Diesel fuel actually cheaper than unleaded again here

Cheaper diesel prices are a good thing for our sailboat. I used almost 15 gallons last year. Another year like that and I could be financially ruined.

Tom

 

Don't forget 2,3,7,8 tetrachlorodibenzo-penta-dioxin. Diesel exhaust is a proven source of 2,3,7,8 TCDD. This particular dioxin was made famous over the use of Agent Orange in Vietnam

Note: everybody in North America was exposed to 2,3,7,8 TCDD. Agent Orange was used in North America as well. It was sold by Dow as Esteron Brush Killer, which contained 2,4 dichlorophenoxyacetic acid and 2,4,5 trichlorophenoxyacetic acid

The 2,3,7,8 TCDD wasn't added on purpose. It is a common byproduct in production of 2,4,5 T

Because the vast majority of pickup truck owners *might* at some point hitch up a heavy trailer. Of course, the vast majority of pickup trucks must struggle under the weight of a driver and a couple of bags of groceries

Actually, there are a lot of ignorant hillbilly redneck tools out there who think it's COOL to have their diesel pickup blow giant clouds of black smoke

They remove the DPF from the exhaust system. They even order a custom tuner box to produce black smoke ON COMMAND. Yee Haw!!

Naturally, these numnuts are allowed to vote and even breed

 

OMG vote is one thing but reproduction?

there need to be new laws in place in the US

 

All diesel vehicles sold in the US after 2007 meet the same emission requirements as gasoline vehicles. No 2009 diesel vehicle in the US (including tractor trailers (lorries)) will "blow smoke" as they come from the factory. As Jayman said, some people illegally modify their vehicles.

Does the 2009 Jetta TDI put out more NOx than a 2009 Prus? Yes, it does. It puts out less than some other gasoline vehicles. All diesel vehicles sold in the US will put out less pollutants, including NOx, than new 2009 motorcycles. Even my 2003 diesel with no NOx Catalyst puts out less pollution than a new motorcycle or scooter.

I care about reducing our dependence on oil and specifically imported oil. Any vehicle that moves us in that direction is OK with me as long as to meets federal standards for emissions. I would prefer someone drive a 40 mpg Jetta diesel than a 25 mpg gasoline Jetta.


Jayman: Diesels may very well put out the chemical you claim. Gasoline and Diesel vehicles put of dozens of chemicals. The EPA and CARB choose to regulate 5.

 

The issue with diesel emissions has become a non-issue with the new "clean diesel" vehicles currently being produced. The overall difference between diesel and gas has become trivial. Higher NOx emissions are offset by lower HC emissions. PM emissions have been essentially eliminated with DPF.

As far as PCDD emissions are concerned, EPA estimated that PCDD emissions from ALL diesel sources (on-road and off-road) was only about one percent in 1995 (EPA Final Regulatory Impact Analysis: Control of Emissions From Nonroad Diesel Engine). That would have pre-dated used of DPF. Since PCDD would partition to the solid (particle) phase in a combustion process, a DPF would capture what little PCDD is formed in the exhaust, making this a non-issue as well.

The concern expressed by some here about increased diesel LDV penetration is not justified from an air quality perspective.

 

I don't doubt your knowledge of the subject, but could you explain or at least spell out the acronyms? NOx...HC...PCDD. DPF...LDV...I'm lost. Reminds me of when I was trying to explain old PC terms to people who didn't know what a cursor was. I'd appreciate it.

 

Yup - sorry.

NOx = oxides of nitrogen (NOx = NO (nitric oxide) + NO2 (nitrogen dioxide)).

HC = hydrocarbons. Refered to as NMHC (non-methane hydrocarbons) or NMOG (non-methane organic gases) by regulators.

PCDD = polychlorinated dibenzodioxins (family of dioxins that includes 2,3,7,8 tetrachlorodibenzo(p)dioxin (2,3,7,8 TCDD) which is what jayman was referring to).

DPF = diesel particulate filter.

LDV = light-duty vehicles.

