Exploring Microalgae as Solutions to Global Fuel Issues

[Ivan Seeking]

Clever idea, but doesn't this imply the reactor has to be sealed and capable of withstanding some pressure, and if that is the case what is the economic advantage of placing the farm in the ocean (vs land or lake) and having to deal with marine operations?

Many designs for bioreactors are basicaly just big plastic bags filled with water. They already have a fair degree of mechanical strength as required by the weight of the water. It would be easy to modify these for total submersion. An air gap above the algae water would normally make the reactor slightly buoyant.

As stated earlier, there are several advantages. The biggest consideration is the cost of land [and property taxes], which is siginficant to the cost of production, thus the required yields, thus the required CO2 supply. We can live with less CO2 if we don't require the maximum possible yields. Also, no land preparation is required. While the cost of a marine bioreactor may be higher than one for land [I don't know that it would be!], land preparation can be a costly proposition for a new site. Next, semi-submersion in marine environments means that we naturally have very stable temps. This is highly siginficant as closed systems are also greenhouses by nature. It takes energy to keep them cool. Also, extreme winter conditions eliminate the chance of winter crops. In fact, this is what killed the bloom used in the Aquatic Species Program! If it is even possible, temperature regulation is critical and it can be energy costly. Coastal areas generally have moderate temps. Additionally, we have a ready supply of water with no energy-expensive deep pumping required. There are other practical advantages. For example, we have no drainage problems, land use laws, or concerns about flooding. Finally, the energy cost of mixing [water circulation], which can be significant, might be reduced by cleverly tapping the energy in the wave action of the ocean.

If one can significantly reduce the cost of start-up and operations - financially and in terms of energy - one can live with lower yields. This could make algae-fuels cost-competitive sooner than they would be otherwise.

Note also that diesel generators needed for processing the algae would supply about 40% of the CO2 needed for growth. This is added to the ambient CO2. There is no reason why any closed system should be limited to the ambient CO2 supply. The fact that processing is energy costly also means that we have a signficant CO2 supply to boost the growth rate of the algae. As discussed earlier, the diesel engines might even be easily modified to "fix" a good percentage of the required nitrogen.

 

[Ivan Seeking]

Late edits above:

We already know that we don't want algae competing with people, live stock, or food crops, for fresh water. When one considers the annual water demand were algae fuels to replace the petroleum supply, it becomes evident that we want to drive this towards the salt-water based algae strains. This is consistent with the idea of marine-based farms.

Haha, maybe we could convert the platforms from spent oil wells into bases for algae farms!

 

[mheslep]

Late edits above:

We already know that we don't want algae competing with people or food crops, for fresh water. When one considers the annual water demand were algae fuels to replace the petroleum supply, it becomes evident that we want to drive this towards the salt-water based algae strains. This is consistent with the idea of marine-based farms.

Yes that is surely a strong point in favor of a marine based-farm. For every mole of the 378 million gallons of liquid hydrocarbon used per day in the US, some 2-3-4-5 moles (depending on the hydrocarbon) of water would be required to replace the petrol with biofuel. However, the difficulty in keeping wild strains and toxins out of that ~billion gallons per day of seawater seems intractable.

 

[Ivan Seeking]

Yes that is surely a strong point in favor of a marine based-farm. For every mole of the 378 million gallons of liquid hydrocarbon used per day in the US, some 2-3-4-5 moles (depending on the hydrocarbon) of water would be required to replace the petrol with biofuel. However, the difficulty in keeping wild strains and toxins out of that ~billion gallons per day of seawater seems intractable.

I don't see why contamination would be any more problematic that it would be for a land-based system. It is a problem but true in either case. Clearly all water used in the system will require proper treatment. But from there it is a closed system.

Again, incidently, ~40% of our water is purified and returned to the system by the diesel engines.

