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THE Algae Thread pt 3 (merged)

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THE Algae Thread pt 3 (merged)

Unread postby davep » Sun 19 Jul 2015, 11:29:00

Essentially we are eating and being powered by the Sun. Turning the incident insolation into biomass by photosynthesis is a thermodynamic process that has certain limitations. The wavelength of light absorbed. Respiration of the living cell, energy consumed in converting carbohydrates into proteins and lipids, all increasing the entropy of the universe. That is the fundamental principle of thermodynamics. Entropy has to increase. A reduction in entropy in one system has to result in a net increase overall elsewhere.


My point is that this reduction in entropy has no impact whatsoever over the next few hundreds of million years as the source of energy is the sun. And if normal algae can thrive in that environment the problem is not generic, but specific to the strains they're trying to grow for oil. Hence it is not a thermodynamic problem, but a biological adaptation problem (as you suggest further on).

Algae has evolved over billions of years. Making it function even better will be a daunting task, because by natural selection the best configuration for the current environment has probably already been achieved. It might be possible to engineer small gains in certain functions but fundamentally improving the yield from photosynthesis is highly improbable due to the thermodynamics of the z-scheme or Calvin Benson cycle, whichever you prefer.


There are plenty of scenarios where e-coli, for example, is genetically engineered to produce stuff. So the problem is not trying to squeeze more out of natural selection, but to change the levels of production of oil for algae (which is not something that natural selection has required). This doesn't necessarily need an improvement in photosynthesis (as strains have been created that can do it), being a problem of creating a viable strain that can reproduce and thrive anywhere near as well as standard algae.

Yes, thermodynamics is behind everything energy-wise. No, it isn't responsible for the problem with algae biofuels.
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Re: THE Algae Thread pt 2 (merged)

Unread postby isgota » Sun 19 Jul 2015, 12:23:29

The limiting factor right now for photosynthesis is CO2 and/or NPK. Photosynthesis has a theoretical limit of about 11% and a practical one of about 5%. Plants and algae in the wild get about 1% conversion because CO2 concentration in atmosphere is low.

So actually you can get improvements on energy captured introducing CO2 in algae cultures.

But this is not easy to do. You must build a cultivation system that is good for algae productivity and cheap enough at the same time.

R&D for algae fuels have shifted lately, almost nobody search getting oil to make biodiesel (or if they do it, it's a secondary product not the main one). Right now, the targeted technologies are direct excretion of products, thermal conversion of whole algae or even both at the same time.

In my opinion the nearest to a commercial scale is Algenol, but even they say there is still a lot of work to do:

The goal is to announce the name of the facility this spring and break ground this year. Algenol wants to eventually expand to 8,000 acres of algae-producing modules, with a target production of 8,000 gallons of ethanol per acre, per year, or about 64 MMgy. “We’re not there yet,” he says, adding that the project is currently in the planning and engineering phase. “We’re really evaluating all of the costs and making sure that it really can be done on this land. There’s a lot of moving parts.”


Time will tell if the numbers match.
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Re: THE Algae Thread pt 2 (merged)

Unread postby Carnot » Sun 19 Jul 2015, 14:11:03

Davep,

Sorry it is a thermodynamic issue. The theoretical photosynthesis limit will never be achieved and tailoring the organism (whatever it is) to produce more lipids comes at a price. Carbohydrate has an energy of roughly 16 MJ/kg whereas lipids will be of the order of 35MJ/g Remember you cannot win (except if you are Graeme) so any increase in lipids comes with a reduction in mass and losses due to entropy. Lipids being low er entropy require energy to be consumed to increase the overall entropy of the universe.

Isgota has suggested the thermal conversion of the whole algae but my personal view is that this will still be difficult to achieve a significant net energy gain, which is what it is all about. As for the excretion of fuel products I, and others , remain sceptical.

