Diesel Oxidation Catalysts (DOC)

We recently spent time at a well known eco-friendly game ranch in Northern Kenya. I was interested to see just how many vehicles were running around. It got me thinking about the environment and the pollutants we were spilling out into this beautiful pristine environment and what the animals were having to breathe in as we were passing.

It’s all well and good having an ‘eco friendly” lodge but if the vehicles being used to transport the tourist are spewing harmful toxins into the environment just how eco friendly are these lodges?

If humans are concerned by breathing diesel fumes continuously, how are the wild animals effected and what would the long term effects of breathing these diesel fumes daily from the many tour buses that visit these destinations. Is it time to limit the number of vehicles surrounding the animals or is the answer in the fitment of DOCS on all the vehicles? So I decided to do some research on the web. This is what I found out:

What are Diesel Oxidation Catalysts (DOC)

We know diesel engines offer better fuel economy, long-term reliability and lower fuel emissions than petrol engines. However, there are concerns about the environmental and health hazards posed especially by diesel exhaust emissions.

Diesel emissions are an important topic for catalyst development. Sales growth of diesel cars has raised concern on the possible health effects from the ultra-fine particulates in diesel emissions. All new diesel – engine cars sold in Europe are now fitted with oxidation catalysts.

Diesel Oxidation Catalysts lower particulate mass by up to 50%, by destruction of the organic fraction of the particulate, as well as making significant reductions in CO, HC and the characteristic diesel odour. However, the number of particles is unchanged and issues associated with the effects of ultra-fine particulates remain unresolved.

Here are some Q & A from the web site http://www.epa.gov/otaq/retrofit/documents/f03016.pdf

Technical Highlights
United States Environmental Protection Agency, Air and Radiation EPA420-F-03-016
June 2003, Office of Transportation and Air Quality

Questions and Answers on Using a Diesel Oxidation Catalyst in Diesel Trucks and Buses

The pollution emitted by diesel engines contributes greatly to our nation’s air quality problems. Even with more stringent heavy-duty highway engine standards set to take effect in 2004 and 2007, existing trucks and buses will continue to emit large amounts of nitrogen oxides (NOx) and particulate matter (PM), both of which contribute to serious public health problems in the United States. Fortunately, there are several techniques and technologies designed to reduce diesel pollution from existing trucks and buses. Using pollution control devices such as a diesel oxidation catalyst (DOC) is one way existing engines can be upgraded (or “retrofitted”) to pollute less. This fact sheet discusses diesel oxidation catalysts.


What are the health and environmental effects of diesel exhaust?
Heavy-duty trucks and buses account for about one-third of NOx emissions and one-quarter of PM emissions from mobile sources. In some urban areas, the contribution is even greater. The fine particles in diesel exhaust (known as particulate matter) can penetrate deep into the lungs
and pose serious health risks including aggravated asthma, lung damage, and other serious health problems. In addition, diesel exhaust is a likely human carcinogen. Children are more susceptible to air pollution than healthy adults because their respiratory systems are still developing and they have a faster breathing rate.

Diesel exhaust also has environmental impacts. PM from diesel engines contribute to haze, which restricts visibility. In addition, diesel exhaust contributes to ozone formation (a component of smog), acid rain, and global climate change.

What is a Diesel Oxidation Catalyst?
A DOC is a device that uses a chemical process to break down pollutants in the exhaust stream into less harmful components. More specifically, it is a physical device with a porous ceramic honeycomb-like structure that is coated with a material that catalyzes a chemical reaction to reduce pollution.

What are the benefits of a DOC retrofit?
DOCs reduce emissions of particulate matter by at least 20 percent. DOCs also reduce emissions of hydrocarbons by 50 percent and carbon monoxide by 40 percent.

Does the EPA verify these emission reductions?
Yes, EPA evaluates the emission reduction performance of retrofit technologies such as DOCs, including their durability, and identifies engine operating criteria and conditions that must exist for these technologies to achieve those reductions. For a list of DOCs and other technologies that
EPA has verified, visit: www.epa.gov/otaq/retrofit/retroverifiedlist.htm. For more information about EPA’s verification process, visit: www.epa.gov/otaq/retrofit/retrofittech.htm.

How much does a DOC cost?
DOCs for school buses cost about $1,000 - $2,000. Field experience suggests DOCs take about 1-3 hours to install.

What type of fuel does a DOC require?
DOCs can be used with regular diesel fuel, but the effectiveness of a DOC may be increased with the use of ultra low sulfur diesel (ULSD – 15 parts per million sulfur). Currently, ULSD costs between 8 and 25 cents per gallon more than regular diesel. ULSD is available in many
parts of the country now and will be available nationwide beginning in June 2006.