 

NOx = Nitrogen Oxides
HC = Hydrocarbons
PCDD = ???
DPF = Diesel Particulate Filter
LDV = Light Duty Vehicle


NOx: Nitrogen Oxides generally increase with the compression ratio of an engine. Diesel engines have very high compression ratios compared to gasoline engines and generally produce more NOx. However turbocharged gasoline engines also have relatively high NOx emissions compared to most low-compression gasoline engines

HC: Most hydrocarbons are not released from a vehicle's exhaust but from the gas tank or in the fuel distribution system. Those visible vapors coming out of your gas tank when you fill up are hydrocarbons. Gasoline is a lighter fuel than diesel and is evaporates as a much faster rate. That is why the ground around a diesel pump is oily. What you see is diesel fuel that hasn't evaporated. On the other hand if you spill gasoline on a concrete surface it will evaporate in minutes.

DPF: Diesel particulate filters are mandatory to meet current emission requirements is the US. The filter captured soot from the exhaust, stores it, and then periodically burns it. DPF's are also mandatory on all heavy duty trucks which is why new tractor trailers don't belch black smoke every time they accelerate. Gasoline engines currently are not checked for PM (Particulate or soot) emission. However, DI (direct injection) leads to PM formulation. For this reason starting the fall, the European Union will require all direct injected engines to meet PM limits.

In general diesel and gasoline engines emit different types of pollution. Diesel produce more NOx and PM while gasoline vehicle emit more CO (Carbon Monoxide) and HC. This can be seen by comparing two similar Volkswagen engines available in the EU.

------------------ 1.4L TSI (140PS) --------------- 2.0L TDI (140PS)
Fuel ----------------- Gasoline ------------------------ Diesel
Horsepower ----------- 140 ---------------------------- 140
Injection --------------- DI ------------------------------ DI
Aspiration ------ Turbo + Supercharger ------------- Turbo
Emissions
CO --------------------- 0.377 g/km ------------------ 0.084 g/km
NOx ------------------- 0.036 g/km ------------------- 0.197 g/km
HC --------------------- 0.085 g/km ------------------ 0.027 g/km
PM -------------------- Not Tested -------------------- 0.018 g/km

 

There are laws, but they are easily ignored. Only a handful of states require yearly I/M programs for emissions and safety. The "tuner box" I mentioned is plugged into the truck, and can be easily unplugged

 

There are various studies from the EPA, it's helpful to cite sources. Such as this one

EPA NCEA - On-road Sampling Of Diesel Engine Emissions Of Polychlorinated Dibenzo-p-dioxin And Polychlorinated Dibenzofuran

Which claimed the exhaust stream of a non-DPF heavy duty truck had significant PCDD yield

One thing EPA did do was tightly regulate the biggest source of airborne dioxin, municipal incineration. With this source now tightly controlled, the remaining source of PCDD ranges from woodstoves to diesel vehicles

THis is one of the highly detailed reports available from the EPA

Comparison of the Carcinogenicity of Diesel Exhaust and Carbon Black in Rat Lungs| Research Project Database | NCER | ORD | US EPA

I have to warn the reader the following document is long and very technical

http://www.epa.gov/ttn/atw/dieselfinal.pdf

The use of a DOC/DPF

Investigations on the effect of chlorine in lubricating oil and the presence of a diesel oxidation catalyst on PCDD/F releases from an internal combustion engine.

has been shown to *reduce* the level of PCDD, but NOT eliminate it. See above comments on diesel exhaust, and the "little" PCDD it produces. The EPA confirmed that diesel engines without DOC/DPF are potent point sources of PCDD

What I find interesting is that after you tack on the DOC/DPF and - for 2010 - urea injection, the fuel economy goes down, the unit cost goes up, to the point a LD diesel is a hard sell compared to a hybrid

 

I did - the RIA. Specifically section 2.2.2.7 Dioxins...

The url is http://epa.gov/nonroad-diesel/2004fr/420r04007c.pdf if you want to verify but this too is a rather large pdf file.

Is EPA issuing conflicting data in its technical documents?

 

If the source of chlorine for PCDD formation comes from the engine lub oil, then the PCDD emissions wouldn't be unique to diesel engines. Since gas engines don't currently use particulate filters, the question becomes are they a larger emitter of PCDD than DOC/DPF diesels?

