What are the benefits and drawbacks of using biodiesel fuel?

[Ivan Seeking]

Biodiesel fueling stations are sprouting like weeds across America, where production of the alternative fuel rose 66 percent in 2003. Experts say the rapid growth of the renewable fuel will stretch the country's tenuous petroleum supply while helping people breathe a little easier.

Damon Toal-Rossi of Iowa City, Iowa, jumped on the biodiesel bandwagon after a friend outlined the benefits of using a fuel made from soy or vegetable oil. The software programmer liked the idea of a cleaner-burning fuel that reduces dependence on foreign oil so much that he traded in his gasoline-powered pickup truck for a diesel-powered Volkswagen Golf. [continued]

http://www.wired.com/news/autotech/0,2554,63635,00.html?tw=wn_story_top5

For more information on Biodiesel, please see
http://www.biodiesel.org

 

[Ivan Seeking]

I was doing some reading and found some interesting information at the John Deere farm equipment website.

Biodiesel Fuel in John Deere Tractors

Symptoms
Using biodiesel fuel in your John Deere tractor.
Situation or Problem
Biodiesel fuels are formulated in many different blends and concentrations.

Solution Steps
Biodiesel fuels may be used in John Deere diesel engines only if the fuel meets the provisional ASTM PS121 (U.S.) or DIN 51606 (German) specification listed in Table A, see below. NOTE: Raw pressed vegetable oils are NOT acceptable for use for fuel in any concentration. These oils do not burn completely, and will cause engine failure by leaving deposits on injectors and in the combustion chamber. While a major environmental benefit of a biodiesel fuel is its ability to biodegrade, users must recognize that storage and handling is of prime importance as indicated below:
• Ensure the quality of the biodiesel fuel (fuel meets the specifications in Table A).
• Keep storage and vehicle tanks as full as possible to prevent moisture from collecting inside.
• Ensure all tank caps and covers are installed properly to prevent water from entering.
• Monitor water content of the fuel regularly (Bonds with water, creating acids).
• Limit the storage tanks from extreme temperatures (i.e. Direct sun or frost).
• Limit the storage to 3 months due to shelf life (degrades quickly, microbes, oxidation).
• Wash down spills with clean water immediately to prevent corrosion and damage to paint.
• Fuel filter may need to be replaced more often due to premature plugging.
• Check engine oil sump level daily prior to starting, a rising level may indicate lubricating oil dilution. This check is important for all engines and even more critical for engines equipped with rotary fuel injection pumps.
• Instability resulting from blending biodiesel with mineral diesel fuel.
• Consult your fuel supplier for additives to improve storage and performance of biodiesel fuels.

Blending biodiesel fuel above a 5% concentration could have some adverse affects to the engine, such as:
• Power loss and deterioration of performance
• Fuel leakage through seals and hoses
• Corrosion of fuel injection equipment
• Lubricity of biodiesel and the fuel injection equipment
• Coked/blocked injector nozzles, leading to poor atomization of fuel
• Filter plugging
• Lacquering/seizure of internal injection system components
• Sludge and sediments
• Reduced service life
When using a blend of biodiesel fuel in a rotary fuel injection pump, the engine oil level must be checked daily when the air temperature is -10° C (14° F) or lower. If oil becomes diluted with fuel, oil change intervals must be shortened. Correct intervals may be established by using OilScan ™ /OilScan Plus™ programs. Another factor due to cold temperatures is the cloud point of the fuel. When blending biodiesel the temperature at which the fuel will start to cloud is changed, Consult your fuel supplier for biodiesel cloud point specification. John Deere product warranty only covers defects in material and workmanship as manufactured and sold by John Deere. Failures caused by the use of biodiesel fuels or other fuel additives are not defects of workmanship and/or material as supplied by John Deere, and cannot be compensated under John Deere warranty. Users of John Deere emission certified engines are responsible for obtaining the proper local, state, and national exemptions required for the use of biodiesel. See Provisional Specifications for Biodiesel Fuel (B100) in Table A. NOTE: Experience shows that biodiesel is not always conforming to standards defined. In addition, the specifications listed in Table A are broadly defined which results in variation of the biodiesel quality. The FAME fuel composition can vary in quality. This variation of quality can cause fuel injection system failures with all engines. IMPORTANT: The operator must ensure the supply of qualified biodiesel used, does not harm any parts of the engines fuel system.
See your local John Deere Dealer for additional information.

