Tuesday, April 05, 2011

What is Dr. Pfromm Missing When He Says Algal Fuels are Doomed?

[Peter]Pfromm and K-State researchers Vincent Amanor-Boadu, associate professor of agricultural economics, and Richard Nelson with the Center for Sustainable Energy conducted an in-depth analysis on algae biodiesel production. Their first algae-related nonprofit study, "Sustainability of algae derived biodiesel: A mass balance approach," supplied the cover picture in a recent edition of Bioresource Technology, a peer-reviewed journal. _Eurekalert

Pfromm and his colleagues came to the conclusion that it is impractical to make biodiesel from algal oils, due to the physics of limited available sunlight, and the chemistry of limited available carbon and CO2 feedstock. These limitations -- and other shortcomings pointed out by Pfromm et al -- make the production of algal biodiesel a difficult uphill battle. The authors criticise economists who promote algal fuels, for focusing entirely on the financials, and not looking hard enough at the physics, chemistry, and microbiology of the process.

And yet, it seems as if Dr. Pfromm and his colleagues may have missed a few things regarding the algal fuels picture themselves. There is no doubt that the energy equations must balance, as must the chemical input and output equations. And there are certainly huge problems involved with both the open pond (or raceway) approach to algal farming, as well as the closed bioreactor approach. It is likely that it will take at least 5 years, and possibly 10, to solve these problems well enough to make algal fuels competitive and ready to scale up.
Algae2020 PDF

Dr. Pfromm is not alone in his pessimism toward algae. Many photosynthetic fuels researchers have turned away from algae toward cyanobacteria, and other engineered bacteria. That is because bacterial DNA is easier to access and manipulate than algal DNA. Other microbial fuels researchers have turned away from sunlight and CO2 altogether -- in favour of a feedstock and energy supply from biomass sugars.

Any photosynthetic fuels maker trying to feed his microbes with atmospheric CO2 and sunlight alone is doomed to fail. Photosynthetic microbes need a lot more carbon than they can get from the atmosphere (a mere 0.04% CO2). But cement plants and fossil fuel burning power plants provide copious amounts of CO2 which can be pumped into growing environments for microbes. And sunlight can be augmented by artificial light to enhance growth.

But the biggest thing that Dr. Pfromm and other algal skeptics seem to overlook time and time again, is that the early profits from algal fuels will not likely come from algal oil biodiesels. The early profits will come from the prolific biomass potential of algae.

Sure, eventually it will be economical to separate the lipids, proteins, and carbohydrates in order to best utilise the individual components of algal mass. But in the early stages, the algal biomass itself is the high-value crop. Micro-algae and seaweed (macro-algae) are most prolific, compared to land crops.

Growing algae for biomass, rather than for lipids, allows for much more economical and less fastidious growing methods and harvesting techniques. Locating algal biomass farms near sources of wastewater and waste CO2 allows for low-cost feedstock which can be converted quickly and economically into algal biomass. Omitting the lipid separation step streamlines the process in many ways.

Once you have the biomass, you can choose from a wide variety of methods for converting the biomass to either energy, fuels, or high value chemicals. Gasification to syngas allows for direct power generation using gas turbines, conversion to hydrocarbons via catalytic synthesis, or fermentation to alcohols and other chemicals. Pyrolysis can be even more economical, allowing the elimination of the potentially expensive drying step -- using simple straining and filtering instead.

Thermochemical (and fermentation) conversions of algal biomass to energy and fuels can take advantage of the more advanced state of development of those approaches, compared to more direct microbial fuels. Eventually, algae and other microbes will become more economical for production of fuels than the thermochemical and fermentation approaches to biomass treatment. When that happens, the industry will shift in that direction -- as the economics dictates.

Dr. Pfromm and his colleagues make some excellent points which microbial and algal fuels researchers must necessarily deal with. But they will do so successfully, in time. In the meantime, it is best to follow a logical progression in these things, as nature, science, and technology allow.