Isgota has quite rightly brought up the consumption of CO2 as a rate limiting factor. I totally agree, but the source of CO2 really needs to be concentrated. Flue gas for instance.If you use a closed system then oxygen builds up and inhibits photosynthesis. I tend to disagree that it is just the concentration of CO2 that limits photosynthesis. Temperature, photon density, and photo-inhibition all have a role to play, as do the pH. dissolved solids and NPK levels. The there is also the issue of shading. Plenty to screw it all up, and that is before we consider monocultures.

We will still be debating this subject in 20 years time and there will still be no viable commercial algae fuel. I will bet money on it.
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Re: THE Algae Thread pt 2 (merged)

Unread postby Graeme » Sun 19 Jul 2015, 17:15:06

No it's not. You just ignored what I posted:

The potential of microalgal biofuels will be realized only by addressing the real issues of productivity, strain selection and efficient use of resources in large-scale production facilities.


The NREL in 2010 (their executive summary, page iii):

Commercial algal growth will require the development of strains and conditions for culture that allow rapid production of algal biomass with high lipid content and minimal growth of competing strains.


And this highlighted on page v:

The production of liquid transportation fuels from algal biomass is technically feasible. However there is a need for innovation in all elements of algal biofuels production to address technical inefficiencies, which represent significant challenges to the development of economically viable large-scale algal biofuels enterprises.


As well as this from European Algae Biomass Association:

"Algae and aquatic biomass has the potential to provide a new range of "third generation" biofuels, including jet fuels. Their high oil and biomass yields, widespread availability, absent (or very reduced) competition with agricultural land, high quality and versatility of the by-products, their efficient use as a mean to capture CO2 and their suitability for wastewater treatments and other industrial plants make algae and aquatic biomass one of the most promising and attractive renewable sources for a fully sustainable and low-carbon economy portfolio."


If we are still debating this in 20 years time, does that mean you really think that algae biofuels are viable? A Freudian slip perhaps?
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Re: THE Algae Thread pt 2 (merged)

Unread postby StarvingLion » Sun 19 Jul 2015, 18:01:51

Carnot does not understand the simplest system: solar powered water splitting. No one does. So why complicate the situation by tackling a complex machine such as Algae? What the hell can be said about that?

There is a huge basic science deficit that nobody wants to recognize. We aren't getting anywhere by doing experiments.
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Re: THE Algae Thread pt 2 (merged)

Unread postby Graeme » Sun 19 Jul 2015, 18:13:07

The problem is not that biofuels can be produced from algae but that this can compete with FF economically and produce the volumes required (quote from NREL report linked above, page 88).

A 50% contribution of algal biofuels to predicted 2030 biofuels production would require the construction of 1700 100 ML facilities. Clearly, this is beyond the growth rates experienced by the biofuels industry in the past several decades and it would require very concerted effort industry and government to achieve by 2030. Beyond this timeframe, algal biofuels may make even greater contributions to liquid fuel supply. Certainly the analysis reported here suggests that large scale algal biofuel productions may eventually become economic viable.
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Re: THE Algae Thread pt 2 (merged)

Unread postby vtsnowedin » Sun 19 Jul 2015, 18:43:50

Once again people have lost sight of the fact that algae derived fuels don't need to suddenly replace 80 mpb of crude oil and condensate. They need to replace the gap between declining production minus efficiencies that can be achieved and will be as soon as a shortage drives up prices. Filling that small gap even at $20/gallon will do just that. Fill the gap.
Acreage of ponds and water devoted to growing the algae along with the other resources required can start out small and grow at the rate the gap grows.
I don't think algae fuel will ever be the dominate source of energy in my lifetime or even in the century after I'm gone but as a way to convert sunlight into liquid fuel where other supplies have gone missing I think it will play an increasing role as time goes on.
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Re: THE Algae Thread pt 2 (merged)

Unread postby Graeme » Sun 19 Jul 2015, 18:58:04

Fill the gap is a good point. Thanks.
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Re: THE Algae Thread pt 2 (merged)

Unread postby Graeme » Sun 19 Jul 2015, 22:45:58

What's wrong with vtsnowedin's point?
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Re: THE Algae Thread pt 2 (merged)

