quote:

---

Originally posted by WannaWagon:
Found this AP writeup on your trip today. ..
http://www.enn.com/news/2004-06-24/s_25117.asp

Except, what is the deal with the comments by NRDC in this article? Where are they getting their info on biofuels? Seems to me their position on biodiesel is ill-informed and really out of step with the rest of the enviro community.

---

Comment made by NRDC reads "Environmentalists give biodiesel mixed reviews. While biodiesel produces fewer greenhouse gases than gasoline, it releases more smog-forming pollutants, said Diane Bailey, a diesel expert at the Natural Resources Defense Council (NRDC).

Bailey supports the use of 100 percent biodiesel for people who already drive diesel vehicles, but she doesn't see vegetable oil as a long-term solution to cleaning the air, despite the couple's successful road trip".


There statement about more smog-forming pollution in the article makes no since to me either. Sooooo I wrote them a letter.

Dear Diane Baily and other members of NRDC, The following is a Diane Bailey quote; Diane is said to be a member of your organization. The quote is from this article; ]http://www.enn.com/news/2004-06-24/s_25117.asp

"While biodiesel produces fewer greenhouse gases than gasoline, it releases more smog-forming pollutants", said Diane Bailey, a diesel expert at the Natural Resources Defense Council (NRDC).

Please let me know if you feel this is a misquote. If you feel this is not a misquote please provide some documentation to support your statements. This information is completely contradictory to all I have read on the topics of vegetable oil fuels. Maybe I've missed some studies so any information you provide I would certainly appreciate.

A timely response would be appreciated,
George Jessup
Director GP Inc.

Was I premature in sending this? As in, do I remember what I've read wrong? If not; and you want to send them a message too here is their web site contact page.
http://www.nrdc.org/contactUs/

As far as I am aware, the only emission which is increased by using biodiesel is NOx, and that can be minimised by minor injection timing adjustments.
There are some concerns on WVO emissions, but this one report has not been suported by any other study so far.

a letter we sent to Diane Bailey at Natural Resource Defense Council:


We're david and mali, the veggie oil/biodiesel travellers who drove down to Argentina.

The AP guy quoted you in his pretty lame article about our trip. I know he totally slanted the article away from anything that WE were interested in having printed, so I imagine that he did the same with his quote of the NRDC about biofuels.

We just want to check with you all, though. We think it's a bad idea to go slagging biodiesel, biofuels in general.

The only bad thing that biodiesel produces that is equivelant to regular diesel engines is NOx, and with a tiny bit of modification and more research that could be eliminated in biodiesel-using engines.

To us, in your quote, you came across as being a shill for big money corporations who are promising us electric vehicles (keep waiting), hybrid vehicles ($25K plus, and they still get less MPG than a 1979 economy car), and hydrogen technology (keep waiting).

We can't afford to Keep Waiting. We HAVE to reduce consumption. But at the same time, we have to use the already-existing buses, trucks, and cars in the most efficient and environmental manner possible, and of course, as you should say, this is with the use of biofuels.

Especially we needed to say this to folks all along our trip, in Mexico, nicaragua, bolivia, etc., when do you think THEY are going to get a hybrid car!!! They produce lots of oilseeds, and with some good planning and stuff, could produce their own biofuels and tinker with their engines to make them produce less NOx.
They wouldn't have to be dependent on Big Oil or North American technology which Never Comes Along.

You must agree that within the context of a
transformation of consumption and reduction in use of motor vehicles, as well as improvement of engines and development of cleaner-burner technology, there exists a very important place for the use of biodiesel.

We think you all need to be a bit more careful around reporters who are looking for a little piece of information to use to "write their own story."

Thanks,

david, mali, emilio

quote:

---

Originally posted by jeepin, moggin Jessup:
... Sooooo I wrote them a letter.

Dear Diane Baily and other members of NRDC...