 

oeps

 

those diesel DPF collect and then HIGH temp burn them up.

is that also the way the US DPF work....

wel in that case those DPF here are no longer supported because a LAB discovered that when you HIGH temp burn the particuls in that filter you even get smaller particals that can be even more of a health risk.

so tax credit on putting a aftermarket DPD on a diesel is no longer and the law for DPF in new cars is now under discussion if i am correct.

 

No, it is not

That study you cite is from 2004, concerning non-road diesel engine rules. By non-road, the EPA determines things such as stationary generators, tractors, locomotives, etc.

To quote another section, pdf page 77, from the same article you cited

"Also, a supplemental paper provides more detail on nonroad diesel exhaust.194 In addition, a paper published by the Society of Automotive Engineers gives future projections to 2007 for these air toxics.195 These references form the basis for much of what will be discussed in this section.
Figure 2.2.2-1 summarizes the contribution of nonroad engines to average nationwide lifetime upper bound cancer risk from outdoor sources in the 1996 NATA. These data do not include the cancer risk from diesel PM since EPA does not presently have a potency for diesel particulate/exhaust. Figure 2.2.2-2 depicts the nonroad engine contribution to average nationwide inhalation exposure for benzene, 1,3-butadiene, formaldehyde, acetaldehyde, and acrolein. These compounds are all known or suspected human carcinogens, except for acrolein, which has serious noncancer health effects. All of these compounds were identified as national or regional risk drivers in the 1996 NATA, and mobile sources contribute significantly to total
emissions in NATA. As indicated previously, NATA exposure and risk estimates are based on air dispersion modeling using the ASPEN model. Comparisons of the predicted concentrations from the model to monitor data indicate good agreement for benzene, where the ratio of median modeled concentrations to monitor values is 0.92, and results are within a factor of two at almost 90 percent of monitors.196 Comparisons with aldehydes indicate significantly lower modeled concentrations than monitor values. Comparisons with 1,3-butadiene have not been done.
Previously, extensive work was done on gaseous air toxic emissions including those from nonroad diesel and reported in EPA’s 1993 Motor Vehicle-Related Air Toxics Study.197 This final rule will reduce these emissions. Dioxin and some POM compounds have also been identified as probable human carcinogens and are emitted by mobile sources, although nonroad sources are less than 1% of total emissions for these compounds."

In the context of current rules for non-road diesel engines, they are a minor contributor to overall dioxin in air quality measurements. The previous major source of such emissions were incinerators, which are now highly regulated with respect to such emissions

Ironically, since the overall dioxin air production appears to have declined, what used to be a minor source of dioxin - onroad diesel engines - have shifted to being a significant contributor

 

If you care to read the entire article, and not the online brief, the authors concluded that chlorine in engine oil is *not* a statistical contributor to PCDD formation in vehicle exhaust

 

Part of that issue is that rushing a regulation into effect - without consideration of all the long term effects - can introduce new or unforeseen problems that may be just as serious as the problem they attempted to resolve

 

Thank you and to JSH for the information.

 

That can be a real problem. It ends up like trying to swat a fast moving fly, with each swing producing another piece of legislation.

Tom

 

Yes, DPF collect particulates and burn them to reduce particulate count and make them smaller.

However, you act as if gasoline vehicles don't emit PM. Just because EU and US regulators don't test gasoline cars for PM doesn't mean they don't produce PM. Gasoline cars produce at lot of PM and this PM is the very small particles that you are complaining about.

http://www.healthyhome.com/files/Documents/Gasoline cars may need particulate filters.pdf
http://www.epa.gov/ttn/chief/conference/ei13/mobile/baldauf_pres.pdf

Per the EPA test:
2020 Mobile Source Direct 2.5 PM
Non-Road Gasoline ---------------- 24%
Commercial Marine Diesel -------- 23%
Highway Gasoline Vehicles ------- 16%
Non-Road Diesel ------------------ 16%
Aircraft ----------------------------- 9%
Highway Diesel -------------------- 6%
Locomotives ----------------------- 5%

At least the EU recognized this problem and beginning with Euro 5 will start testing gasoline cars for PM. What will you do in 6 months when EU tests show that gasoline cars produce as much PM as diesels?