http://www.deere.com/en_US/ag/servi...rs/9000/Biodiesel_in_John_Deere_Tractors.html

It seems the tractor people and the biodiesel people have some very different perceptions of this as a fuel. The Biodiesel website indicated that deterioration problems with the seals are resolved with the lastest materials used in response to Diesel #2, and the plugging of fuel lines results from the higher detergent value of the biodiesel cleansing out the accumulated residue from previously used, ordinary diesel fuel; in fact this issue of plugged lines is cited as a myth.

I'm not sure what to think.

 

[kirkmcloren]

journeytoforever.org has the best info on alternative fuels (biodiesel and alcohol and methane) that I have seen.

BTW a Canadian university, Calgary I think, published as little as 8% canola biodiesel added to petro diesel will reduce engine wear by 40%.

 

[russ_watters]

I'm not sure what to think.

Both sides have an adjenda, so the truth is somewhere in between. John Deere doesn't want to get sued if someone destroys their engine and biodiesel proponents don't want to admit that it isn't as good as regular diesel.

 

[Ivan Seeking]

I emailed the local biodiesel supplier [there is or was one] but I never received a response. I made some calls to truck and tractor dealerships in the area and most people knew nothing more about it than the name.

Even though I tend to agree with your conclusion here I am still a bit surprised to find some specific information in direct contradiction. For example, the biosdiesel people claim the fuel is much cleaner, a better lubricant, and it is less corrosive than diesel. But we find at the Deere site that corrosion of the fuel injection equipment and the lubricity of biodiesel in regards to the fuel injection equipment are problems.

 

[russ_watters]

Even though I tend to agree with your conclusion here I am still a bit surprised to find some specific information in direct contradiction. For example, the biosdiesel people claim the fuel is much cleaner, a better lubricant, and it is less corrosive than diesel. But we find at the Deere site that corrosion of the fuel injection equipment and the lubricity of biodiesel in regards to the fuel injection equipment are problems.

Sounds to me like an undergrad engineering project waiting to happen...

 

[pebrew]

I've been reading a lot about biodiesel recently, mainly online, and I have to say it looks like a pretty good fuel. Perhaps even better than H2 fuel cells. By 'better' I mean essentially as clean and similar or increased fuel efficiency (with production taken into account).
It is much cleaner than petrodiesel when burnt (http://www.journeytoforever.org/biodiesel.html). Even the slight increase in NOx emissions could be reversed by an exhaust technology that can't currently be used because of the sulfur in petrodiesel (http://www.journeytoforever.org/biodiesel_nox.html). Most importantly, in many environmentalists' minds is that biodiesel is mostly (80-90%) composed of vegetable oil, so it is a carbon neutral fuel, not adding any net CO2 to the atmosphere. So if you're concerned humans cause global warming, this product will at least help level off the CO2 in the atmosphere.
Biodiesel is also better for your engine. It is an incredible solvent (can even strip paint).
It is biodegradeable and non-toxic.
It can be (and it currently) produced using domestically grown veg oil. Therefore no money going to the middle east or big oil companies (for now).
It smells nice when burnt (like donuts).
Engine performance is 'about the same'. I've read about both slight improvements and reductions in power and mileage.

You can even make the stuff your self, and very cheaply. Biodiesel is simply vegetable oil that has had the glycerin removed (through esterification). That process involves mixing about 200ml methonal and a couple grams of lye with a gallon of veg oil and letting it sit for a few hours. You can even use waste veg oil (or WVO, free from restaurants) to make it. (There are other methods of esterification, but that's the one most homebrewers use).