Was I premature in sending this? As in, do I remember what I've read wrong? If not; and you want to send them a message too here is their web site contact page.
http://www.nrdc.org/contactUs/

---

Well they replied back with the below info. Sounds. To educate ourselfs (and them) can we take a look at what they say below and verify its accuracy?

quote:

---

Dear George,

Thank you for writing to NRDC and for your interest in biodiesel. While we truly admire biodiesel users, NRDC staff have reservations over all kinds of biodiesel, elaborated on more in the factsheet I attached to this e-mail.
In brief:

a) It's prone to being massively diluted ("blended") by regular dirty diesel.
b) There's not enough of a feedstock supply to make a big dent in overall diesel use in the US.
c) Some feedstocks, particularly farmed oils, can have serious negative impacts to the environment. Consider the use of GMOs, pesticides, fertilizers and polluting diesel equipment in farming those oils, plus other environmental problems related to farming: Erosion, mono-crops, etc.

Given the above issues, we don't support biodiesel as a feasible solution to the problems caused by diesel. Instead, NRDC advocates for it in it's pure form in certain niches: marine, remote locations, and exceptionally responsible passenger car owners.

Again, thanks for contacting NRDC and for your interest in our work.

Sincerely,
Alexandra Hernandez
NRDC Membership and Public Education
www.nrdc.org

---

This message has been edited. Last edited by: jeepin, moggin Jessup (coachgeo),

This is the fact sheet that is the synopsis of why they think as they do.

[i]October 2002
NRDC Backgrounder
Biodiesel: Cleaner But Not Necessarily Clean Enough


Biodiesel, in its 100% pure form, is a relatively non-toxic, biodegradable, renewable fuel that burns much more cleanly than regular diesel and works in almost any diesel engine. Unfortunately, biodiesel is usually blended with 80% standard diesel fuel and only 20% “bio” fuel, which drastically reduces its environmental benefits. In some cases, biodiesel contains as little as 2% “bio” fuel, yielding negligible air quality benefits, yet allowing for ‘greenwashing’ by fleets that use it to avoid using cleaner alternative fuels (like natural gas) or advanced technologies (like hybrid-electrics). Pure biodiesel has a role in the movement toward cleaner fuels, particularly in boats and farm equipment. However, biodiesel is not a promising replacement for advanced technologies and alternative fuels in centrally-fueled urban fleet vehicles, such as transit and school buses, nor is it a substitute for using the most advanced emission controls to reduce particulate matter and other pollutants from most other diesel engines.

Biodiesel can be made from many feedstocks. Biodiesel is processed from vegetable oils, fats or greases, including used grease, such as waste from deep-fat fryers at McDonalds.
.It comes in different blends: ure, 100% natural oil based biodiesel is termed “Neat” or B100.
· B20, much more common than B100, is only 20% biodiesel and 80% regular diesel.
· A 2% biodiesel blend is also used often to add lubricity (greasiness) to reduce engine wear and tear.

Most biodiesel was made from recycled restaurant grease and unused animal fat until a 1999 soy oil subsidy made soy the largest source.1 Current waste grease and inedible animal tallow supplies are enough to produce almost one billion gallons of biodiesel,1 and U.S. soy production is enough to produce almost 2 billion gallons of biodiesel.2 However, this is only a fraction of the over 36 billion gallons of diesel sold in 2000 throughout the U.S.3

Cooking oils, such as soy, canola, tallow, mustard, restaurant greases, etc. are processed to remove the fatty acids with methanol and a catalyst.4 The byproduct is glycerine (commonly used in soap). Roughly one bushel of soybeans produces 1.5 gallons of biodiesel.

Biodiesel fuel is only as clean as the amount of the “bio” in the blended fuel.
An evaluation of potential health effects and emissions by the Southwest Research Institute showed that pure biodiesel may reduce exposure to cancer-causing contaminants by over 90% compared to regular diesel.5 But when B20 biodiesel is used, the emissions benefits are sharply reduced.

Because pure biodiesel contains no sulfur, engines that use it can take advantage of the most advanced diesel emission controls to reduce particulates and smog-forming gases even further. Pure biodiesel produces 78% less carbon dioxide than conventional diesel. Actual tailpipe emissions of CO2 are higher with biodiesel, but when the recycling factor (from the CO2 that soy or other crops absorb) is considered, the overall CO2 decreases.


