Making biofuels from seaweed is one of the latest ideas for creating sustainable fuels that don't compete with food crops. Two different teams, one US-led and one in India, are working on solutions.
By growing on the surface of the ocean and using nutrients that derive from saltwater, seaweed as a feedstock is highly scalable yet avoids several problems associated with crops on land: competing with food crops for fresh water and arable land, and requiring fertilizer. Seaweed, a form of algae, is already cultivated around the world as a cheap form of food. It reproduces easily and is high in carbohydrates. However, because its chemistry differs from that of land plants, it requires a different type of process for converting them to sugars that can then be used for producing ethanol.
One of the latest ideas for creating sustainable fuels that don't compete with food crops is making feedstocks from seaweed, such as this red seaweed (Plocamium sp.). (Source: Wikimedia Commons/Derek Keats)
In Chennai, India, Sea6 Energy is working on a process that not only converts red seaweed (Plocamium sp.) to liquid fuel, but uses sea water for the process steps instead of the large quantities of fresh water used in converting agricultural crops to biofuels. That fresh water requirement is a major problem in drought-plagued areas of the world such as India, and is becoming a potential problem in traditionally more well-watered areas like the temperate zone US. The company's fermentation process reportedly uses regular yeast to digest the seaweed's carbohydrates without requiring the use of genetically engineered bacteria, more common in many seaweed-to-fuel conversion attempts.
Red seaweed is among the most productive seaweed species, and already used for other purposes, such as in the production of cosmetics. Sea6 Energy is focusing on improving seaweed cultivation methods, which have remained labor intensive, to scale up production and boost yields even higher. The company's engineers have developed proprietary structures that could extend seaweed farming beyond the shallow waters where it currently takes place, to more extreme environments in rougher seas.
In the US, the research team, led by BioArchitecture Labs, is investigating the combination of engineered bacteria with brown seaweed. In a paper published in Science, the team describes its process for converting the sugars in seaweed into ethanol by genetically engineering a bacteria that can digest them. The team's researchers say their process "enables bioethanol production directly from macroalgae via a consolidated process, achieving a titer of 4.7 percent volume/volume and a yield of 0.281 weight ethanol/weight dry macroalgae (equivalent to ~80 percent of the maximum theoretical yield from the sugar composition in macroalgae)."
A commentary in the same issue of Science points out that seaweed would have to be grown on more than 11,000 square kilometers (2.718 million acres) to produce enough ethanol to replace only 1 percent of the current US gasoline consumption. For comparison, a total of about 80 million acres of corn are currently grown in the US. As we've pointed out in blogs and several comment discussions on Design News posts, it's unlikely that any one sustainable and alternative fuel and energy source will single-handedly replace petroleum-based sources. Instead, it will likely take a mix, since they're not all created equal.
I, you can make as much syn gas as you want by heating yard wastes, etc to 1500F to get H2 and CO/syngas. So H2 is not expensive or hard to get.
There is plenty of waste here in Fla for free and they'll even pay you to take it!! Plus crop, forest wastes makes growing seaweed an expensive choice, source.
What is needed is a eff way to convert it to liquid fuels. anyone know a viable process? FT is so so because it wastes too much in CO2 and waste heat production though the heat could be turned into electricity.
Can one heat woody biomass with H2 under pressure and get sellable, useable HC's especially liquid ones preferably from propane to medium gasolines?
- CAFE standards are not the answer, especially since vehicles that meet these standards aren't for everyone. I'm glad that fuel effecient vehicles are available, but I surely don't want the government forcing me into a small, underpowered car. I lived through the results of the first Carter administration, and am now living through the second Carter administration. ;)
- Ethanol. What's the point? It absorbs water and can't be transferred via pipeline, is harmful to the fuel systems of most vehicles, and decreases MPG. Then you have the government subsidies and all the garbage related to that, and the effects of diverting food crops to energy production. I'd love be able to buy straight gasoline, but it's no longer available in Pennsylvania.
I think the answer might be related to technologies that can convert feedstocks directly into gasoline and diesel, like this:
- As for the smart grid, I have no desire for that at home. I actually implement DR (Demand Response) and SR (Synchronous Reserve) programs as a part of my job, and while it's a nice extra money saver for participating companies (the power company pays us to drop our load) at home it would just be uncomfortable. I don't want the power company telling me that I need to turn off my heater or air conditioner at home, especially if I wasn't being paid nicely for it.
Alternative energy is one of the industries Design News covers. I think Nadine's points are well taken about using less energy. Americans have been wasting it for decades, compared to the simpler lifestyles of some other people on the planet. It's also the case, as we've mentioned several times in articles about alternative energy sources, including this one, that the model for these is quite different from the mono-model for petro-based fuels: "it's unlikely that any one sustainable and alternative fuel and energy source will single-handedly replace petroleum-based sources. Instead, it will likely take a mix." A parallel mix of strategies are going into efforts like the CAFE standards, as Chuck's slideshow showed: http://www.designnews.com/author.asp?section_id=1366&doc_id=250882
NadineJ, you are exactly right. In the electrical realm this has been happening. Thus, you hear about a paradoxical situation in which rates may go up because people are using less. This is due to the high fixed costs of electricity.
In the transportation fuels area we have a real problem. The new CAFE standards are important. The fact is that, all complaining about gasoline prices aside, many people still drive cars that get horrible gas mileage. We recently had to replace our ten year old minivan. My wife was looking at all the alternatives and ended up getting a small sedan. Well, I heard her say the other day, as a large SUV went by, that those people were driving a car that got about 10 MPG in the city. That's what large cars got in the 1970s.
In the electicial utility world they call it Demand Side Management (DSM). It was done with large customers first. With SmartGrid technology it is being extended to households. This includes information about usage, and variable pricing. Perhaps we need to do something along those lines for automobiles.
Maybe, look at it from a different angle. Instead of creating massive amounts of energy, let's decrease our usage. Low yields wouldn't be as much as an isuue. The possibility of local production would make a big difference as well.
Jimmy Carter was criticized for telling America to "put on a sweater" when it's cold instead of turning up the heat. If we'd done that 30 years ago, we wouldn't need so many other energy options today.
Ann, that is the problem with all these alternatives, low yield. To make ethanol you need sugars! The best feedstock is sugar cane. Corn is a reasonable alternative, but not as efficient. I find it interesting that you have all these articles about alternatives, here in Design News and elsewhere, and yet none of them amount to more than a few percent of what is needed. Remember when President George W. Bush started talking about switchgrass? He was roundly criticised. Well, I have heard the Obama Administration talk about it. Recently, the new fad was algae.
In any event, an organic alternative will always have effects on the ecosystem. Large scale cultivation, I mean large enough for energy needs, will have an effect on the oceans. Whether this is good or bad, I do not know, but it will have an effect.
Inspired by the hooks a parasitic worm uses to penetrate its host's intestines, the Karp Lab has invented a flexible adhesive patch covered with microneedles that adheres well to wet, soft tissues, but doesn't cause damage when removed.
Engineers at the University of California, San Diego are designing a robotic arm that takes inspiration from the loose, flexible, yet very strong structure of the armored plates on a seahorse's tail.
Researchers at the Missouri University of Science & Technology have designed a new nanoscale material that can transmit light faster than the 186,000 miles per second it usually takes to travel through air.
It has often been said that as California goes, so goes the nation. This spring, the state's wind power is setting energy generation records and solar energy generation is expected to rise sharply during the second half of 2013.
The latest model of Liquid Robotics' Wave Glider autonomous, unmanned marine vehicle (UMV), the SV3, is reportedly the world's first hybrid wave- and solar-power-propelled unmanned ocean robot.
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