Unread postby davep » Mon 20 Jul 2015, 03:23:21

pstarr wrote:Photosythesis has it physical limit, the level of production of algae has been coded into their genes by billions (not millions) of years of evolution and yes simple thermodynamics. We are not gods. Geneticist are not gods.

davep, you need to study the commercial application of bioengineering among higher plants and animals (not bacteria/yeast/virus). There have only been two really commerically successful products over almost 35 years. It is mostly a failure. We have never coded a higher plant or animal to our purposes. And yes, a simple photosynthetic organism is a very complex organism compared to a yeast.


Where have I suggested photosynthesis doesn't have limits? Yet despite this limit, walnut and olive trees produce prodigious amounts of oil. So it is not a limiting factor in itself.

The bioengineering is hard, that's what I've been vigorously agreeing with. The high entropy is an attempt at a solution for current strains rather than a root cause for the strains being non-viable. So, again, it's not a thermodynamics problem (although that is part of the current attempts at a solution), it's a biochemical/bioengineering problem.

As for carnot's argument that lipids are higher calorific value than carbohydrates, of course they are. That's half the point. But creation of lipids needn't necessarily come at the price of overall function if they just decrease reproductive rates (so that the energy for asexual or sexual reproduction is offset over time for lipid production). This is where a viable lower-yielding strain would be useful (rather than some super strain that produces huge amounts of lipids yet is not able to reproduce). But I agree that we may never find such a viable strain.
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Re: THE Algae Thread pt 2 (merged)

Unread postby Carnot » Mon 20 Jul 2015, 12:37:15

Fill the gap. My goodness why did I not think of that.

It might fill a gap as thick as a fag paper. The grand master has spoken.
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Re: THE Algae Thread pt 2 (merged)

Unread postby davep » Mon 20 Jul 2015, 15:48:06

Carnot wrote:Fill the gap. My goodness why did I not think of that.

It might fill a gap as thick as a fag paper. The grand master has spoken.


I was just stating why I don't think it's primarily a thermodynamics problem, and suggested a more sustainable approach (which probably won't work either). So instead of ad homming, how about responding to my argument in some way? I'm not having a go at you personally. I'm just interested in the subject too but happen to disagree with this point.
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Re: THE Algae Thread pt 2 (merged)

Unread postby ennui2 » Mon 20 Jul 2015, 16:29:50

pstarr wrote:/sarc


Let's face it, pstarr. There is no close-tag on your sarcasm.
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Re: THE Algae Thread pt 2 (merged)

Unread postby Graeme » Mon 20 Jul 2015, 17:55:45

Davep, I think Carnot was having a go at me. I'm not exactly sure what vtsnowedin meant but my view is that as algae biofuels become cheaper and increase in volume, they ought to be able to take advantage of oil price spikes and sell when oil is high. As time passes, the effect that biofuels could have on the market will be to dampen price volatility and reduce oil exploration because the oil price would stay low.
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Re: THE Algae Thread pt 2 (merged)

Unread postby Carnot » Tue 21 Jul 2015, 05:14:08

Davep,

Grame was correct. He is such a genius with his "fill the gap" point.

I have explained the thermodynamic position before but few people read it and even fewer understood it. I even gave references to several papers, one by David Walker, who was one of the pioneers on photosythesis research, who worked with Hill. Sadly his paper, Biofuels: facts, fantasy and feasibility is now behind a paywall, but if anyone wants a copy send me a pm and I will send it to them.

I think we can all agree that there will be rate limiting steps in any process, and that energy cannot be created from nothing.

For photosynthesis the absolute limit will be a function of the incident insolation, which varies throughout the year and latitude.

Photosynthesis generally absorbs radiation in two bandwidths 440-450nm and at 680 nm which drives the z scheme of the Calvin Benson cycle. Theoretically 8 photons of light energy are required to produce one CH2O carbohydrate unit; in reality the number is between 9-10.