BIODIESEL EMISSIONS COMPARED TO CONVENTIONAL DIESEL
Pollutant..........B100......B20
Hydrocarbons.......-56%.....-11%
Carbon Monoxide....-43%.....-13%
Particulate Matter.-55%.....-18%
NOx................+6%.......+1%
Air Toxics.... ...-60-90%...-12-20%
Mutagenicity.....-80-90%....-20%
Source: U.S. DOE, National Renewable Energy Lab, Factsheet # DOE/GO-102000-1048, May 2000

Biodiesel is compatible with any diesel engine
Biodiesel does not require changes to vehicle fueling systems and can be blended with regular diesel. However, because pure biodiesel is a solvent, it can cause rubber seals to fail, requiring replacement with non-rubber parts in older vehicles.6 Moreover, in cold weather, it has a tendency to thicken, requiring special treatment. Switching from conventional diesel to pure biodiesel requires minor extra maintenance. However, it offers some non-emissions benefits as well, such as safe handling, good fuel economy due to its high Cetane number and flash point7 , and increased lubricity.

Supply and infrastructure are limited but growing.
Currently there are 14 different biodiesel producers in the U.S, with a combined production capacity of 60 – 80 million gallons per year and growing. Costs range from $1.50 to $2.50 per gallon for pure biodiesel wholesale, averaging roughly $1 more than conventional diesel.8

Minnesota recently passed a statewide measure requiring 2% biodiesel in most diesel fuel sold by mid-2005; many other states have considered legislation favoring biodiesel. More than 100 major fleets have biodiesel programs using blends of biodiesel ranging from 2 to 20%, including the US Postal Service and various branches of the military. Use of biodiesel by government fleets may be motivated in part because it is eligible for EPA alternative fuel credits. 9
Pure biodiesel, though still a small niche market, is used by:
Marine: Water taxis in Newport, Rhode Island are running on 100% biodiesel, which is also available in the Florida Keys, Chesapeake Bay, Great Lakes and, to a limited extent, in California bay areas.
Waste/Recycling Trucks: Berkeley's Ecology Center is running its ten-truck fleet exclusively on Biodiesel, while a San Jose recycling and garbage company is modifying 95 trucks to operate on B100.
Hospitals: St. Mary Medical Center in Long Beach switched to biodiesel for on-site generators and boilers. The biodiesel has an additive to lower NOx emissions.10

Biodiesel blended with petroleum diesel is not considered an alternative fuel.
In many cases, NRDC believes that cleaner alternatives are better choices for fleet operators. In particular, blended biodiesel (e.g., B20) seems unacceptable for most uses, because it fails to offer much air pollution benefit. Biodiesel made from virgin oils, such as soy, creates a number of other problems due to farming practices, including soil erosion and use of GMOs, pesticides, and other farm chemicals.11 Additionally, the use of a small amount of biodiesel blended with mostly regular diesel creates the opportunity for greenwashing, where cleaner fuels and after-treatments could be used to really clean up the air. The following summarizes the issues with various blends of biodiesel. To the extent that blended biodiesels are used, NRDC urges fleets to require that the biodiesel portion of the fuel is from waste grease, rather than virgin oils.

B100: NRDC believes that pure biodiesel, while not the cleanest choice where natural gas is available, is appropriate for use in marine and farming applications, both of which emit huge quantities of diesel emissions that have been difficult to regulate. In particular, the biodegradable characteristics of biodiesel make it well suited for marine use, as fuel spills create less ecological impact. In rural areas, it could be produced on-site for use in farm equipment, giving farmers a measure of fuel independence.12 B100 is a good transition fuel for older diesel equipment that is not yet ready to be retired.

B20: Low blends of biodiesel, such as B20, do not offer enough environmental benefits to make up for the high percentage of conventional diesel in the blend. Instead, NRDC strongly urges diesel fleets to use ultra-low sulfur diesel fuel, in conjunction with diesel particulate traps or filters instead—doing so will provide significantly greater reductions of particulate matter emissions, and help speed the implementation of EPA’s and California’s ground-breaking 2007 emission standards, which will require highway diesel vehicles to be 90-95% cleaner than today’s models.

