Monday, December 13, 2010
3. Engines and Modifications
How does a diesel engine work?
Diesel engines work by combustion. The process starts by air flowing into the four stroke diesel engine, becoming clean as it passes through the air filter. Then it flows through the tubing. It becomes compressed in the turbo’s spinning blades. It gets very hot and dense, and is then cooled by an intercooler. The intake stroke involves air filling the combustion chamber because of the opened intake valve after the piston slides to the bottom of its stroke. The compression stroke involves the intake valves closing, and the piston pushing air up towards the cylinder head. Then the pump sends low pressure fuel to the injection pump. The pressure in the injection pump drastically increases. Fuel is injected to the combustion chamber, which is filled with superheated air, at great amount of pressure. The combustion that results pushes the piston back down. That is called the power stroke. In the final cycle, the exhaust valves open and the piston pushes the exhaust out. The engine still has lots of energy to push exhaust out. Air enters in exhaust and exits out the tailpipe. (Thompson)
What modifications need to be made to engines?
Engines don’t work much differently with biodiesel. Few, if any, modifications usually need to be made to engines using blends of B20 (20% diesel/80% diesel) or below. If the injection system in your engine was built before 1993, however, you may need to replace the fuel lines, gaskets and fuel pump seals because biodiesel can cause the seals to deteriorate. Replace the fuel filter, because “it may remove deposits in the fuel system, which may plug fuel filters or cause deposits to accumulate in the fuel tank.” (Hofman, Rosendahl, et al)
The air/fuel mixing ratio should be reduced. Rubber seals may need to be replaced by non-rubber seals because biodiesel doesn’t get along with rubber. Higher blends of biodiesel may thicken a lot during cold weather, so you might want to get a fuel heating system or use biodegradable additives. With biodiesel, you will need oil changes more frequently. Engine timing should be changed very slightly to improve engine performance in higher blends. (Engine Modifications).
How does biodiesel help/hurt the engines?
Biodiesel can hurt the engine. It may cause deterioration of seals and fuel filter plugs, as discussed in the previous paragraph. Biodiesel may also cause excessive wear, often from air intake or antifreeze leak. The engine would also require more fuel than if using regular diesel. (Hofman, Rosendahl and Webster) There might also be difficulty starting in cold weather (Engine Modifications). There could be a lower energy content, causing “power loss in engine operation” (AMSOIL).
Biodiesel can also help the engine, though. It helps “reduce most engine emissions” (Hofman, Rosendahl, et al). It is very similar to regular biodiesel concerning “operation of compression ignition engines” (AMSOIL). Biodiesel is biodegradable and non toxic. It has improved lubricity and conductivity. It also has a high cetane number[1][1][1]. (AMSOIL)
How do blends affect engines?
Different blends affect engines in different ways. Up to B5, most engines will eb just peachy. “Concentration beyond 5% could have adverse effects on the engine performance and the fuel system integrity and durability.” Also, higher blends might lower “the engine service life and drain intervals.” (AMSOIL)
“Most engine manufacturers do not warranty engines using [blends] higher [than 20%].” Some allow up to B20. Even as little as adding 1 to 2% would “give diesel fuel more lubrication than previously accomplished with higher sulfur content diesel fuel.” The higher concentration of biodiesel, the higher cloud point (which would not be so good), higher cetane number (which would be excellent), and higher viscosity centistokes (but not by much, making it sort of neutral). With the lower concentration, however, there would be fewer operating problems. (Hofman, Rosendahl, et al)
Warranties voided if biodiesel is used?
Biodiesel should not void engine warranties, seeing as the warranties are for the engine, and not the fuel being used by the engine. “Most major engine companies have stated formally that the use of blends up to B20 will not void their parts and workmanship warranties.” The biodiesel does, however, have to meet ASTM D-6751 (Biodiesel.org). Agri-Green Biodiesel stated on their website:
“Warranties are only violated if the biodiesel is the cause of the equipment malfunction… Engine warranty, workmanship and material are not affected simply by the use of biodiesel regardless of the product’s origin… If the biodiesel, or other fuel, is the cause of the problem, then the warranty may be void.”
So, biodiesel shouldn’t be too hard on any engine, where approved blends are concerned.
[1][1][1] “Cetane number is a method for determining the ignition quality of a fuel.” (Hofman, Rosendahl, et al)
4. Environmental effects
-are there long term environmental impacts?
it is 100% renewable and 100% organic. NOx emmision goes up with biodeisel. creates smog and acid rain. caused illness and death, oxygen depleation, and degrades water and harms fish.
