Focus Shift: NOx Emissions and Why the World Needs to Pay Immediate Attention
Marine vessels release different kinds of harmful emissions (SOx, NOx, and particulate matter) into the air which have severe side effects on the environment and on human health. The demands of the thriving logistics and marine industries drive the need for more marine vessels, so it is essential to ensure safeguards to limit its impact on the environment. In an effort to curb the harmful impacts of these enormous global industries, the International Maritime Organization (IMO) has released strict guidelines on emissions released from marine vessels. The stringent regulations have forced the industry to re-invent ways to tackle emissions.
Understanding the environmental impacts of NOx
In the third IMO greenhouse gas study, the Marine Environment Protection Committee (MEPC) argued that shipping contributes to 15% of the global nitrogen oxides (NOx) emissions. Unlike Sulphur oxides (SOx), NOx gases are not generated as a direct derivate of the fuel burned, but by the process of burning the fuel. NOx forms when nitrogen reacts with oxygen at high combustion temperatures. The major impact of it entering the environmental ecosystem is that it catalyzes the breakdown of ozone. NOx reacts with other substances and therefore plays a role in forming smog, acid rain, ground-level ozone, and increased levels of fine particles (PM), which are associated with deforestation, surface water acidification, reduced crop yield, and adverse health effects. Health effects are mostly related to the human respiratory system causing inflammation of the airway, respiratory diseases, and increased sensitization to allergens.
Too much focus and regulatory limits applied in the U.S. on NOx already, and very little restrictions applied to reduce the other compounds that mix with NOx to produce smog; i.e. VOCs. We do this in an attempt to force the trucking industry to bear the brunt of the costs to reduce smog and pass those cost to us indirectly. Just my 2 cents, but evidenced by our super restrictive limits on NOx levels for diesel engines as compared to other countries except Japan and Canada who also put the onus on diesel engine oem's to fix smog with these "fuel neutral" policies. This also explains why a diesel powered 3/4 ton pickup may cost eleven grand more than an equivalent gas powered pickup in the U.S. The exhaust treatment systems must be massive, complex, and very expensive to meet emission compliance.