B2: NRDC believes that B2 (an almost entirely conventional fuel that contains only 2% biodiesel in the blended fuel) is only appropriate for large market uses, such as blending requirements for an entire state. In such large-scale uses, the imported petroleum it replaces could become significant. However, biodiesel only has the feedstock capacity to replace about five percent of petroleum diesel nationwide.13

* * *

The Natural Resources Defense Council is a national, non-profit organization of scientists, lawyers and environmental specialists dedicated to protecting public health and the environment. Founded in 1970, NRDC has more than 500,000 members nationwide, served from offices in New York, Washington, Los Angeles and San Francisco. More information is available through NRDC’s Web site at www.nrdc.org. Since 1993, NRDC’s Dump Dirty Diesels Campaign has led the fight for cleaner trucks, buses, construction and other nonroad equipment in California, New York and the nation.



Sources:
http://www.epa.gov/OMS/models/biodsl.htm http://www.greenfuels.org/bioindex.html
http://www.veggievan.org/ http://www.veggiepower.org.uk/main.htm
http://www.biodiesel.org/cgi-local/showpr.cgi?action=view_pr&id=27 http://www.webconx.com/biodiesel2.htm
http://www.ott.doe.gov/biofuels/what_are.html http://www.afdc.doe.gov/altfuel/bio_general.html
http://www.biodiesel.org/Press%20releases/PressReleases00/channelislepr.htm http://www.biodiesel.org/default2.htm
http://www.cytoculture.com/Bdiesel.html

1. Personal communication with Dr. K. Shaine Tyson, Renewable Diesel Project Mgr, National Renewable Energy Lab, 2/25/02. Because the subsidy has expired, many experts expect a return to used grease as a feedstock.
2. Calculation based on Minnesota Department of Agriculture data: Minnesota produced 285 million bushels of soybeans in 1998, over 10 percent of U.S. production; a 2 percent blend of 550 gallons of soy-diesel requires 7.4 million bushels of soybeans. http://www.mda.state.mn.us/AMS/ecoimpsoydiesel.html
3. From the Energy Information Administration, www.eia.doe.gov, expressed in gasoline-equivalent gallons.
4. The catalyst is usually sodium or potassium hydroxide.
5. Testing by Southwest Research Institute (SwRI) on behalf of the National Biodiesel Board and submitted to EPA for Tier I requirements under Section 211(b) of the Clean Air Act, April 1998, indicates different emission reductions for B100: -95% hydrocarbons; -50% CO; -30% PM; +13% NOx; -75-85%PAHs; and > -90% n-PAHs.
6. VitonTM and other non-rubber materials are typically used to replace things like O-rings, gaskets and hoses. Additionally, oil filters need to be replaced more often, especially directly following conversion to biodiesel. This is especially common for vehicles manufactured prior to 1994.
7. Biodiesel is safer to transport because it burns at a much higher temperature, 300º F, compared to diesel which burns at 125º F.
8. Biodiesel is taxed the same as regular diesel, one source estimates an extra $0.50 per gallon in taxes.
9. For every 450 gallon purchase of pure biodiesel, a fleet gets one credit towards required alternative fuel vehicle (AFV) purchases, or EPAct requirements.
10. A product of World Energy (www.worldenergy.net)
11. Biodiesel derived from farmed oils has similar issues as ethanol derived from corn.
12. A project is already underway to develop simple production methods using materials readily available to farmers. (http://wsare.usu.edu/frg/2000/FW00-014.htm)
13. Substituting pure biodiesel for petroleum diesel reduces life cycle consumption of petroleum by ~ 95%, according to An Overview of Biodiesel and Petroleum Diesel Life Cycles, USDA & US DOE, May 1998.

