If biodiesel can be made from leftover cooking oil why do we need to grow corn to make it?

Question

Currently, rainforests are being destroyed to grow sugar to make biofuel. Corn is being grown to make ethanol. Why? Biofuel can be made from cooking oil.

Answer 1

There is not enough used cooking oil to supply all the biodiesel needed.

Answer 2

You can make ethanol from any plant matter. Corn depletes soil at a fantastic rate. At least soybeans put nitrogen back into the soil. If the corn lands were converted to soybeans, you could produce a good fraction of biofuel needed and supply oil for cooking too. I think both ethanols and oils combined would power a lot of vehicles.

What is the solution to jet planes, though. Just think of the thousands of planes flying everyday? A billions litres a day of fuel would not surprise me.

Answer 3

You dont use corn to make biodiesel. Corn is used for ethanol. soybeans are used to make biodiesel.

Just remember, when you use ethanol, you loose 15% of your total mileage right off the bat.

You can get 360 gal of ethanol/acre  from corn.....you could get 1500 gal of ethanol/acre from switchgrass.

The big problem is that switchgrass doesn't have a lobby in washington....like corn does.

Answer 4

I think you confuse ethanol and its sources with biodiesel and its sources.

Actually, ethanol made from corn and sugar cane are not used to make biodiesel.  Ethanol is typically added to gasoline, although it can be burned alone by some vehicles.

Biodiesel is typically made from combining diesel fuel and some amount of vegetable oil (could be from corn oil, soybean oil or rapeseed oil, among other plant oils).

There is probably not enough cooking oil consumed that could be recycled to meet the needs of the entire diesel fleet although its use could make a small contribution to extending diesel fuel supplies by adding it to diesel fuel or using the oil as a diesel substitute in modified diesel vehicles..

Answer 5

Corn is made into ethanol. Biodiesel is made from plant waste (in your case, corn stalks). So if you were growing corn to eat, the waste could be used to create fuel.

Answer 6

Ahh is this a joke?

You answered your own question.. Corn is used to make ethanol. Used cooking oil is made into Bio-diesel. Never the two should meet. Ethanol and Bio-diesel are different fuels.

Answer 7

biodiesel comes from cooking oil, or other oils (soybean, canola).

bio-ethanol comes from corn, sugarcane, or other crops.

Evan if we reached maximum capacity in producing biofuels, we wouldn't have enough to replace petroleum. If we used only cooking oil we could replace only a fraction.

Ideally, we'd use "flexible" cars that can run on combinations of fuels to make up for it.

Answer 8

A compression ignition engine (diesel) can run best on long chain hydrocarbons (12-20) because of their lubricating properties (diesel, biodiesel, cooking oil, kerosene.)

A spark ignition engine (gasoline powered car) requires the air and fuel be mixed and vaporized on the intake and compression stroke, therefore the fuel must be a hydrocarbon of less than 10 chains long so it vaporizes quickly (gasoline C8H18, methane CH4, ethanol C2H5OH, propane C3H8, natural gas (95% methane)

Therefore only diesels can use cooking oil.  And there just isn't enough waste oil to even supply all that are out there now.

I agree with you, cutting down rainforests to plant sugarcane in brazil to make ethanol is defeating the purpose.  

When the correct enzymes are inexpensive enough to make ethanol out of wood fibers, farmers can "mow" fields of naturally growing grasses to make ethanol.

Best thing about cellulose ethanol is that

1- farmers don't need to plant it (prarie grass is natural)

2- farmers dont need to irrigate it - saves water and energy

3- farmers don't need to use petroleum based fertilizers

4- farmers don't need to spray petroleum based pesticides

5- Its prennial - It will regrow itself every year on its own

Taking out the energy intensive steps required by farmers to make corn ethanol will save a lot of energy and money and make ethanol less energy intensive to produce and therefore less expensive at the pump and better for the environment.

We're almost there.

Answer 9

Milzpergallon has this nailed pretty well.  I have read that oil companies, through thinly veiled think tanks, have criticized alternative fuels the same way that your question does.  Almost always it involves the cost of growing corn to produce ethanol which is a lot of huey as Milz clearly shows.  Ethanol can be made out many different types of plants with one of the most productive being switch grass that grows abundantly completely on its own all over this country and Canada.  Ethanol is not the complete answer but it is part of it.  The pro oil argue that it costs a lot to produce ethanol and so it will not be cheaper and that is something I have heard traditional car lovers repeat. They also put out information that the additional cost of a hybrid will not be realized in gas savings over three years.  In fact the cost of a hybrid model is about the same as adding a power sun roof or certainly the different between AWD and 2WD.   Ethanol is not enough to replace the huge demand for oil in this country but it is one that is very clean to produce and use.  From an eco point of view that is a very big plus.  When I was in the military I attended training on psychological warfare, some times called black ops or propaganda.  It intrigues me that people who are pro ecology have been convinced to embrace the pro oil agruments against alternative fuels such as wind, water and ethanol.  In effect we have pro eco people arguing for oil/fossil fuel energy.  Its quite a trick.  There are many new ethanol refineries in the US and Canada and no new oil refineries working to bring down fuel costs and pollution.  I think it is completely do-able to have wind/solar/hydro produce all electricity in the US that is used for industry, home and mass transit.  Coal can be converted to gas, there are abundant fields of propane and natural gas that can also be used for motor vehicle transportation.  We can do much better, cheaper and cleaner but it is not in the best interest of many powerful groups.  Maybe we have the mojo working now to break this dependency on fossil fuels.  They are almost finished anyhow, let them go.