Emissions From Marine Engines

The term “preventing air pollution" is an absolute put off for anyone who is looking for a topic to debate on, or in this case, planning to write an article about. But why is this refrain from the topic? Why is it that the moment you see the word “air pollution” on screen you turn off the window? The mistake is not yours, this is probably because since the time we were toddler we have been hearing this term and we often ask “What’s the fuss all about?”

Well, we know the basic stuff how carbon dioxide causes pollution and so on and so forth. But the question is, if “air pollution” is the matter of such grave concern and has been a hot topic for debate for past so many years then why don’t we see any progress?

“Air pollution” is something like “once the damage is done, it’s done.” Means, we cannot mitigate the amount of pollution already in air but what we can do is take precautions to prevent pollution from proliferating in future. Probably many know all these and they all know that in this world of competition hardly anyone cares about the pollution aspect, unless they are forced to.

But the problem is much deeper when it comes to air pollution caused by marine vehicles and the worst part is there is nothing that can be drastically done about it. Let’s try to trace the factors resulting air pollution by marine diesel engines, the makers behind marine air pollution and why marine air pollution is considered dirtiest of them all?

It is an undisputable fact that marine diesel engines contribute significantly to air pollution that damages the environment as well as harm public health.

But why is it that marine air pollution is always the hot topic of discussion and how it is propagating air pollution so significantly?

A simple answer to this question is because marine diesel engines burn the lowest grade diesel fuel. Diesel engines are used widely as power sources primarily due their high thermal efficiency, high fuel economy and durable performance but in the process emit large quantity of toxic gases and solid substances which significantly pollute air.

The marine diesel engine toxic emissions mainly consists of the following components

• Smog
• Particulate matter
• Global warming gases

Let us find out about each of these components one at a time as follows.

Nitrogen oxide (NOx)

NOx is formed when nitrogen combines with oxygen inside the extremely hot and highly pressurised chambers of diesel engines. This NOx combines with hydro carbons in the atmosphere forming ozone which produces smog. Now ozone is good when it is high in the stratosphere, where it protects earth from the ultraviolet rays of the sun. But when it is dangerously low in the atmosphere it traps heat and affects human health.

Sulphur dioxide (SOx)

SOx is formed when unburned fuel in diesel engines produces small particles of sulphur and carbon which together contribute to smog. SOx is directly related to the sulphur content in fuel which when combined with water vapour results in acid rain.

Chloro floro carbons (CFC’s)

Emissions of CFCs from the world shipping fleet was estimated at 3,000-6,000 tons - approximately 1 to 3 percent of yearly global emissions. Halon emissions from shipping were put at 300 to 400 tons, or around 10 percent of world total.

Particulate matter consists of tiny solid particles and liquid droplets which are consist of soot, dust, salt, acid and metals that are invisible to human eye but appears as cloud or fog like haze. These particles are less than 10 microns in diameter and one seventh the thickness of human hair. Diesel contains 60 to 200 times more small particles than gasoline engine exhaust.

Gobal warming gases includes methane, nitrogen oxide and the main culprit, carbon dioxide. All these are produced from the burning of fossil fuels. These gases when in atmosphere trap heat and cause global warming and climate change. It has been predicated that global warming will lead to dilapidated environmental concerns in near future if adequate steps to reduce emission of toxic gases is not taken.

In the next article we will see what are the regulations and the steps that needs to be taken to reduce emissions from marine diesel engines such as cold ironing techniques.

^References

^{Marine diesel engines and air pollution : Blue water networks}

^{www.nescaum.org}

^{www.earthscape.org}