Can a DOC be used on any engine?
Yes. DOCs have been used for years on a variety of diesel vehicles including trucks, buses and construction equipment.

Are there special maintenance requirements for a DOC?
No. Much like a catalytic converter on a car, once a DOC is installed, it rarely requires maintenance.

How long does a DOC last?
Most DOCs come with a 100,000 to 150,000 mile warranty, and can last 7 to 15 years.
Where can I get a DOC?
For more information about manufacturers of DOCs or other retrofit equipment visit our Web site at: www.epa.gov/otaq/retrofit/cont_retromfrs.htm.

Where can I find more information?
For more information on these topics, please visit these EPA Web sites:
• Voluntary Diesel Retrofit Program: www.epa.gov/otaq/retrofit
• Clean School Bus USA – Basic Information on Retrofit Options:
www.epa.gov/otaq/schoolbus/retrofit.htm
• Clean Diesel Independent Review Panel: www.epa.gov/air/caaac/
clean_diesel.html
• Health Assessment Document for Diesel Engine Exhaust: http://
cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=29060

You can also contact the Office of Transportation and Air Quality library
for document information at:

U.S. Environmental Protection Agency
OTAQ Library
2000 Traverwood Drive
Ann Arbor, MI 48105
Phone: 734-214-4311
Email: GroupAALibrary

Rant About Matatus!

Yesterday, I saw a matatu cut down the inside of all the traffic splashing all the pedestrians on the side of the road, while forcing them off the roadside into the gutter. Then the driver proceeded to cut me off and then pushed his way into the queue. When one motorist tried to talk to him, he just turned up his music louder to drown out the criticism. Then he pulled out and proceeded to overtake down the wrong side of the road, again forcing oncoming traffic off the road.

When the matatu got to the junction he then turned right in front of a Minister's car, cutting him off and forcing the Minister's driver to brake very hard to avoid hitting him! Meanwhile, a policeman at the junction watched the whole saga and never pulled the Matau over, nor did the Minister's car make any attempt to do anything. This is normal operating procedure for matatus and everyone is fed up, yet they get away with it day in and day out.

I don't understand why the police don't do something to stop these maniacs. If a regular driver is seen by a policeman committing even the most minor misdemeanour they are immediately pulled over, chastised, taken to court, etc., while the matatus, the real killers, are left to wreak havoc on Kenya's roads. It just doesn't make sense to me.

The arrogance of the matatu drivers is becoming world renown, with overseas tourist talking about them before they even get here. Is this the impression of our country we want to send to foreign visitors? Do we want them to be stunned by Kenya’s beauty and wildlife only to have it tarnished by these dangerous, arrogant drivers?

Fond Memories

Fond memories

One of the best moments in my life was when I spent a day with my son Craig and some of his mates taking them all for rides in my rally car.

We took them out to a ‘test session' about 30 minutes driver from Nairobi. They watched as we tested the car. Afterwards, we then spent a few hours taking each child in the rally car for a run on the test roads. They loved it and we all had a ball.

The Importance of Driver Training

So the death toll in Kenya for road related deaths has already reached 130, and we are only just past the first month of the new year.

These deaths could have been avoided if drivers only had proper training. We are losing lives at a rapid rate on Kenyans roads. One person dies every 3 hours due to road related injuries in Kenya. That equals 3,000 deaths a year.

It's important that managers of companies wake up to this fact and do it urgently. Companies can no longer incur losses incurred because of bad driving - especially in this current global economic turmoil. It's not only a moral issue of saving lives, but it will also bite into the company's bottom line and affect much needed profits.

We encourage all employees to petition their companies to pay for professional defensive driving lessons. It could save your life.

Free Wheeling - Beware!!

The term "Free-wheeling" describes a vehicle traveling in neutral or with the clutch depressed.
Many drivers use freewheeling in a effort to save fuel and is common practice with many truck drivers.

By putting the vehicle in neutral and allowing it to free wheel down a hill, can cause problems when it’s time to re-engage the gear. For example, when the gear is forced in, it can damage the transmission or result in locking the wheels and causing the vehicle to skid out of control.
Freewheeling vehicles rely on the brakes to slow them down resulting in overheating the brakes, and boiled brake fluids. Therefore when heavy braking is needed, brakes will tend to fade, and give a "long pedal" causing inefficient and longer stopping distances.

Many drivers will also push the clutch in conjunction with the brake during an emergency stop. By doing this they disengaging the engine from the drive train causing a loss in engine braking efficiency.

In addition, coasting down hills compromises engine compression braking, and descending steep or slippery hills should be negotiated with the use of engine and foot brake balanced so as not to over work each system.