This message has been edited. Last edited by: jeepin, moggin Jessup (coachgeo),

BTW.. I sent the link to the algae pond study to these folk.

quote:

---

a) It's prone to being massively diluted ("blended") by regular dirty diesel.
b) There's not enough of a feedstock supply to make a big dent in overall diesel use in the US.
c) Some feedstocks, particularly farmed oils, can have serious negative impacts to the environment. Consider the use of GMOs, pesticides, fertilizers and polluting diesel equipment in farming those oils, plus other environmental problems related to farming: Erosion, mono-crops, etc.

Given the above issues, we don't support biodiesel as a feasible solution to the problems caused by diesel. Instead, NRDC advocates for it in it's pure form in certain niches: marine, remote locations, and exceptionally responsible passenger car owners.

---

I'm sorry, that is a lame response. Because it can be blended with diesel, it's not feasible? For that reason I say it is feasible.

And just because there is not enough production right now, we should not encourage it's production?

And the farming issues are indeed valid, but considering farm machinery can operate on biodiesel already, that already minimizes one impact. Also some of the oil seed crops are rotatable with others - we don't HAVE to grow the oil stock like we do other crops - that seems to be a separate issue.

I'm really disappointed with NRDC.

I guess I'll just park my Earth-friendly veggie truck under my Elm tree and wait for MegaCorp to deliver that brand-new hydrogen-fusion powered hovercar they've been talking about.

Zzzzz...

(Rip Van "Bio" Winkle -- wake me up in 100 years!)

George, you are awesome for taking the initiative on this one. I read the same article and (embarrassingly enough) didn't do anything about it. Please see my blog entry, inspired by this thread----> http://www.livejournal.com/users/ybiofuels/20686.html?mode=reply

Thanks

These explanations by NRDC are pretty lame, and, I suspect, pretty outdated. They need to do some more research using recent studies.

The biggest ommission I see here is that they COMPLETELY ignore the global warming benefits of biodiesel/WVO. They prefer natural gas over veggie fuels? Come on...

Great replies guys, but don't tell "us" your thoughts. Tell them to "NRDC"! Then pop back in here and tell us about NRDC's next wave of lame excuses LOL.

The links to tell it to NRDC is previously shown in this thread. Also, you could use the one Kumar set up for us. (Thanx Kumar)

This message has been edited. Last edited by: jeepin, moggin Jessup (coachgeo),

I'm just guessing, but one possible objection to increased NOx could be based not on a comparison betwenn bd and petro in a diesel engine, but NOx production between a diesel and a gasser.
I believe NOx is much less in a gasser vs. diesel. If the world world switched to biodiesel, NOx would go up significantly.

jburke: You are right about that, except it's not that simple. Additives have already been developed that reduce NOx from biodiesel. Also, a variety of new studies are showing that reducing NOx actually INCREASES smog, because they are learning that NOx actually EATS smog under certain conditions. It's called NOx scavenging, and it's challening previous assumptions about smog control. In California, for instance, the obsession with NOx control may actually be making smog worse.

It's also widely known that hydrocarbons are a bigger factor in smog formation than NOx, and biodiesel SUBSTANTIALLY reduces hydrocarbons, whether you're comparing it to gasoline or petro diesel.

Folks,

Jeepmoggin is right. Send NRDC an email and say you'll never join and never give money until they get real about biofuels. I have been working in the environmental movement for many many years, specifically in fuels. NRDC, like some but not all enviro groups, falls in love with perfect far off solutions that get squashed by industry minutes before inception (re: electric vehicles). They dont support practical solutions. Ultimately, their issue comes down to an opposition to the combustion of any fuel whatsoever. Basically, they are right in a sense: internal combustion engines should have been eliminated decades ago (it was proposed in Congress in 1975). But unfortunately, the world we live in, oil and auto industries rule to the detriment of everyone else.

So NRDC waddles along criticizing politically practical solutions like biodiesel, veg oils, ethanol, etc. that could actually shake the foundations of the oil cartel, while getting behind great ideas that are secretly laughed at behind closed doors at Exxon. Dont get me wrong ... new technology is a great idea. But the Model T got 27 MPG. The rig is in. It's time to get nasty and make decisions based on weakening the giant, not creating eden.

