What is the difference between bioethanol and biodiesel?

Question

What is the difference between bioethanol and biodiesel?

Answer 1

Biodiesel is made out of a variety of different things (e.g. algae, corn, canola, ect.). You can you use Methanol or Ethanol to catalyze a reaction that makes "Biodiesel" from an oil base. I have a VW Jetta TDI that I use 100% bio-diesel in. It runs great. I get about 44 mpg (highway). I have a research paper I wrote on it if you would like more info.

***** You do not have to modify a diesel car to use it. You have to make modifications when you use SVO (Straight Vegetable Oil).  Older diesels may also have issues because of the gaskets will break down. **********

Bioethanol I assume is made out of similar products but, is an alcohol. From what I understand it burns less efficiently so fuel economy is not that of a diesel. However, it burns cleaner than the status quo.

Answer 2

diesel fuel is made in the same process as gasoline. ethanol is made from renewable resources and is produced from vegetables. it is a hard situation to decipher which is better for the environment. with diesel gasoline or even biodiesel which is made from renewables also, gets you much higher efficiency and MPG than that of ethanol. ethanol through the refining and marketing process pollutes almost as much as its gasoline counterpart while also getting lower efficiency and MPG ratings from cars. i do not see biodiesel or bio ethanol becoming the big fuel saving, oil saving technique. the future hinges on hybrid solar hydrogen technology. some elements of all three are being tested in production cars and buses by many manufacturers including GM. i hope i was helpful to you.

Answer 3

Ethanol: Most ethanol produced today is corn based but significant quantities are also produced from sugar cane and sugar beets. This process is inefficient from several perspectives. Firstly the amount of ethanol that could be produced this way is extremely limited and could never provide more than a small fraction of our liquid fuel needs. Secondly it encroaches on our food supply and is already driving up corn prices. An alternative method of making ethanol uses the woody part of the plant rather than the sugary/starchy part. That would allow for instance corn stocks to be used to make ethanol while we could still use the corn itself for food. In addition there are excellent very fast growing plants that would provide considerable cellulose feedstock with greatly reduced farming inputs, which greatly improves the overall energy efficiency for generating ethanol. Even so the highest estimates indicate that ethanol could only provide about 40% of our current oil consumption. On the plus side ethanol can be burned in our cars with very minor changes and can be distributed using our existing infrastructure making the rollout of ethanol highly feasible. Ethanol contains less latent energy than does gasoline or diesel and therefore cars using it will get lower mileage. That might be partially compensated for in engines dedicated to ethanol if it becomes ubiquitous because ethanol could be used in very high compression engines that are inherently more efficient. However that is impossible if the engine must be flex-fuel capable.

Biodiesel: Biodiesel basically uses plant oils (animal oils will work too) to make a diesel substitute. Certain types of plants can produce bio diesel economically and quite a few people are making use of waste oils from restaurants but in truth these sources are likely to be even more limited than ethanol. I am not aware of any processes proposed for making biodiesel from cellulose sources and in my opinion that is required to for any plant based fuel to be widely viable. Biodiesel is likely to be a niche product going forward due to limit supplies, but it will certainly be part of the mix because it makes very efficient use of sources that would otherwise merely be waste. It also can be used in existing diesel engines without modification and can make use of the existing distribution system. Biodiesel has a high latent energy and runs in high compression diesel engines and so it achieves comparable mileage to fossil diesel.

Answer 4

Biodiesel is made from plant or animal oils/fats.  Ethanol is alcohol, and is made strictly from plants (usually corn or soybeans); it is not usable in a diesel engine, but must be used in a modified gasoline-type engine.  They are both renewable fuels, just different types that can be used in different types of engines.

Answer 5

Everyone has done a wonderful job of explaining what biodesel and bioethanol fuels are, how they're made and their contribution to saving our environment.  But to answer your question, quite simply, the difference between bioethanol and biodesel is this:  Bioethanol is a GASOLINE replacement (for use in vehicles and things that use unleaded gas), while biodesel is a DIESEL fuel replacement (for use in vehicles and things that use diesel fuel).

