KEYOU Winner of the "International busplaner Sustainable Award" in the Category „Hydrogen Bus".  Read more.
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“There are plenty of reasons to combine the internal combustion engine with hydrogen”

The combustion properties of hydrogen help the internal combustion engine to reach new heights: initial results from research with different hydrogen engines have shown effective efficiencies of 50 % at the crankshaft. With the benefits of lean burning (six times the laminar burning rate of petrol blends) and the wide flammability range of hydrogen in air, it is also possible to achieve incredibly efficient partial load operation. Immense consumption savings can be made in comparison to conventional internal combustion engines.

Hydrogen has a higher energy content than all other conventional fuels: burning 1 kilogramme of hydrogen releases the same amount of energy as burning 2.75 kilogrammes of petrol. When it comes to gravimetric energy density (energy content per unit of mass kWh/kg), hydrogen again scores highly when compared directly to the energy sources used as standard today. In terms of specific energy density, a hydrogen-powered internal combustion engine has the edge on a drive train with a fuel cell. Current developments show that this advantage has not been exhausted to a full extend, yet. A further and even improved ratio between gross vehicle weight to power output can be achieved with low additional effort. Furthermore, the hydrogen combustion engine is also in a better position than the electric battery drive. A study conducted by the Friedrich-Alexander University of Erlangen-Nuremberg (FAU) reached the conclusion that “it is (currently) not feasible to introduce electric battery drives to cope with the continuous growth in long-distance road haulage and the HGVs and semi-trailers used in that sector. The power density of a battery is too low to provide the required haulage capacity or cover the necessary range (> 500 km).”

The combustion process developed by KEYOU allows hydrogen to burn with atmospheric oxygen to produce water with no emissions. This is because hydrogen does not contain any carbon, which in turn means that carbon-based pollutants emitted from conventional vehicles are never produced by a hydrogen engine. The necessity for increasingly complex exhaust gas after-treatment procedures ceases to apply to KEYOU-inside engines, thus decreasing production and maintenance costs. KEYOU has entered into a development partnership with Nagel Maschinen- und Werkzeugfabrik GmbH in order to tackle the issue of how to reduce the combustion of lubricating oil to an optimum level. Nagel, the world’s leading specialist in the field of honing and superfinishing technology, has been crucial in achieving the stated development objectives. Furthermore, it has also been possible to solve the problem of nitrous gases (NOx). NOx-compounds are the only exhaust emission components that have to be considered in regard to hydrogen engines, since they form bonds with atmospheric nitrogen at high combustion temperatures.KEYOU uses hydrogen’s unique combustion properties to its advantage, moving through the engine operating map with excess air at all times. This operating strategy gives rise to only small amounts of nitrogen oxides, which are already far below the strict Euro 6 emission limits – even without exhaust gas after-treatment. KEYOU has developed an innovative exhaust gas recirculation system to almost entirely avoid nitrogen oxide production within the combustion process. In combination with a special H2-SCR system, it guarantees zero emissions. Or to put it another way, every vehicle equipped with the H2-SCR system and KEYOU-inside technology is not only clean by itself, it additionally purifies the heavily polluted urban air too.

Unlike electric vehicles, no precious, rare or toxic materials are needed to produce internal combustion engines, just very common ones. Internal combustion engines and conventional gearboxes are not tied to specific raw materials or producing countries either, since steel and aluminium dominate the landscape here, with plastics increasingly being used for add-on parts. The production process is simple and has been refined down to the smallest detail. At first glance, an electric car seems clean, above all because it has no exhaust. However, if we look at the CO2 emissions produced over the entire vehicle life cycle, the picture regarding environmental impact is much worse. This is primarily because it takes twice as many raw materials and twice as much water – not to mention lots more energy – to produce the batteries used in electric vehicles than it does to manufacture a conventional vehicle. Additionally, if a battery electric vehicle is charged from the German fuel mix, its CO2 emissions covering both production and service life are higher than for a comparable diesel vehicle.The Institute for Energy and Environmental Research (ifeu) in Heidelberg is researching the carbon footprint and life cycle analysis of electric vehicles. In its study titled “The environmental consequences of electric vehicles (Ökologische Folgen von Elektroautos)” they point out the currently poor environmental performance of battery electric vehicles. There are other investigations that cast a critical eye on the life cycle analysis of electric vehicles too; for example, the study commissioned by the German Federal Ministry of Transport and Digital Infrastructure and carried out by the Fraunhofer Institute for Building Physics concluded that, during the production phase alone, 60 % more CO2 is generated when manufacturing electric vehicles than those with internal combustion engines: “This is down to the battery system and, above all, the mining, processing and production of the high-tech materials used in the battery cells. These substances are associated with a much greater environmental impact than the materials found in the rest of the vehicle.”A KEYOU drive system, which is powered by H2 produced from renewable energy, has lower CO2 emissions throughout its life cycle than fuel cell electric vehicles or pure electric vehicles. Furthermore, hydrogen combustion engines give no cause for concern in terms of raw materials: they require neither rare-earth metals nor cobalt.

