One of the reasons ethanol from sugar cane is so much cheaper is because the crop only needs to be planted every 5 yrs, not every yr like corn. That means a lot less tractor time and fuel used per acre per yr.

Another reason is because labor is so much cheaper in Brazil.

I wonder if there is some other thing that would grow real well in our climate from which we could produce fuel more efficiently than corn? Maybe a fast growing softwood?

Excellent points. I'm also certain that Brazil has a longer crop season than America. In America you can only grow crops for a few months per year. In certain parts of Brazil I'm certain it's year-long.

Industrial Hemp.

But this overbloated government, and the oil, pharmaceutical, petrochemical, wood paper, steel, and defense industries that finance it just will not allow it. Even though you cannot get stoned off of industrial hemp, our government still prosecutes people for growing it without a permit the same as if they were marijuana farmers. The catch is, the government has never granted anyone a permit to grow it and refuses to.

They're really pusing this Ethanol
 

There was an Ethanol "awareness" conference at one the hotels in town -- I sort of stumbled across it last weekend. They converted a Lambo, Maserati, 911, Z06, F430, and an Indy Car to Ethanol, and had it on display. It was quite a display, but I didn't have the heart to tell them that each combustion had less potential energy than other, less-polluting alternatives. I'm still not sold on it...

RH77

AH, hemp.... brings me back to my salad days.

Hemp may be a useful fiber, but it's lousy for making liquid fuels. There is a reason that sugar cane and corn are used to make ethanol. Starches and sugars are easy to ferment. On the other hand, hemp, like any other cellulosic material, needs to be broken down into sugars before fermentation. Cellulose is very difficult to break down.

In any case, if cellulosic plants are to be used, the best ones would need little or no chemical nitrogen fertilizer. Some kind of self-seeding nitrogen fixing legume (alfalfa or clover?) would be better than hemp, which needs nitrogen fertilizers (made from natural gas) and which must be planted every year.

Soybeans might be a good choice for alcohol fuel too. Although beans need to be planted every year, you could make biodiesel from soybean oil, and ferment the remaining soybean meal to alcohols.

Talking to a couple from Florida yesterday about this - apparently they can grow sugar cane there and they do. Advantage of corn is the waste is usable - not sure about the sugar cane stalks.

Hemp isn't useful for ethanol.

Biodiesel is where it is exceptionally useful, arguably moreso than soy or other plants.

It needs no fertilizer or pesticide inputs. It can grow in a wide variety of climates, up from the equatorial regions and into Canada. As opposed to helping erode soil like corn often does, it actually replenishes it and helps prevent erosion.

The hempseeds are extracted and crushed to obtain the oil. From that, biodiesel can be made.

Energy Return of Energy Invested is on par with sugarcane ethanol.

Corn ethanol pretty much breaks even with the manmade energy inputs, sometimes takes more energy. Sugarcane ethanol has an EROEI over 5, which is why Brazil is making such wide use of it, it works(although at the expense of rainforest. :().

Hemp produces about 305 kg of oil per hectare. This is about 70 kg less than soybeans, but the overall efficiency is higher than and impact on the environment much less than soy.

It can be grown in arid climates as well, so we won't have to cut down all of our forests to grow it.

***edit***

Please read the following article for a brief summary of hemp as a biofuel:

https://mit.edu/thistle/www/v13/2/enviro.html

Hmmm, I find one sentence in that article highly questionable:

"Hemp does not deplete the nutrients in soil, and even purifies the earth by absorbing heavy-metal contaminants."

This sentence is bunk on two counts:

First, all plants remove potassium and phosphorous from soil. If hemp is harvested and processed off site, those essential plant nutrients eventually will be depleted from the soil. And since hemp is not a nitrogen-fixing legume, the same holds true for soil nitrogen. Remember the Law of Conservation of Matter? "Matter can neither be created nor destroyed".

Second, if hemp absorbs heavy metal contaminants, then the hemp itself will contain it. Processing it for fuel or burning it will either disperse it into the air will create an emission or waste disposal issue. I suppose that one could put those heavy metal back into the fields from which they came, but where is the benefit claimed?

Such inconvenient truths detract from the article's credibility. Have you actually read the references to see whether the other assertions in the article are supported by research? Maybe the authors smoke too much.

The amount of nutrients it requires is so low relative to that of other plants, that it is perfectly feasible to plant hemp on the same plot of land for nearly 15 years in a row, without any crop rotation needed and without soil erosion resulting.

Historically, farmers used to use hemp to prepare their soil for more demanding crops, like wheat or corn.

Most of this is due to the roots remaining in the soil and containing much of the nutrients, leaves falling off of the plant, mostly returning the nutrients taken back to the soil, before it is even harvested.

Hemp will need roughly 150-170 kg/hectare of potassium, but the vast majority of it, ~70-95% depending on many factors, will be returned to the soil before the seeds and fibers can even be harvested. Even more nutrients can be reclaimed by returning unused trimmings to the soil.

The benefit comes from being able to use hemp plants as a means to absorb heavy metals, and soley for that use. They don't have to have multiple purposes with the same crop. It's easier to collect such toxins within plant matter itself, than to try to manually clean the soil of such heavy metals.

I've read some of them, but haven't had the time to scour them all. Not yet anyway. I have read studies not mentioned in this article that do support its thesis.

Not that there's anything wrong with that. ;)

https://www.fromthewilderness.com/fre...questions.html

"Ethanol is another case in point. Some research has shown a negative EROEI for ethanol. Newer research from Oregon shows a slightly positive return. Ethanol is, at best, a slightly beneficial temporary alternative - not a substitute."

Ethanol is a subsidy for farmers and Cargill?

https://www.eroei.com/eval/net_energy_list.html