Answer 6

Biodiesel vs Ethanol

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Biodiesel Versus Ethanol the alternative fuels showdown

There are a lot of ways to compare biodiesel and ethanol. Here are a few. Please contribute to this page, but make sure to cite your sources!

__Gallons per acre:Corn ethanol yields about three times as much usable fuel per acre compared to Soy biodiesel, but neither are optimal crops.

Corn yields 230 gallons per acre for ethanol(source: EERC). Brazil's program that produces ethanol from sugar cane currently achieves about 600 gallons per acre. site has a table with the yields for other crops.

Most U.S. biodiesel is made with soybean oil which yields a low 70.13 gallons per acre. Euro biodiesel is primarily rapeseed which yields a better 127g/a, while palm oil yields an impressive 635g/a. Biodiesel can also be produced from algae, but it remains to be seen how many gallons per acre that will yield. (source: Journeytoforever.org)

The cooperative makes biodiesel from "waste" veggie oil, so yield per acre probably isn't the best model.

Interestingly, it takes a staggering 196,000 pounds of prehistoric plant matter to create 13 pounds of crude. This crude yields 6.2 pounds (one gallon!) of gasoline.

__Mileage:__ using biodiesel doesn't really have an impact on mileage. Ethanol has a lower energy content than gasoline, so vehicles using E85 typically get about 25% lower mileage than vehicles using gasoline. In addition, biodiesel benefits from the inherent fuel economy in diesel engines (20-50% better than comparable gasoline engines).

__Emissions:__ Both biodiesel and ethanol benefit from the carbon cycle, that is, burning either of them results in zero new C02, since the same amount of CO2 is taken in during the plant's lifecycle.

Someone needs to make a grid of this to make some sense: Ethanol 30% less CO2, Biodiesel 74% less (source: US DoE) Other emissions need further researching, but it appears from a cursory investigation that biodiesel has far lowered emissions across the board than ethanol.

__Compatibility:__ biodiesel runs in any diesel. It isn't clear that any vehicle can run on 100% Ethanol. Usually Ethanol must be blended with 15% fossil fuel gasoline, and is only compatible in a small fraction of gasoline powered vehicles.

Most gasoline in the US is already blended with a small amount of ethanol at certain times of the year.

__Costs:__ Apparently you can't buy E85 at the pump in Oregon even if you wanted to. Or in Washington State. There's a pump in San Diego, California. Federal subsidies make the cost at or less than gasoline.

Commercial biodiesel has no federal subsidies and is currently more expensive per gallon, about 5-20% more than gasoline mile per mile (because of diesel's greater fuel efficiency).

__Energy yield:__ You get 34% more energy out of ethanol than is required to produce it(from corn). On the other hand, you get 320% more energy from producing biodiesel than you put into it. (source: US Dept. Agriculture)

[This article] quotes a Cornell scientist who asserts that producing ethanol takes more energy than it gives back. His claim is that it takes 131,000 BTUs of energy to produce a gallon of ethanol, but a gallon of ethanol only has 77,000 BTUs of energy!

More research is necessary.

Retrieved from "http://www.gobiodiesel.org/index.php?ti...

Answer 7

Big differences!

Biodiesel is simply vegetable oil, with a minor chemical modification to make it thinner. (add 1 part methanol for 10 parts veggie oil, add small amounts of lye, heat to 130 degrees.)

Ethanol is fermented and distilled from vegetable starch. .  (make very strong beer; distill 7-12 gallons of beer to make 1 gallon of ethanol).

Gasoline both chemically modified (cracked) and distilled (to separate the parts of crude oil).  1 gallon of crude oil yields 1 gallon of various products - tar, diesel, gasoline, butane, natural gases.

Note the efficiencies here:

http://www.mda.state.mn.us/renewable/ren...

Why is biodiesel so much more efficient?  Because distillation takes enormous amounts of energy, and biodiesel doesn't have to do it.  But ethanol has to do a lot of it :(

Answer 8

Biodiesel, at the moment, is free.  Biodiesel is made from used fry oil (you know, from resturants and such).