-what are some governmental hurdles to overcome?
so much illness and death coming from smog and emmisions are hurting the economy as well as environmental needs.
older vehicles will not use biodiesel.
not available in much of nation yet.
-are there short term environmental impacts?
NOx emision
will reduce all other emisions from other gasses as they are less used.
5. Are there negatives to using biodiesel? What are the useful co-products of biodiesel production?
-can you find all the negative arguments?
increases demand for corn. prices increase.
more expensive for farmers.
increases meat and dairy prices.
requires extreme amounts of water.
increases deforestation.
-can you turn those negative arguments into positives?
with increased livestock prices, farmers get paid more.
agriculture industry well flourish.
-are there any useful biproducts?
biodiesel is a very useful byproduct.
a lot of corn and wheat is used to make it.
Sunday, December 12, 2010
6. How do we get biodiesel? How do we increase availability?
What vehicles are biodiesel-ready?
Almost any diesel vehicle should be able to use biodiesel, at least up to B20, anyhow. “Any diesel engine can use biodiesel.” Lots of today’s car companies also have models that are able to run on biodiesel. (Sheppard)
Where can we go buy biodiesel?
The closest possible place, though, that we would be able to get biodiesel would be a few places in Atlanta or “Down to Earth Energy” in Monroe (Biodiesel.org). That’s a good 45 minutes in any direction. And even there, they would only sell B20. Why, we’d waste much of our just-purchased biodiesel getting home! That’s no way to go.
How do we get someone to offer it where we live?
I suppose that raises the question of just what are we supposed to do? First of all, we would need to find a company here in Conyers to host the selling of biodiesel. After that, we would have to, one way or another, contact a biodiesel producing company (Biodiesel.org’s guide to buying biodiesel says it is not wise to make the stuff our self). Once we find a way to contact them, we would have to put up our petition. We would have to think of some mighty good reasons for them to sell to Conyers. We would have to organize the coming together of the seller and the retailer in Conyers. Then we have it all nice and lovely on our front porch.
What are the biggest hurdles?
Actually, there would be some hurdles. Just how in the world are we going to get someone to work with us, first of all? And then there’s the issue of finding a way for that biodiesel to get out of a pump in the ground (or into it, first of all, I suppose), once we get the people to work with us. Then, we of course would have to be able to influence the people of Conyers to buy the biodiesel. They may not want to vary from what they’ve always done, but we could do it. With a little perseverance, we could just maybe make the world a little greener, one gallon of biodiesel at a time.
Works Cited
AMSOIL. “Biodiesel Fuel and its Effects on Engine Operation and AMSOIL Lubricant Service Life.” AMSOIL (5 May 2006). Web. 27 Nov2010. <http://www.enhancedsyntheticoil.com/Biodiesel_Fuel_Effects.htm>
“An overview of the arguments against biofuels.” forceChange (3 Apr 2008). Web. 12 Dec 2010. <forcechange.com/2008/04/03/an-overview-of-the-arguments-against-biofuels>
Bio-Blend fuels, Inc. “What is Biodiesel?” Bio-Blend Fuels (2010). Web.12 Dec 2010. <http://www.bioblendsfuels.com/biodiesel/%3e
Biodiesel.org. National Biodiesel Board, 2010. Web. 27 Nov 2010. <http://www.biodeisel.org/>
“Engine Modifications”. University of Strathclyde
Hofman, Vern; Rosendahl, Michael; Webster, Jason; Wiesenborn, Dennis. “Biodiesel Use in Engines”. North Dakota State University (Jan 2006). Web. 26 Nov 2010. <http://www.ag.ndsu.edu/pubs/ageng/machine/ae/305w.htm#engines>
Sheppard, Kate. “Find out which cars can run on ethanol and biodiesel.” Grist (5 Dec 2006). Web. 11 Dec 2010. <http://www.grist.org/article/cars4>
Thompson, Jason. “Diesel Engines – How It Works.” Diesel Power (Apr 2009). Web. 18 Nov 2010. <http://www.dieselpowermag.com/tech/0904dp_diesel_engines/index.html>
“Warranties, original equipment manufacturers (oem) and biodiesel”. Agri-Green Biodiesel. Agri-Green Biodiesel, n.d. Web. 27 Nov 2010. <http://www.agri-greenbiodiesel.com/>
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