Algae to Ethanol - The Hows and the Whats...

Algae to Ethanol - The Hows and the Whats...

Postby cacofonix » Mon Aug 18, 2008 10:02 am

This was something I discovered I had posted a long while ago in the Oilgae Blog ( )...but I must admit I have not done a lot of research in ethanol production from algae...

But just read this...(source link - ... hanol.html )

"He further says: "I can see many advantages to make ethanol from algae instead of diesel:
1.The lipid (oil) content in algae (best strains I have seen from different sources max. 70%) is less than starch+cellulose+ sugars(nearly 100%) content
2.Algae should be dried (a lot of energy) to extract oil but needs no treatment for ethanol fermentation
3.Extracting the oil from algae is complicated
4.CO2 from ethanol fermenting can be used as algae feedstock
5.The energy from fermenting and distilling can be used to heat algaeponds (photobioreactors) in cold climate."

Do any of the members have a good idea of the algae to ethanol processes and do we have real-world information on this?


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Re: Algae to Ethanol - The Hows and the Whats...

Postby chennai102 » Tue Sep 02, 2008 5:25 am ... check.html

frankly i would be greatly impressed if anyone out there can get 70gal of clean, pump ready ethanol/ton of biomass. this would be a major improvement to the ~9gal/ton that exists now before adding all the costs to grow, transport, process and pump it.

a typical ton of biomass = ~13mBTU.

a typical gal of ethanol = ~75000BTU.

even at the 'theoretical limit' is reported to be 114gal/ton x 75000 = 8550000/13000000 = 65% of the energy is somehow wasted and this is the theoretical limit. so lets say that they can only do 75% of the limit due to 'conditions on the ground' = 85.5gal/ton would be a target #. so real world target would = 6412500BTU harvest/ton. less than 50% energy return on feedstock.

going further down the energy chain, we have the inefficiency of the combustion engine. ~ 25% efficient. and because of regulations of emissions and the gadgets that are needed to reduce pollution, that 25% is further reduced by 10%. i wont even add in coldstarts, the energy to make the motor and the lifespan of said motor and all the other inefficient ways that this system sux. we are now down to ~11%. so 11% of the energy from the original biomass is actually used to do actual work. and i have rounded up, infavor of the benefit of the doubt.

by the way, transportation fuel is only 25% of all the BTU's used by the USA. the elephant in the room is coal. ethanol does nothing for that but we seem to have already used up all the farmland...

the beauty of cellulosic ethanol is that all cellulosic biomass can be used. the curse of cellulosic ethanol is that ALL cellulosic biomass can be used. what is going back into the soil? how long before the rainforests are harvested for biomass energy? how long before everysquare inch of land is being sucked of energy and life by humans?

there is 2 solution to this mess. 1, figure out a better way to extract energy outta the feedstock (which ethanol cannot do because of its limitations). 2, to produce MASSIVE amounts of cellulosic biomass/acre so that the inefficiencies of the harvesting energy outta the feedstock is mitigated. in walks algae...but the infrastructure needed to ramp that kinda production is so very far down the road.

so in summery; i am very sceptical of the 70gal/ton Iogen claims. and even if they are correct, this still doesnt solve the problem that the world has. and the closer it becomes to being a reality, the worse the earth groans... i agree, cellulosic ethanol is 'snake oil'!
Those that live by the sword, die by the sword. Id rather die of cholesterol from all the butter Im making and selling... froggy in Wisconsin

This is an interesting blog and the two of them are pretty serious about ethanol from algae. Read more at
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Re: Algae to Ethanol - The Hows and the Whats...

Postby chennai102 » Fri Sep 12, 2008 4:07 pm


Company uses algae to make ethanol more eco-friendly

Corn-based ethanol is getting slammed for straining the world's food supply and contributing to global warming by encouraging the plowing of grasslands.

Cellulosic ethanol, a more eco-friendly version derived from switch grass or wood chips, is several years away. Maryland-based Algenol says it can solve the problems by making ethanol from algae, starting next year.

The start-up recently agreed to license its technology to BioFields, which plans to build an $850 million saltwater algae farm in Mexico's Sonoran Desert and churn out 100 million gallons of ethanol the first year. It will sell the gasoline substitute to Mexico's state-run oil monopoly.

A handful of companies are working on turning the abundant marine organism into biodiesel. That requires growing algae and killing them to extract their oil, a time-consuming and expensive process.

Algenol adds enzymes to the organisms to enhance their normally limited ability to convert sugar into ethanol, a waste product. To maximize ethanol production, the algae are placed in regions with abundant sunlight and grown in 50-foot long tubes filled with seawater. Ethanol is captured as a gas in the bottle and condensed to a liquid. Since algae aren't destroyed, the same ones keep yielding ethanol, holding down costs.

Algenol CEO Paul Woods says production costs are half those of corn-based ethanol, and the fuel will wholesale for $1 less than gasoline. His goal: Woods wants to build 20 plants in sunny areas such as Texas and Florida to generate 20 billion gallons of ethanol by 2020. "We don't have any limitations, because we're not competing with the food supply," Woods says.

Philip Pienkos, of the National Renewable Energy Laboratory, says Algenol's goal is "definitely doable." But he says there will still be a need for fuels with higher energy content than ethanol.

This article is from usa today - ... ment_N.htm
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