 

[Ivan Seeking]

Biodiesel has over 20 hydrogen atoms per molecule - a 10 times or better multiplier for water demand, per mole of fuel.
http://www.pwista.com/Organic/Preparation%20of%20Biodiesel.pdf

Late edit: In fact, it should be more like a 15x multiplier because some hydrogens are lost to the glycerine precipitate formed during the transesterification [biodiesel] reaction. The critical fatty acids are mostly in the mid thirties, in terms of the hydrogen count per molecule.

 

[Ivan Seeking]

Using some typical numbers: If we assume that we purchase land for $10K per acre, [assuming that we have 10% cash to put down] we might expect to pay 1%, or $100 per month per acre, for a 30 year fixed loan. Property taxes could easily be another $100 per acre per year, say $10 per month. Reasonably, we might also assume that land preparation doubles our start-up costs, so we assume $200 per acre-month for the startup cost of the site. With taxes this suggests an expense of about $210 per month per acre, for thirty years.

Assuming the highly optimistic case of 7000 gallons of fuel per acre-year gross, and 60% processing efficiency, we expect 4200 net gallons of fuel per acre-year, or 350 gallons per acre-month. Assuming an effective wholesale market price [after testing and taxes] of $1.00 per gallon, the cost of land and taxes alone require 60% of our gross income. Assuming a more moderate 5k gallons per acre-year, land and taxes require over 80% of our gross income.

Obviously we would look for better options such as land leases, but the numbers show how significant the cost of land and taxes can be as a percentage of the gross revenues generated. Note that we still have to pay to operate the farm.

 

[mheslep]

I don't see why contamination would be any more problematic that it would be for a land-based system. It is a problem but true in either case. Clearly all water used in the system will require proper treatment. But from there it is a closed system. ...

I assumed a land system would have access to fairly contaminate free water supplies? Perhaps municipal water would be available, if not then rain collection, well water, or even clean rivers. I have little or no idea what ppm of wild algae is found in those water sources. If it has to be cleaned - that's a colossal job at this scale.

 

[mheslep]

Using some typical numbers: If we assume that we purchase land for $10K per acre, [assuming that we have 10% cash to put down] we might expect to pay 1%, or $100 per month per acre, for a 30 year fixed loan. Property taxes could easily be another $100 per acre per year, say $10 per month. Reasonably, we might also assume that land preparation doubles our start-up costs, so we assume $200 per acre-month for the startup cost of the site. With taxes this suggests an expense of about $210 per month per acre, for thirty years...

Interestingly there's a detailed business analysis report authored by a US national lab on the failure of a California solar farm for just these kinds of reasons - they failed to identify property taxes, etc. until too late.

 

[Ivan Seeking]

I assumed a land system would have access to fairly contaminate free water supplies? Perhaps municipal water would be available, if not then rain collection, well water, or even clean rivers. I have little or no idea what ppm of wild algae is found in those water sources. If it has to be cleaned - that's a colossal job at this scale.

A significant energy cost is paying to run the pumps that push the water through the filters. No way to avoid that one. But it isn't practical to purify the water to laboratory standards, so it becomes a race to create a harvestable bloom before the bad things take over. This is why, in my own plans, it was critical to innoculate a new batch using as much pure growth as possible.

Presumably, chlorination would also play a role in treating raw water, but I have never worked with salt-water systems, so I don't know what the options may be.

As for municipal water sources, they have the same energy and financial costs as would a large farm. And, with possibly a few rare exceptions, there is no natural water source that could be considered "clean".

 

[mheslep]

As mentioned above. This is on-topic IMO - solar shares all of the same land costs / taxes as algae (would).
Barriers to Commercialization of Large Scale Solar Electricity: Lessons Learned from the LUZ Experience
http://www.nrel.gov/csp/troughnet/pdfs/sand91_7014.pdf

See in particular the Barrier Sections
V: Energy Pricing Policy
VI: Artificial Size Limitations Under PURPA
VII: Annual expiration of the energy tax credits and AMT limitations.
VIII: Property taxes
IX: Other taxes
and so on

 

[Ivan Seeking]

An interesting perspective that sort of popped off the page at some point:

Not surprisingly, while trying to write a business and technical plan for all of this, it soon became evident that the cost-siginficance of any particular component of the farm, is related, in a sense, to its dimensionality. The cost of anything having a specific location, such as a generator, tends to be relatively small as compared to the total cost of the farm. When we consider things measured linearly, such as pipe, the cost becomes significant. Anything measured in terms of area, such as land, or bioreactor surface, becomes cost-critical. The reason for this is the scale of the project. It is difficult to remember just how much area we are talking about.

