What Are the Shortcomings of Converting All Used Cooking Oil Into Biodiesel?

[Ivan Seeking]

Klimatos, after giving up the effort due to the excessive development costs, I spent about eight pages [intermittantly] explaining the concept and reasoning used in our approach. In my opinion we made a number of gains, not the least of which is possibly eliminating the need for a nitrogen source. If you, she, or anyone else is interested, I summarized some of our efforts and findings beginning approximately on page 14 of this thread.
https://www.physicsforums.com/showthread.php?t=211274&highlight=algae+rescue&page=14

 

[DoggerDan]

All in all, biodiesel is not a good fuel option unless it can be produced from algae.

Now you're talking.

When taken from standard crops like soybeans, cotton, palm, etc, the return per acre-year is almost as bad as ethanol, which is ridiculously low. The key is to pursue the algae option and similar technologies that offer twenty times the yield per acre year, or more, as compared to ethanol.

Now you're really talking! Any mention of wide-spread use of ethanol tends to drive food prices way up, even though our government still pays many farmers not to grow things on their land.

Algae biodiesel is also known as oilgae (http://www.oilgae.com/), at least by one company's reckoning.

Couple of quotes from Wikipedia:

"The United States Department of Energy estimates that if algae fuel replaced all the petroleum fuel in the United States, it would require 15,000 square miles (39,000 km2) which is only 0.42% of the U.S. map. This is less than 1⁄7 the area of corn harvested in the United States in 2000."

I wonder if that's less than the area of corn which government pays farmers not to grow.

"According to the head of the Algal Biomass Organization algae fuel can reach price parity with oil in 2018 if granted production tax credits."

Since tax credits come out of the taxpayers pockets, let's skip this step and simply pay for what you use.

Then biodiesel could virtually eliminate the need for petro.

Only if you own a diesel. Looks like I'll be going diesel sometime in the future.

And best of all, it is carbon neutral.

Not really. You're still producing more carbon to grow, harvest, transport, and burn it as a fuel than it sequesters.

Unfortunately, most biodiesel crops don't produce much better than corn.

You're saying the DoE's figures are out to lunch? Wikipedia's source on that was: Hartman, Eviana (2008-01-06). "A Promising Oil Alternative: Algae Energy". The Washington Post.

 

[Ivan Seeking]

Not really. You're still producing more carbon to grow, harvest, transport, and burn it as a fuel than it sequesters.

How does that happen if the system is effectively closed - self-powered? I think you are assuming the general model in place now, and not a more practical model like the one I describe in the thread linked.

You're saying the DoE's figures are out to lunch? Wikipedia's source on that was: Hartman, Eviana (2008-01-06). "A Promising Oil Alternative: Algae Energy". The Washington Post.

I was referring to options other than algae. At about 500 gallons of fuel per acre-year - at most 20% of the yield of algae - palm is I believe the next best producers. Soy and rapeseed are down around 100 gallons per acre-year.

 

[Ivan Seeking]

Oh yes, over a total of 9 months of testing - 3 months indoors and then 6 months indoors and outdoors - my algae water never acquired an odor. When it was harvest time, the stuff looked like pea soup, but at most there was a slight odor of vitamins due to the nutrients used. The unpleasant odor klimatos mentioned indicates the presense of bacteria, which immediately means reduced yields or even the death of the algae bloom. This goes back to the point that the problem of contamination makes open ponds impractical.