Honda plans four "next generation" power plants
October 2006
Honda has announced four “next-generation” power plant technologies, aimed at reducing CO2 emissions.
Honda’s next generation clean diesel engine is claimed to be able to reduce exhaust gas emissions to a level equal to that of a gasoline engine using a “revolutionary” NOx catalytic converter that is entirely self contained, generating its own urea as opposed to requiring an outside source to be added.
The system works via a two-layer structure, with the first layer absorbing NOx from the exhaust gas during lean-burn operation and converting a portion of this into ammonia. This is done by first having the engine management system adjust the engine air-fuel ratio to rich-burn, at which point the NOx in the adsorption layer reacts with hydrogen taken from the exhaust gas, producing ammonia.
The second layer then absorbs this ammonia, and switching back to lean-burn mode, reintroduces it in a reaction that converts the remaining NOx into harmless nitrogen (N2).
By generating and storing its own ammonia, removing the need for additional storage and measuring systems, Honda’s catalytic converter is made compact and light. The system also has enhanced NOx reduction performance at 200-300°C, the main temperature range for diesel engines.
Honda’s catalytic converter has been designed for use with its 2.2 i-CTDi diesel engine, first introduced in 2003 in the European Accord model. Honda has announced that it is hoping to introduce its next generation diesel engines in the US within three years, that they will meet US Tier II Bin 5 emissions requirements and that there are plans to include it on V6 and inline 4 engines. A spokesperson from Honda has also said that it is “likely” that the clean diesel technology will come to Europe and that if the European Commission’s NOx emission standard of 0.2 g/km is adopted, it should meet any proposed Euro 5 regulations.
Elsewhere...
Honda is trialling its new advanced V-Tec engine on an Accord in Japan, where the engine is to be evaluated before a decision is made on whether to bring the technology to Europe. At present, there are no plans to introduce the variable valve timing and lift electronic control system to Europe.
The new engine allows “optimum” control over intake valve lift and phase depending on engine speed and load, resulting in improved charging efficiency – how well the engine “breathes” – for an increase in torque at all engine speeds. Under low to medium load levels, the valves are set for low lift and early closure, which results in the reduction of pumping losses and improved fuel economy.
Intake components in the engine have also been improved, and in conjunction with the valve timing, Honda calculates that fuel economy can be improved by around 13 per cent compared to the current production 2.4-litre i-VTec engine.
Honda plans to release a production vehicle equipped with the new engine within three years, with spokesmen stating that although the engine was tested on an Accord, the technology is potentially applicable to “various” platforms.