I found there was an intuitive disconnect for me when we start talking about thousands of gallons per acre-year. In fact this is a very low energy density over area. In the end we are only talking about 100 watts or so of captured, recoverable power, per sq meter, and only during the day. We get nothing by night. How much does it cost to run a lightbulb? There is your energy and operating budget, including profits, per square meter. That is difficult to keep in perspective. It is easy to imagine that any additional cost for marine reactors, as opposed to land-based reactors, may be insignficant compared to the cost of land, and land preparation, which are both heavy-hitting area problems.

The energy cost of mixing keeps coming to mind as well. Mixing, or stirring, becomes problematic because we have to keep the water moving over the entire surface of the reactor bed [an area problem]. If we have one foot of water in our reactor, this means that we have to stir 326,000 gallons of water per acre, or about 80 gallons per lightbulb, over thousands, or hundreds of thousands of acres, per farm. Likewise, if we can steal wave energy over the entire surface of the reactor, while the energy density of the wave action may be small, we are talking about a very large area, so the energy savings are signficant.

 

[Ivan Seeking]

In my own efforts, what ultimately drove the choice for the depth of the water in the reactor bed, was the need to avoid wild fluctuations in the temperature of the algae water. The mass of water required per square meter - thus the depth of the water - was calculated according to the anticpated solar and ambient energy input to the system during the day, the energy [heat] lost at night, heat energy lost to and gained from the land, and the maximum acceptable water-temperature swings. This in turn determines not only the energy required for mixing per unit [surface] area, but also the time that any particular algae cell spends at the surface of the water; thus the efficiency of the reactor. Presumably, there are ideal periods of time spent on the surface - the only photosynthetically active period for the cell - and then below the surface, for any given algae cell, and perhaps for each strain of algae. If temperature control is not an issue [due to contact cooling with the ocean water], then it would seem that the reactor design can be driven by the ideal circulation rates and activity periods, for any given strain of algae.

Note that the qualifiers "presumably", "it would seem", and the like are meant to make clear that this is my impression of the problem based on a long and dedicated review of the literature - that this is representitive of the mainstream discussions and literature.

 

[baywax]

Ivan, is there any chance that algae will grow in the dead zones around sewage treatment plant outflows...? These are usually in the ocean and just off shore. the oceans temp never varies much more than 2 degrees over the year.

 

[Ivan Seeking]

Ivan, is there any chance that algae will grow in the dead zones around sewage treatment plant outflows...? These are usually in the ocean and just off shore. the oceans temp never varies much more than 2 degrees over the year.

In all likelihood, it is best to treat the runoff or discharge before it reaches the open oceans. In fact dead zones are often created by spontaneous algae blooms, often due to the presence of nitrogen, that choke off the oxygen supply for everything else. So, interestingly, the choice can be, a controlled bloom now, or an uncontrolled bloom later. It reminds me a bit of Judo where you use your opponent's momentum against them.

You may remember what happened along the Chinese coast, just before the Olympics. I don't know if the cause of that bloom was identified, but it typically comes down to high temperatures, and/or the presence of relatively high levels of nitrogen due to, sewage, agricultural runoff, or industrial waste products. In any case, nitrogen is critical to algae growth.

[PLAIN]http://www.pe.com/imagesdaily/2008/07-01/china_olympics_algae_400.jpg

BBC report
http://news.bbc.co.uk/2/hi/7485405.stm

In fact, algae is certainly already a part of the cleanup process in the case of constructed wetlands.
http://www.toolbase.org/Technology-Inventory/Sitework/constructed-wetlands
http://www.unep.or.jp/ietc/publications/freshwater/watershed_manual/03_management-10.pdf

 

[Ivan Seeking]

...or did you mean that we tap the end of the discharge pipe for a controlled farm? Flying by the seat of my pants here, that sounds like a tempting idea. Open systems, such as wild blooms in the ocean, can be a real problem, but if the discharge was incorporated into a marine farm having a closed system, in broad strokes here, that could work.

