Solazyme is pursuing an unusual process for using algae to produce liquid fuels including biodiesel. In the Solazyme approach they keep the algae in the dark and feed it sugar.
The new process combines genetically modified strains of algae with an uncommon approach to growing algae to reduce the cost of making fuel. Rather than growing algae in ponds or enclosed in plastic tubes that are exposed to the sun, as other companies are trying to do, Solazyme grows the organisms in the dark, inside huge stainless-steel containers. The company's researchers feed algae sugar, which the organisms then convert into various types of oil. The oil can be extracted and further processed to make a range of fuels, including diesel and jet fuel, as well as other products.
The company uses different strains of algae to produce different types of oil. Some algae produce triglycerides such as those produced by soybeans and other oil-rich crops. Others produce a mix of hydrocarbons similar to light crude petroleum.
I am very interested in algae biodiesel because I think it might turn out as the best approach for doing biomass energy. But most other research groups pursuing algae biodiesel are using photosynthesis where the algae get their energy from being exposed to sunlight. Can the Solazyme approach work better?
Solazyme's approach is supposed to let them use cellulose. So trees, switchgrass and other non-grain crops which can produce more biomass per acre can serve as food sources for the algae. Solazyme avoids the need to build ponds with glass or plastic coverings on a massive scale.
Estimates for how much biodiesel can be produced using the pond approach run into the thousands of gallons per acre per year (one figure: 4000 gallons). One big problem with these approaches is the cost of physical plant structure over many acres. If instead an acre is used to grow switchgrass or trees how many gallons of biodiesel can the Solazyme approach produce?
If anyone can point to some good sources of information on the viability of algae biodiesel please post in the comments.
By Randall Parker at 2008 February 24 11:13 PM Energy Biomass | TrackBackI guess the real question is if the algae can be made to feed on cellulose itself, rather than sugars from cellulosic sources.
O/W, it probably will cost more and be more water intensive and less efficient than gasification.
This also would avoid driving up food prices.
One thing that confuses me about the proposed biofuel solution: If we're still going to burn hydrocarbons, how do we deal with the resulting carbon dioxide in the atmosphere. Or are biofuels just a palliative until a solar-based economy becomes economically feasible?
David,
It will still drive up food prices. Even if they get sawgrass to work, it will compete with other crops for land.
Charlie,
The resulting carbon dioxide will get turned back into cellulose during the next growing season. The carbon in plants doesn't usually come from the soil. It starts out as carbon dioxide in the atmosphere.
"If instead an acre is used to grow switchgrass or trees how many gallons of biodiesel can the Solazyme approach produce?"
Probably not competitive with a pond/solar bioreactor approach, but that's probably OK. Switchgrass and woodchips don't need a big capital investment to get growing; nature is really good at doing that for "free" once you've got some land. I expect that this process is also less energy efficient from a "whole cycle" point of view than a pond/solar bioreactor approach, but again it doesn't matter since the sun's energy is free too; you can waste it to preserve resources elsewhere. I think there's a strong argument that one 10 acre processing plant (using this approach) surrounded by 10,000 acres of switchgrass is more cost effective than 1000 acres of pond reactors. We aren't so short on land yet that it matters.
"It will still drive up food prices. Even if they get sawgrass to work, it will compete with other crops for land."
Maybe, but not necessarily. Arable land suitable for growing wheat, rice, etc. is only a small percentage of total land mass (outside of Kansas and Indiana). Many cellulosic sources can be grown on land that would never be used to grow food crops.
"If anyone can point to some good sources of information on the viability of algae biodiesel please post in the comments."
http://www.oilgae.com/ seems like a good place to start.
Here's a list of companies looking at this space: http://www.oilgae.com/algae/oil/biod/cos/cos.html
I think they'd have a real product there if they engineered the algae to produce desirable omega 3 fatty acids for animal feeds. A varient on silage. That would make it economic with a price per gallon considerably higher than would be economic for fuel.
This is a strange approach. The major point of algal fuels is that algae have far greater productivity than higher plants. Now comes Solzyme, throwing that advantage away. Is it superior to turn e.g. sugar cane into biodiesel rather than ethanol? I don't know, and nothing in the press I've seen about Solzyme even mentions the subject.
Brock,
Competition for the inputs for agriculture will drive up the costs. It's not a maybe. It's a for sure thing. We grow food where we grow it now because we get more of whatever we plant there than if we plant elsewhere. That will be as true for cellulose as it is for any other crop.
We won't be measuring the land for biofuels in 1000's or tens of 1000's of acres. We will be measuring it in hundreds of 1000's or millions of square kilometers.
Algae can learn to metabolize other carbohydrates, or can be grown in bioreactors with symbiotic organisms that break down the cellulose, hemicellulose, lignins, for them.
Still, if you've got the sunlight why not use it? I can see this approach being useful if the sun shuts down, like in the mini-ice age they say is coming. If the sun shuts down, only nuclear and geothermal are reliable.
Is it superior to turn e.g. sugar cane into biodiesel rather than ethanol?
I wondered about that as well. Intuitively, it should, and it should be "sustainable". However, I believe they use the sugarcane bargasse/leftovers (sp?) leftovers to provide the heat for distillation of ethanol. This is probably one of the things that makes sugarcane ethanol EROEI favorable. However, the algae-biodiesel wouldn't need distilling... so the EROEI would probably at least be similar to sugarcane ethanol.
Maybe the bargasse could be pryolyzed and the carbon plowed in instead of using the bargasse for the distillation process.
Then the process could be carbon negative and have a decent EROEI.
Probably not sufficiently scalable, though (unless we all are driving PHEVs).
E-P,
I do not get all the press about Solazyme either. On the one hand they avoid the capital costs of covering an acre with pond bottom and glass or plastic covering. On the other hand, their algae do not even accept cellulose as input. It takes sugar. Where, outside of perhaps Brazil, will it make economic sense to buy sugar for this purpose?
Brock,
Noone has yet found a cheap way to break down cellulose for sugar to ethanol. The same will hold true for cellulose to sugar for algae feed for biodiesel.
To make Solazyme's approach work they are going to need to genetically engineer their algae (or some helper organisms( to eat cellulose.
I get the press.
If one puts out press releases with the right key phrases, one can get on the taxpayer funded gravy train. Who cares if it makes no sense whatsoever? How else is one supposed to make money off a useless product?
It's not like corn ethanol makes any sense either.
As someone who is a supporter of algae-based biofuels, ths approach seems one or two steps the wrong side of stupid. Given that algae will feed on ag run off or other wastes, and enzymes have been developed that can break down cellulose highly effectively, I don't see the advantage.
Studies have shown that open raceway ponds fed by nutrient contaminated water (even brackish water) can produce exceelent yields. One paper on the 'controlled eutrophication of micro algae' modelled the program in a hypothetical scenario at the Salton Sea. The numbers at the time came out at about $US1 per US gallon -- and that was just for the biodiesel.
Algae also yield up starches for alcohol based fuels, the glycerin from transesterifaction can be used in pharmaceuticals, burned as a heating oil, used to run a generator, or added top other waste biomass, converted to syngas and Fischer Tropfed to hydrocarbon fuel. Even the residual salts left from transesterification are a feriliser. Once you spread the income from these merchantables across the whole recurrent cost the price for each of the fuel products is lower still.
Why would you want to increase the money and energy cost of your feedstock and the cost of your capital equipment unless you got truly massive yield advantages?
Fran