Wannawagon: I'd love to get more info on NOx smog eating. I am in daily contact with CARB.

Oh yeah, forgot to mention, the rumor on the street is also that NRDC is "tight" with Natural Gas. Catch my drift?

U of Idaho have developed strains of Mustard and Canola who's biodiesel makes NOx as low as diesel.
Catalytic converters are only just now showing up on US diesel engines, and can drastically reduce their NOx output even below Gasser levels. It's hard to get the cat to stay lit during top and go driving with a diesel though, because of the excess air getting pumped through. The most common solution is EGR, which many folks (in the US) hate for no understandable reason (clogged valves?) and choose to disconnect, increasing the pollution.
I was under the impression that NOx/smog formation was a well understood chemical reaction. Is the alternative theory based on something real, or bogus new-age science?
Personally, I think Mr Fusion - powered DeLoreans offer the best hope.
Cheers,
JohnO

Sorry for the long post, but since you asked:

"NOx scavening" is also known as the "weekend effect" because studies are showing ozone spikes on weekends when there are fewer diesel trucks on the road (and hence, less NOx in the air). Below is an L.A. Times story from May on the phenomenon. You can also do a Google search for "nox scavenging" and get a ton of articles.

This one, dating way back to '99, basically says the reaction between NOx and volatile organic compounds (VOC, or hydrocarbons) is "VOC limited," meaning that if you take out the VOC, the NOx by itself won't make ozone:

http://vchd.evvindiana.org/oztrendsreport.html#ozone

By Miguel Bustillo
Los Angeles Times
Mon May 24, 7:55 AM ET

As Southern California experiences a resurgence of smog, a growing number of scientists say the government's long-standing strategy for reducing air pollution may be making it worse.
 
The doubts have arisen because ozone, the main ingredient of smog, is becoming more common in Los Angeles and many other large cities on weekends, when big trucks and other heavy polluters are least active.

Known as the "weekend effect," the phenomenon has long perplexed scientists and air pollution officials, who remain divided over why ozone is so abundant Saturdays and Sundays.

Now, some scientists, armed with new research about the weekend effect, are suggesting that environmental officials may be putting too much emphasis on the wrong pollutant because they misunderstand how smog forms in the atmosphere.

The dispute centers on one of the two main groups of chemicals that react to form ozone: nitrogen oxides, which are released into the air when fuel burns. Air quality regulators have pushed hard to reduce those chemicals as much as possible. It's been a costly process, particularly for the auto industry, and some scientists say it may be time to pull back.

"It seems like motherhood and apple pie to reduce pollutants. That sounds like a common-sense approach," said Douglas R. Lawson of the National Renewable Energy Laboratory in Colorado.

"But things are not that simple. The more intelligent way to approach the question of pollution controls is: How will the atmosphere respond to the changes?"

Lawson and those who agree with him argue that regulators should put less emphasis on nitrogen oxides and focus more on reducing the other main constituent of ozone, a class of chemicals called volatile organic compounds. Those compounds have many sources, natural and man-made, including household cleaners, cars and trees.

A lot is at stake in the debate.

Auto industry groups have tried to use the weekend effect as a rationale for weaker antipollution rules. During state hearings in 1998, for example, automakers said sport utility vehicles should not have to meet the same emissions standards as regular cars.

The scientific arguments against cutting nitrogen oxide emissions may bolster their case.

At the same time, a push to reduce volatile organic compounds could boost efforts to get old cars off the road. Those vehicles are major sources of the chemicals. Gov. Arnold Schwarzenegger (news - web sites)'s administration has proposed such a program; its plan would cost hundreds of millions of dollars and weigh disproportionately on people who can't afford newer vehicles.

Officials from the California Air Resources Board and the South Coast Air Quality Management District concede that the arguments by Lawson and others cannot be dismissed. But they say that changing successful strategies based on unproven claims would be irresponsible.

"The weekend effect is something you can see in different parts of the country and the world, but people tend to overemphasize it," said Leon J. Dolislager, a state air board official who has researched the phenomenon. "We have to keep our eye on the big picture, not overreact."