As a best case, I would think, treatment on the front end would likely need to be significantly modifed, but waste products tend to be great sources of nitrogen and phosphorous - which is also critical to growth. The big problem that I do see here is that of toxins, industrial chemicals, and even measurable levels of drugs, like morphine! As it stands now, raw sewage is a real witch's brew. I don't know what the potential for serious drawbacks may be if algae intended for fuel is used to treat an uncontrolled discharge. For that reason, I would expect it likely that front-end treatment would be critical, with mainly the nitrogen and phosphorous left for the algae, at the discharge pipe.

 

[baywax]

...or did you mean that we tap the end of the discharge pipe for a controlled farm? Flying by the seat of my pants here, that sounds like a tempting idea. Open systems, such as wild blooms in the ocean, can be a real problem, but if the discharge was incorporated into a marine farm having a closed system, in broad strokes here, that could work.

As a best case, I would think, treatment on the front end would likely need to be significantly modifed, but waste products tend to be great sources of nitrogen and phosphorous - which is also critical to growth. The big problem that I do see here is that of toxins, industrial chemicals, and even measurable levels of drugs, like morphine! As it stands now, raw sewage is a real witch's brew. I don't know what the potential for serious drawbacks may be if algae intended for fuel is used to treat an uncontrolled discharge. For that reason, I would expect it likely that front-end treatment would be critical, with mainly the nitrogen and phosphorous left for the algae, at the discharge pipe.

That's sort of what I was getting at. Though I hadn't thought of using the algae as part of the treatment... then using the algae as a source of fuel. Win win! I imagine controlling a bloom in the ocean would be difficult because of the changing conditions... but diverting the wastewater to a controlled environment makes sense. Thanks Ivan...!

 

[mheslep]

In my own efforts, what ultimately drove the choice for the depth of the water in the reactor bed, was the need to avoid wild fluctuations in the temperature of the algae water.[...]

If you use water circulation that greatly reduces the temperature gradients, no?

 

[Ivan Seeking]

If you use water circulation that greatly reduces the temperature gradients, no?

Yes, however we still have the problem of the total energy input [about 700-800 watts solar per sq meter that goes to heat, on a good day], and the resulting temperature rise.

 

[Ivan Seeking]

Given my location, it was also necessary to assume a worst case of, nighttime lows of 20 degrees F, and many days - November through January - with as little as ~ 400 watts of heating per sq meter during the daylight hours. From the start it was clear that this was pushing the limits of what was manageable. Clearly it would be necessary to vary the strain as a function of the season. Strains that might work well here in the summer certainly couldn't be managed in the winter. There are low-temperature strains that it seemed might survive the winter months given the proper reactor design. One advantage that we have here is that our coldest days are usually bright and sunny. In theory, that gave me a bit of wiggle room. Also, by maximizing the contact area with the Earth [by shaping and sizing the ditches], relative to the reactor's exposed surface area, it was intended that enough heat from the Earth could be captured in order to survive the coldest nights.

 

[Ivan Seeking]

The best case that I could see using processing and biotechnologies now, or, hopefully, soon to be available, and assuming that the price of fuel stays a little above $3.00 per gallon retail, was that a land-based farm might be profitable beginning at about 50k-100K acres. One of the big drivers for this was the efficiency of the power plant - for the power required to run the farm and processing equipment. At large scale, we can use systems having the highest efficiency - likely, turbine engines with heat recovery systems. Though, diesels modified for very high compression, for the nitrogen fix, are a promising avenue of thought. The very high compression makes them more efficient. Plus, we get the free nitrogen. I don't know if this same approach could be used on a turbine engine; that is, that we could get the same benefit of high NOX emissions.

100,000 acres is about 156 sq miles, or 12.5 miles on a side.