“Our innovative hydrogen technology is making the internal combustion engine green”

For the first time on a physical diesel engine, KEYOU hydrogen technology has shown how the right technological approach of combining efficient injection, exhaust gas recirculation, turbocharging and a patented hydrogen catalytic converter, can turn conventional diesel engines into emission-free hydrogen ones. This was achieved with only a small number of modifications to the basic engine. KEYOU succeeded where other manufacturers have failed so far by elevating the relationship between efficiency and power density to a whole new level, thus resolving the conflicting objectives of zero emissions, efficiency and economic viability almost completely.

The blue components indicate the KEYOU core components that have been specifically adapted for to retrofit and existing diesel engine allowing it to burn hydrogen. Integration, adaptation and optimisation are the key throughout the whole KEYOU development process and, as such, are essential in transforming an engine powered by conventional fuel into a hydrogen powered engine.

Key-components of the KEYOU-H2-Technology

Integration of:
+ H2-Ignition system
+ H2-Fuel system
+ Aftertreatment of exhaust gas		 Adjustment & optimisation:
+ Turbocharging system
+ Exhaust gas recirculation
+ Compression ratio
+ Combustion chamber
+ Engine control unit
Adaptation of materials:
+ Valves
+ Valve seats

“Diesel is the benchmark. And we need to surpass it”

The unique advantage of the KEYOU solution is that vehicle manufacturers can continue to use their existing production and development infrastructure, whilst offering their customers emission-free vehicles whose total cost of ownership will ideally stabilise at the same level as today’s diesel vehicles.

This will make clean mobility affordable for end customers for the first time ever, and without compromising on customer benefits: range, availability, payload/number of passengers and air conditioning functions are all top class compared to those offered by a conventional diesel vehicle. Both, mankind and the environment are the big winners here.

Customer Benefits and Costs:

Range: > 500 km
Engine power: > 200 kW
Availability: > 95 %
Operational lifetime: > 700,000 km
Total cost: ≈ Diesel engine

Local Emissions:

Only water-vapour
CO2-free
No particulate matter

“KEYOU-inside H2 technology – the smart solution for new vehicles, which can also be retrofitted into existing ones”

Today, commercial vehicles still emit large quantities of CO2 and pollutants. At the same time, climate targets and CO2 regulations are becoming tighter and future bans on diesel-powered buses and trucks entering inner cities are increasingly likely. Despite tight budgets regional fleet operators, transport organisations and bus companies are therefore increasingly faced with the challenge of reducing emissions.

With its H2-based technology, KEYOU is now enabling established vehicle manufacturers to offer their customers new zero-emission vehicles that come at an attractive price and are incredibly well suited to everyday use. Even existing vehicles already in the field can be converted into zero-emission vehicles with the help of KEYOU’s H2 technology. This gives bus- and truck-operators a flexible tool to gradually transform their own fleets into vehicles fit for a new zero-emission age.

Technology Platform:

Diesel- and petrol engines
Manufacturer-independent
Performance-independent
Engine-independent

Target Market:

Utility vehicles: Buses and trucks
Vehicles: New and old vehicles
Customers: Engine manufacturers
Vehicle manufacturers
Public transportation
Fleet operators