Growing pressure to reduce harmful exhaust gas emissions has lead to a substantial amount of research in this area over the previous three decades or so. Generally, these efforts can be divided into two categories:
In-cylinder technologies
These aim to improve the combustion process inside the engine. Attention is focused on injection timing and duration, fuel atomisation, valve timing, turbocharger settings and regulating the temperature inside the combustion chamber. Major reductions in engine-out emissions have been achieved through this work, but as with any such endeavour the law of diminishing returns applies. Compression-ignition engines have also thrown up a couple of paradoxes for the emissions engineer. Firstly, whatever is done to reduce emissions of diesel particulate matter tends to increase oxides of nitrogen and vice versa. Secondly, whilst diesel particulate matter emissions by mass have been significantly reduced, the actual number of very small particles emitted is more difficult to control, and it is these which are of most concern to health professionals.
Exhaust gas aftertreatment
Even taking account of recent advances, the zero-emission internal combustion engine is not yet reality, and probably never will be. Virtually no on-highway engines would be capable of meeting the rigorous emissions limits now in force if they were judged on engine-out emissions.
Exhaust gas aftertreatment is the field of technology devoted to reducing harmful exhaust emissions after they have left the combustion chamber, but before they enter the environment. This is the area in which Blackthorn has built an exceptional capability since it was founded in 1996. We are specialists in catalytic converters and diesel particle filters, and further in-depth information on these is available by clicking on the links.