 

[Ivan Seeking]

Another landmark achievement related to algae research: Bacterial Cell with a Chemically Synthesized Genome
:https://www.physicsforums.com/showthread.php?t=404603

The ability to design algae or bacteria for fuel production, has long been touted as a pinnacle achievement of future research, so this is highly significant to the viability of algae for fuel. Since microalgae and bacteria are simple life forms, one might hope for specific progress in this area - fuel production - as soon as any other. Not to mention that there is approximately a one-trillion dollar per year market incentive to replace fossil fuels, with sustainable, domestically produced, clean fuels, just in the US.

This could eventually open the door to a viable supply of organically-produced hydrogen. If we have a viable source of hydrogen, the hydrogen economy will have its currency. Note that microalgae may be a potentially good source of hydrogen, as well as ethanol, biodiesel, and perhaps even fuels similar to gasoline.

 

[Ivan Seeking]

Speaking of incentive
https://www.physicsforums.com/showthread.php?p=2729867#post2729867

 

[mheslep]

Speaking of incentive
https://www.physicsforums.com/showthread.php?p=2729867#post2729867

In the case of an offshore oil algae farm (vs ethanol) https://www.physicsforums.com/showpost.php?p=2692472&postcount=453" producing, say 1 million bbls per year, what's implicit in the process that would stop the same kind of disaster from happening in the case of an accident during a storm?

 

[Ivan Seeking]

I will quote from the other thread and redirect any additional discussion here

Oil from algae is just vegetable oil. It is non-toxic. You can drink it. And it degrades readily. Also, without a significant source of nitrogen and the proper temps, the algae won't survive in open water - that is, it wouldn't exist as a giant plume that kills everything else. If you have these conditions, you would already have an algae bloom, in most cases.

You would certainly have a lot of fish food!

Also, you wouldn't have millions and millions of gallons of oil leaking endlessly. You could only spill the oil that has been processed. The rest is still trapped in the algae.

https://www.physicsforums.com/newreply.php?do=newreply&p=2730137

 

[Ivan Seeking]

Note that there are some strains of algae that release neurotoxins. Obviously these strains are not considered viable candidates for fuel production. They do present a real threat, however, to anyone working with algae. It is important to know what you're dealing with. Toxic, invasive strains, could be an issue if not checked. Again, a batch process helps to minimize this concern.

 

[mheslep]

Ok moved here ...

Oil from algae is just vegetable oil. It is non-toxic. You can drink it.

Sure, and the http://web.grcc.edu/Pr/msds/automechanics/MotorOil.pdf" lists it as 'relatively non-toxic'. A million barrels of vegetable oil dumped into the ocean could not be called harmless in my view. Covering the plumage of birds with any kind of heavy oil is going to kill them just as dead.

I might be wrong, but I believe the lightweight aromatics (e.g. benzene) are the most toxic compounds contained in the mixture commonly called petroleum. We know they evaporate fairly quickly. So, once the aromatics are gone in a spill like this, and reports suggest they are, I'm curious about the difference in toxicity, or more precisely the harm, between the petroleum products remaining after evaporation, and the oil produced by a biodeisel grade algae.

Also, without a significant source of nitrogen and the proper temps, the algae won't survive in open water - that is, it wouldn't exist as a giant plume that kills everything else. If you have these conditions, you would already have an algae bloom, in most cases.

The cells may die but the hydrocarbon compound remains. Then there are the modified strains (from Exxon and Craig Venter) that secrete the oil outside of the cell to make oil collection more economic. In that case, the fate of the algae cells themselves is irrelevant to an accident.

 

[Ivan Seeking]

Ok moved here ...

Sure, and the http://web.grcc.edu/Pr/msds/automechanics/MotorOil.pdf" lists it as 'relatively non-toxic'. A million barrels of vegetable oil dumped into the ocean could not be called harmless in my view. Covering the plumage of birds with any kind of heavy oil is going to kill them just as dead.

This would be a simple matter of regulating the maximum quantity of oil that can be stored. That is quite a different problem from what we face in the gulf. And there is no need for the Exxon Valdez when the oil source is 80 miles offshore.