Now assuming that the other factors, listed below are within range it is this reaction that sets the theoretical maximum yield of carbohydrate units. The other factors are:

1. Light intensity (high and low)
2. CO2 concentration
3. Temperature
4. NPK levels
5. pH for aquatic systems

This is not the complete list. Assuming all of the above are optimum then the supply of energy is the rate limiting step. Any no-optimisation of the above (unavoidable) will reduce the yield. Selectively breeding and tinkering with the algae species is not going to have any effect on the theoretical yield, though it might (a big might) potential allow some leeway in the parameters above. Playing with the antenna is not likely to achieve much in my opinion. Reducing the antenna size will have an adverse impact in low light conditions, particularly shading which results in aquatic systems. There might be some scope in the chlorophyll absorption range, but I doubt it.

Isgota has provided an example form Algenol. Algenol have made many claims and have been plying their process for years. I doubt if it can be made to work commercially. But let us examine their claim, provided by the Isgota post, of an ethanol yield of 8000 gallons per acre. As ever the devil is in the detail and misleading units are always used to mask the truth. For simplicity I will use the following conversions:

1 acre as 4000 square metres.

Average PAR lower US 100 watts/square metre (8760 hrs/year) = (8760 x 100 x 3600) = 3.153 GJ per square metre

(For simplicity- I have not calculated photon density or number of photons which is more correct)

PAR source: http://www.atmos.umd.edu/~srb/par/Figure01.htm

8000 UG galls ethanol per acre = 2 US galls per square metre


2 US galls ethanol = 6 kg ethanol

1 kg ethanol = 30 MJ HHV

Energy of Ethanol produced = 180 MJ (6 x 30)

Efficiency on ethanol yield = 180/3153 x 100 = 5.7%

Now for a C3 plant, which algae is, to produce a 5.7 % yield of ethanol (+ other products which are required by the algae cell) this would be exceptional
(some might say impossible, which is where I sit).

The believer types on this board would republish the Algenol claims as fact, invest their life savings in Algenol shares, sit back and wait for the world is about to change to biofuels. The slightly sharper types might scratch their heads and start calculating and doubting. The even sharper types will start shouting SCAM and words like it exceeds the the theoretical limit, or why is it not commercially viable then?

The believer types will then come back with evidence from some "Bionews" publication (take your pick) of the impending explosive growth of such a process and shout that the sceptics are wrong, because it is in "Bionews", that they do not know what they are talking about, that they are lackeys of the fossil fuel industry, and even worse, they might even be the sinner of sins, a self confessed petroleum chemist. If you are really lucky you might even be maligned as an engineer with 10 minutes of experience working for a consultant. The believers are even more vociferous if the SCAM artist has won a biofuel award and his company is haemorraging money like there was no tomorrow.

Yes, that is the reality when you objectively reply to some of the believers - just read the posts.

So going back to the start of the post. In my opinion the failure of biofuels to be commercially viable, now and most likely in the future, is down to thermodynamic limitations. None has yet shown a significant net energy gain and an EROEI than would allow them to be competitive against existing fossil fuels, now and in the future. The cost of these biofuel products is linked to the cost of existing fossil energy and will not decouple any time soon. None has shown any evidence that in the absence of fossil energy inputs that they can operate in a stand alone cycle, either singly or in mixed mode. Trying to replicate what nature has done of millions of years processing fossil fuels is simply not possible. That means we will be reliant on fossil fuels until they are depleted and then who knows. Some biofuels might be possible for limited applications but they are not going to power the world as it is today for the masses. Get used to the idea.
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Re: THE Algae Thread pt 2 (merged)

Unread postby vtsnowedin » Tue 21 Jul 2015, 06:11:36

pstarr wrote:No. Algae fuel would be made with petroleum, so the cost/price is indexed with petroleum.

Not necessarily. In a post peak world you would run your algae ponds on solar PV panels as it would sync up with when you need to run pumps when photosynthesis was actually happening. or wind ,or Hydro power or wood fired combined cycle generation stripping off the CO2 from the wood fires.
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