Top 10 Algal Biofuel and Biochemical trends from 2011 to 2020

A French-Spanish project to develop large scale algal fuels in closed tube reactors

One way Sapphire Energy manages to stay in the algal fuels race when so many other companies have fallen by the wayside

Learning to produce algal fuels at a cost of $94 a barrel: Not good enough, Sonny Jim! But moving in the right direction.



Blogger Gene said...

Another thing that this study seems to take as read is the assumption that algal biofuels will be deployed as a full-scale replacement for current liquid fossil fuels. I'm on board with the 'silver buckshot' approach, and I can imagine a future in which most mundane, short-range travel is accomplished via FCVs, hybrids or full electric vehicles ( maybe with a little help from an built-up public transportation infrastructure), while algal fuels and similarly energy-dense liquid fuels are set aside to do the heavy lifting applications, like aviation, trucking and sea freight. I'm just a concerned layman, not a chemist, engineer or economist, but presumably this broadened approach to energy solutions would ease the pressure off the scalability issue. Thoughts?

7:22 PM  
Blogger al fin said...

Gene: It is very true that scientists and technologists are taking many different approaches to replacing petro-fuels, and reducing reliance on fossil fuels.

In the short term -- the next 20 years -- it will be very important to find liquid fuel replacements for crude oil distillates.

Unconventionals such as oil sands, oil shale, gas to liquids, coal to liquids, heavy oil etc. will all come into play. But microbial and biomass fuels are also likely to become important due to the ability to produce them almost anywhere -- particularly as their production becomes more scalable and standardised.

An electric vehicle infrastructure will require a lot more dependable baseload power plants, chains of quick charging stations, and much better batteries and / or super capacitors. No one knows how or in what form all of that will shake out.

Of course there is always the green "dieoff.orgy" approach, where 90% of humans are eliminated, leaving the planet to the remaining 10%. But that is just trading one big set of problems for an even bigger set of problems. Not to mention taking a horrifically immoral action under the pretense of saving the planet -- a planet that in the best analysis doesn't need saving by humans, except perhaps from an asteroid strike.

7:49 PM  
Blogger Gene said...

Of course there is always the green "dieoff.orgy" approach, where 90% of humans are eliminated, leaving the planet to the remaining 10%. But that is just trading one big set of problems for an even bigger set of problems. Not to mention taking a horrifically immoral action under the pretense of saving the planet -- a planet that in the best analysis doesn't need saving by humans, except perhaps from an asteroid strike.

To be fair ( and I'm not sure I'm talking to the same people you are), I'm not sure that mass starvation and death are thought of as part of the plan. My understanding was that the Malthusian catastrophe scenario was more thought of as a consequence, rather than a desired outcome.

Full disclosure: I might be what you would call 'green', and I can state quite unconditionally that I have no desire in seeing 90% of our species die. Perhaps that would explain my enthusiasm for expansion and innovation in nuclear energy (seemingly a minority opinion among my fellow liberals, especially these days).

My big concern is subsequent generations. I'm expecting that we'll encounter a bit of an energy bottleneck in the coming decades ( no, in case you're wondering, I'm not a peak oil doomer; perhaps a peak oil fretter), but my wife and I are looking at the prospect of children in the not-too-distant future, and I'd like for him/her/them to have a quality of life that's at least in the ballpark of the one I enjoy, and for my child/ren to be able to leave subsequent generations in equal or better condition, and so on. For this reason, I think that methods need to be discovered and perfected so that all energy is ( or can be made to be) renewable, rather than dependent on finite resources.

Anyways, thanks for the work you do here. It's always an interesting read, even in the places where I disagree with you.

9:40 PM  
Blogger al fin said...

There is certainly room for many viewpoints along the way. I myself have owned most of them at one time or another. ;-)

My main informers on the green movement are members of the radical left enviro / anti-capitalist groups residing mainly in the North American Pacific Northwest, and along the Eastern Seaboard within particular enclaves of leftist insularity.

I take them as representative because I see such a strong reflection of their views in the actions, pronouncements, and recommendations of mainstream greens in the media, in popular culture, in the current US government, and in academia across N. America, Europe, and the Anglosphere.

5:51 AM  

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