Would you drink motor oil? Don't try to spin this as if there is no difference between crude oil, and food. That is a ludicrous position to assume.

I might be wrong, but I believe the lightweight aromatics (e.g. benzene) are the most toxic The cells may die but the hydrocarbon compound remains. Then there are the modified strains (from Exxon and Craig Venter) that secrete the oil outside of the cell to make oil collection more economic. In that case, the fate of the algae cells themselves is irrelevant to an accident.

The algae plume cannot exist without the proper nutrients. The majority of the stuff would die and sink to the bottom of the ocean; just as happens already in the normal CO2 sequestration process naturally provided by algae.

The potential problem of releasing bioengineered strains of algae into the wild, is another concern. But I would prefer that discussion be redirected to a dedicated thread, as that is a huge topic generally for all of biology. One immediate thought that comes to mind is that, if algae are famous for doing anything, it is mutating. Given the countless strains of algae found around the world. And considering the existing rate of mutation for natural algae, it seems that we would be hard-pressed, by many orders of magnitude, to pose a greater threat than already exists in nature, to produce a dangerous strain of algae. We could also design strains to be safe. Nature has no such motivation. In fact, it is my understanding that algae essentially have wars when strains are competing the wild. In effect, each strain mutates until one produces something toxic to the other.

 

[dgtech]

That is about one Iraq war every year in returns.

Since when is invading a country with crippled military infrastructure considered a war, or even a unit of measurement for that matter?

Algae is great, most of the treehuggers out there don't realize the majority of oxygen is being released by algae and not trees (I am not justifying deforestation, I strongly oppose it). Not to mention it is capable of producing bio mass as much as 30x times faster than any plant, making ethanol production from corn or soy look moronic at best.

The byproduct of oil production from algae is a good food additive for farm animals.

There are also many more potential benefits, what is critical is the actual execution, as we, humans have a history of misusing everything good we come in contact with.

Genetic engineering should be outlawed, its potential benefits far being far exceeded by its potential harm. No need to play gods and trying to better nature, all we need is to stop destroying it and if we have the resource - helping out a bit, but without playing Dr. Frankenstein

 

[mheslep]

This would be a simple matter of regulating the maximum quantity of oil that can be stored.

If one wants to seriously explore using offshore algae farms at a scale capable of replacing the global petroleum industry, I see nothing 'simple' about avoiding temporary storage of, say, a 1. 7 million bbl/day rate of production (Gulf of Mexico production). In fact I suggest it is a practical impossibility to avoid having at least a significant fraction of a day's oil production on the water at a given moment.

That is quite a different problem from what we face in the gulf. And there is no need for the Exxon Valdez when the oil source is 80 miles offshore.

Eh? The Valdez (ship) collided with the shore (essentially), hence the concentrated damage at Valdez (port/town)

Would you drink motor oil? Don't try to spin this as if there is no difference between crude oil, and food. That is a ludicrous position to assume.

I'm not. I'm attempting to explore the technical difference in degrees of harm which means going past hand waiving about what one can drink in small qty. Petroleum oil spills are visibly harmful. I now am asking why a hydrocarbon like CnH2(n+1-g) (naphthene from petroleum) is credited with ruining the Gulf but the same amount of hydrocarbon C3H5O6C(CnH(2n+x))3 (Canola) is somehow harmless fish food?

Edit: Another point as to why quantity must be important: there's always some background natural seepage of oil, several million bbl per year worldwide, which the oceans seem to have well tolerated long before oil rigs appeared.

The algae plume cannot exist without the proper nutrients.

We've already been there. The disposal of the oil itself, once created, does not depend on the health of the algae. The difference from offshore petroleum production would be two fold, I believe: one, the continuing production of algae oil could be stopped almost immediately, but two, a realistic algae farm would necessarily have an enormous amount of oil present on the surface at anyone time which all could be theoretically released, worst case, into the ocean.