The John Deere article looks to me to be mostly to cover their butts out of liability. Any diesel engine is able to use biodiesel. I do not use biodiesel (have to diesel engines in my possession) and most of the reading I've done has concerned passenger vehicle and pickup trucks. But I've seen articles about it's use in boats, furnaces, and farm equipment. And there's no theoretical reason it should work any worse in those situations. Two problems Deere mentions are definitely possible:
1. Because of biodiesel's superior solvency, it can deteriorate hoses and seals made out of old rubber. The material such car parts are made out of today do not deteriorate via biodiesel and if you've got old rubber it is supposedly cheaply replaced.
2. When a vehicle has been running petrodiesel for a long time (say, 100k miles in a car) it can collect gunk at the bottom of the fuel tank and in the lines, etc. If a biodiesel is used in that vehicle straight (that is, 100% biodiesel. it is often blended to 20%bio/80%petro or less) the solvency of biodiesel can easily pull the petrogunk off the fuel tank which can then get pulled into the fuel lines. This appears to be a common problem in cars, so when switching fuel it is advised that you have a couple extra fuel filters on hand. So this is a temporary problem that can crop up when using B100.

Another of Deere's concerns is kind of possible. Diesel engines were originally designed to burn straight peanut oil, not even biodiesel. And, in fact, they still can. The trouble with straight veg oil (SVO) is that it is much more viscous than petrodiesel so it can coke up fuel injectors. Synthesizing veg oil into biodiesel (removing the glycerine) is one way to make it less viscous, enough so that it runs fine through the engine. But another way is to simply heat the SVO before it goes into the engine. If you heat it to about 170F, the SVO's viscosity is adequately reduced to burn happily in the engine. To accomplish this many people add a second fuel tank to their vehicle that has a little heater in it. Start the car with petrodiesel, after a couple minutes you switch to SVO once it's warm enough. People sell kits to convert a diesel car like this for $500 (http://www.greasel.com/). Then you can go get some free waste veg oil, filter it, and throw it in your car.
So when Deere mentioned the coking, they may have been thinking of the SVO issue. It may be possible for biodiesel to have similar problems in cold, <40F, weather, but if that's the case it can be blended down slightly (say 20% petrodiesel) to end that problem.

Personally, I'm more excited about the idea of running an SVO car than biodiesel, but I'm not sure if SVO is quite as clean as biodiesel. I'm hoping to get an old diesel car in the next year and start.


Here are some excellent biodiesel websites, they discuss SVO a little, too:
http://www.journeytoforever.org/biodiesel.html
www.biodiesel.org (industry trade group)
http://www.biodieselnow.com/ this site has a big forum with lots of people who run biodiesel in their cars all the time.

 

[Ivan Seeking]

It smells nice when burnt (like donuts).

So from Biodiesel we get the smell of donuts, and from H2 internal combustion we get the smell of clean laundry. The cities will never be the same.

Nice post pebrew.

 

[Ivan Seeking]

I heard yesterday the a local guy runs his auto on cooking oil obtained from restaurants and fast food places. The car smells like french fries.

 

[Averagesupernova]

With just about ANY new fuel type there are issues. Back when we still had leaded gasoline older cars had a problem with unleaded because the lead actually helped lubricate valves.

Along came ethanol. They said you can use it in ANYTHING. Well, you can, but not without small problems. In engines running ethanol (especially carbureted) the rubber and seals in the fuel system deteriorate quickly if they are only occasionaly run. Ethanal tends get old quicker than straight unleaded. In this state it is very hard on some rubber parts. I can't count how many accelerator pumps I put into an older carbureted vehicle that is occasionally run before I figured out NOT to burn ethanol.

I will say this though, ethanol tends to be a very good solvent. This can be detrimental in some cases as already mentioned with the biodiesel. If you want to keep your fuel system clean in a new vehicle, use ethanol from day one. On a used vehicle which you don't know the history of fuel useage, think twice or be prepared to replace filters and such when the ethanol starts to loosen the stuff that the gasoline left behind.