. The advantage is that these engines are fully aligned with gas as regards compression, ignition, valve timing, etc. The disadvantage is that these engines usually show a poorer dynamic behaviour.

You can also convert a diesel engine into a dual-fuel engine. In these engines the natural gas is injected into the combustion air before the turbo. A slight quantity of diesel is injected into the combustion space to ignite the gas/air mixture. These engines usually run on 5 to 20% of diesel and 80-95% of natural gas.

The NOx and particulate emissions are much lower with regard to a gas engine and a dual-fuel engine when compared to a 100% diesel engine. However, NOx and particulates are still emitted. Depending on the engine and the application, an SCR and/or diesel particulate filter system may still be required to meet future regulations.

A vessel’s hybrid drive is characterised by the fact that a combination is made of a conventional direct drive and an electric drive. The propeller is basically directly driven by a propulsion engine. In addition, the propulsion engine is supported by an electric motor that is installed directly on the propeller or is connected through a gearbox. The electric motor, in turn, must be fed by a generator. Depending on the required propeller power, the propeller is driven by the electric motor/generator, the main engines, or both. Within this context, the actuated engines/motor are favourably loaded (that is: higher than 50%) and the system prevents the engines/the motor from running at the bottom of the load area when they are the most polluting and consume more fuel in relative terms.

The load or sailing profile must be analysed exactly because, in the process from generator to electric motor, energy is lost with regard to a hybrid drive. It can generally be stated that this method is mainly effective when there are large differences between the normal and peak loads. Tugboats and excursion vessels are examples of this.

Combinations can also be made with a battery pack to deal with peak loads (peak shaving). This means that a smaller generator can be chosen and you can only sail electrically for short periods of time.

This is beneficial for the combination with post-actuated technologies because the relative engine load of the actuated engines is high. This often means that active regeneration of the diesel particulate filters is not required on the generator.

With regard to diesel-electric propulsion drives, the propeller is only driven by an electric motor. The required electric power is generated using two or more generators that are actuated depending on the power demand.

The load or sailing profile must be analysed exactly because, in the process from generator to electric motor, energy is lost with regard to this driving method. It can generally be stated that this method is mainly effective when there are large differences between the normal and peak loads. Tugboats and excursion vessels are examples of this.

Combinations can also be made with a battery pack to deal with peak loads (peak shaving). This means that a smaller generator can be chosen and you can only sail electrically for a short period of time.

This is beneficial for the combination with post-actuated technologies because the relative engine load of the actuated engines is high. This often means that active regeneration of the diesel particulate filters is not required on the generators.

Xeamos offers the option to, for example, connect two generators (< 600 kW) on to one MPAT system. This saves on costs and space.

Xeamos can supply different types of diesel particulate filter and catalytic converter systems. Our strength is in smartly combining both systems where noise reduction is not forgotten. For example, we can supply SCR catalytic converters with integrated noise reduction of 35 or 45 dB(A). Our MPAT systems have also been designed in such a way that they have a noise reducing value that is between 40 and 45 dB(A). Diesel particulate filter systems and catalytic converters, by their nature, already have a reasonably high noise reduction. The reduction, however, mainly lies in the middle and higher frequency spectra. The reactor housing has been designed in a specific manner to attain sufficient reduction at the (lower) ignition frequency and what is commonly referred to as the first harmonic. Noise reduction of lower frequencies, however, always costs volume.

We also supply systems that have a lower reduction level because of their compactness. These are then combined with a wet exhaust system or a standard post silencer.

For noise-reducing device replacing systems such as the Xeamos MPAT system, the length of the system is not, or only slightly, larger than a regular noise-reducing device. However, the total external area is larger because the housing is rectangular. The heat emission will, therefore, increase with regard to a refit project when identical insulation material is used. If the engine room ventilation is just sufficient with the current noise-reducing device, we recommend using thermal insulation with a higher insulation value. The insulation type and value can be determined in consultation with you.

Xeamos has developed a unique Multi Engine Valve (MEV) system with which two or more engines can be connected to one MPAT exhaust gas after-treatment system. This system ensures that the exhaust gas pipe of a switched-off engine is shut-off in a safe manner to prevent the exhaust gases of the running engine flowing back. The system is mainly interesting for motors with a power that is lower than 600 kW per item, for example, with regard to diesel-electric propulsion drives. Combining multiple engines on one MPAT system saves on space and costs. You can also connect the generator to the system on an inland navigation vessel. You will then no longer be inconvenienced by the particulates from the generator and you will sail completely green.

Several vessels have now been equipped with this system. We will be glad to advise whether this solution could be of interest to you.