Why Diesel Oxidation Catalysts (DOC) Succeeds? Increasing number of Vehicles behind Pollution

Pollution, pollution, everywhere! With every passing day, as the number of vehicles increases on the roads, it seems that this social issue will never be taken care of!

Do you know that the heavy-duty trucks and buses account for about one-third of NOx emissions and one-quarter of PM emissions from mobile sources? Yes, it’s true!

Air Pollution and Human Health

Although in the present day, the government has imposed strict standards for the heavy-duty diesel vehicles, some existing trucks and buses still emit harmful gases that contribute to extremely serious health issues such as asthma & lung damage.

And, all this is because of the diesel exhaust released from the diesel vehicles that penetrates deeper into our lungs and affects our health. Children as compared to adults are more vulnerable to air pollution since their respiratory systems are still in the developing phase.

Solution to Pollution

But, as they say, where there’s a will, there’s a way, and so, there is hope for pollution too! With the advancement in technology, the device to reduce the pollutants (unwanted bi-product of older, diesel-fueled heavy duty vehicles) has become no less than a blessing to humankind.

Here, we are talking about diesel oxidation catalyst. This pollution controlling device is beneficial for upgrading a diesel engine to make the atmosphere less polluted.

What exactly is DOC?


Example of RoadWarrior DOC

A DOC is a pollutant reduction device that utilises a chemical procedure to break down pollutants in the exhaust stream into less injurious components. It consists of a stainless steel canister that contains a ceramic honeycomb-like structure called a substrate coated with a material that causes a chemical reaction to control pollution.

DOC- The solution for every diesel vehicle

In the case of diesel exhaust, the catalyst oxidises carbon monoxide, gaseous hydrocarbons, and unburned fuel and oil absorbed on the carbon particles. The unburned fuel and oil are called soluble organic fraction, and can make up a crucial part of the particulate matter.

A flow through oxidation catalytic converter installed on a vehicle can control the soluble organic fraction (containing harmful chemical pollutants) of the particulate by almost 90%. Not only this, but it also eliminates the detestable odour of diesel exhaust. It also reduces carbon monoxide and gaseous hydrocarbons emissions, from 60% to 90%.

Whether it is on-road sectors or non-road, DOC has become one of the most successful strategies to control pollution all around the world.

How DOC works with DPF to reduce emissions from a diesel engine?

Catalytic generation of NO2 more toxic than NO


Catalytic generation of NO2 can create air quality issues in some applications. Because of the thermodynamic equilibrium of reaction, reached in the atmosphere after a while, regardless of the original composition of NOx, the oxidation of NO tends to be of less concern in most surface applications. Nitrogen dioxide can be effectively used for the regeneration of diesel particulate filters (DPF).


Source : Doosan

In today’s diesel emission control systems, often DOCs are specifically designed for high NO2 production to support the operation of DPF systems.

Need DOC cleaning?

Do you know that after all the magical work that DOC performs, regarding pollution control, it even needs cleaning just like your DPF?

Yes, it’s a must!

And who do you look up to for DOC cleaning? Look no further than Re-Flow Filter Cleaning Solutions.

Re-Flow offers DOC cleaning for medium and heavy-duty diesel engines. With Re-Flow, you can be sure of your DOC units to be baked, cleaned, flowed, tested and inspected. We are your Diesel Oxidation Catalyst Specialist. Get in touch now!

Posted in DPF & DOC.