In Southern California last year, 68 days exceeded federal ozone standards — nearly twice as many as two years earlier. A disproportionate number of the bad air days over the last five years have been Saturdays and Sundays. In Los Angeles County, 43.5% of the 260 days exceeding a federal ozone standard fell on weekends.

It remains to be seen whether the smog increase is a sign of serious problems or an anomaly caused by unusual weather and massive wildfires, as some air experts have theorized.

Ozone, a colorless and odorless gas, is formed in a photochemical reaction involving nitrogen oxides, carbon monoxide and volatile organic compounds. Laboratory research has shown that altering the ratio of nitrogen oxides to volatile organic compounds in the air can cause more ozone to form. Some scientists theorize that by slashing nitrogen oxide pollution in recent years, state and federal regulators have made the air above Los Angeles more conducive to ozone formation.

Although officials have been cutting both pollutants, they have reduced nitrogen oxides more rapidly over the last decade.

Some experts — most notably Lawson and Eric Fujita of the Desert Research Institute in Nevada, both former California air pollution officials — believe that regulators could keep ozone in check better by slowing the pace of nitrogen oxide reductions while doing more to cut volatile organic compounds.

Over the last quarter century, by drastically reducing both pollutants, regulators have slashed peak ozone levels in the Los Angeles area by 60%, even as population has grown by 50% and traffic nearly doubled. By 2010, environmental regulations will have reduced nitrogen oxide enough that the atmospheric changes seen on weekends will be present all week, Lawson predicts.

"What we are saying is that in 2010, ozone could be worse than it is now; that is the bottom line," he said.

California officials said in a detailed report last year that there might be other explanations for why ozone in urban areas was often worse on weekends.

One theory holds that emissions from weekdays remain aloft and "carry over" to the weekend.

According to another theory, nitrogen oxide emissions from regular cars and trucks, which typically crest during the morning commute on weekdays, peak around noon on weekends. At that hour, the sun is brighter and atmospheric conditions are different, which might cause ozone to form faster.

"There are plausible hypotheses that do not involve the [nitrogen oxide] reduction question," said Richard Corey, head of the California air board's research branch.

State officials, however, increasingly appear to be in the minority. Researchers have found the weekend effect in American cities as diverse as San Francisco, Chicago, Denver and Philadelphia — and many experts say reduced nitrogen oxide appears to be a big reason.

The state officials "are the only ones who seem to believe" that reduced nitrogen oxides are not a leading cause of the weekend effect, said George Wolff, principal scientist for General Motors, who published an article on the phenomenon last year.

Robert Harley, a professor of environmental engineering at UC Berkeley, analyzed 20 years of air-monitoring data throughout California and found that the weekend effect, once seen only in coastal urban areas, could now be observed as far inland as Sacramento and the northern San Joaquin Valley. Like other experts, he concluded that reductions in nitrogen oxides on weekends seemed the most credible explanation for the spike in ozone levels.

"We found the change in diesel truck emissions to be much more important" than the later start time for regular cars on weekends, said Harley, who considered both hypotheses.

California officials remain committed to rapidly cutting nitrogen oxides. In addition to helping cause ozone, they note, nitrogen oxides contribute to another type of pollution: particulate matter, tiny flecks that can become lodged in the lungs and cause serious respiratory problems. Diesel particulate matter is responsible for 70% of the cancer risk from airborne toxic substances in Southern California, according to a government study.

"To address that, we have to do everything possible," said AQMD spokesman Sam Atwood.

hi johno,
do you have a link or any more information on the low-NOx strains of canola and mustard?

" There are a variety of reasons certain plant types are used as fuels. Brassicaceae oils are relatively low in saturated fats, have a lower pour or melting point, and it has better cold flow properties than soy oils. They are also relatively low in polyunsaturated fats which equals to lower nitrous oxide emissions."
Excerpt from the U of I biodiesel web page. I have a brochure mentioning the reduced NOx, but don't have a link to a related report. See also this