 

[mheslep]

On this subject, this study is interesting to me for two reasons: 1) the background material gives some chemical description of what components of a petroleum spill actually end up on the beaches, and tangentially 2) it turns out biodiesel has been shown effective in breaking up the 'waxy' components. The study also notes that biodiesel is readily biodegradable, but I'm not clear that this means its parent triglyceride are also equally degradable before transesterification.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VH4-40D61CC-9&_user=3938616&_coverDate=10%2F01%2F1999&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1347997386&_rerunOrigin=google&_acct=C000061828&_version=1&_urlVersion=0&_userid=3938616&md5=6c629c1336083f95c7e5b3da5b68c0ba#bbib5"
Spill Science & Technology Bulletin
Volume 5, Issues 5-6, 1 October 1999, Pages 353-355

Abstract

Experiments using biodiesel derived from vegetable oils have demonstrated the considerable potential for removing crude oil from contaminated beaches. During laboratory studies in small boxes, contaminated sand treated with biodiesel also demonstrated the rapid biodegradation of the crude oil. Water soluble components were washed through the sand columns and these components subsequently precipitated with cold storage. This solid fraction was not soluble in organic solvents but could be re-dissolved in dilute acid. The sediments after four weeks were black in colour due to the precipitation of metal sulphides although no H2S was generated because the pH of the seawater kept the sulphides in solution. Further work is investigating which components of the oil were degraded and what products were formed

Introduction

Previous work has demonstrated the usefulness of biodiesel, the methyl derivatives of vegetable oils, in the removal of crude oil from intertidal sediments (Miller & Mudge, 1997; Mudge and co-workers, unpublished reports). Biodiesel acts as a non-volatile organic solvent and dissolves the crude oil, including weathered oil. In most cases of crude oil contamination on beaches, the oil has been at sea and most of the volatile compounds (e.g., BTEX, short chain aliphatics) have evaporated off and only the less volatile components (e.g., PAHs, long chain aliphatics) reach the shore. Biodiesel is able to dissolve these waxy components and make them more mobile in the environment. Experiments are in progress to determine the best application methods and efficiencies of removal. As part of this work, a biological side-effect has been observed which makes biodiesel even more useful than originally thought.

Biodiesel has been used as a diesel fuel substitute or additive for many years (see Louwrier, 1998 for a review) and previous work has demonstrated the rapid degradability of biodiesel in the environment; 95% after 28 days in an aqueous environment.[*] More recent work by the same group (Zhang, X., Peterson, C., Reece, D., Haws, R. and Moller, G., 1998. Biodegradability of biodiesel in the aquatic environment. Trans. ASAE 41, pp. 1423–1430. View Record in Scopus | Cited By in Scopus (34)Zhang et al., 1998) has examined the degradability using EPA methods and concluded that biodiesel is “readily biodegradable”. [...]

[*] So what is the 95% breakdown time of the crude oil products?

 

[mheslep]

EPA to the rescue with the answer to my question and then some. Apparently the answer is quite complex.

In 1994 a gaggle of agricultural associations attempted have the EPA change the Clear Water Act rules and label them (oils and fats vendors) more or less harmless, as different from the 'bad' and 'toxic' petroleum products industry. The 'petitioners' were
the American Soybean Association, the Corn Refiners Association, the National Corn Growers Association, the Institute of Shortening & Edible Oils, the National Cotton Council, the National Cottonseed Products Association, and the National Oilseed Processors Association.

http://www.epa.gov/EPA-WATER/1999/April/Day-08/w8275.htm

a. Petitioners' request. [...] Based, in part, on these studies, the Petitioners asked us to create a regulatory regime for response planning for ``non-toxic,'' non-petroleum oils separate from the framework established for petroleum oils and ``toxic'' non-petroleum oils. They suggested specific language[...] For facilities that handle, store, or transport animal fats and vegetable oils, their suggested revisions would: modify the definition of animal fats and vegetable oil (set out in Appendix E, Section 1.2 of the FRP rule); allow mechanical dispersal and ``no action'' options to be considered in lieu of the oil containment and recovery devices otherwise specified for response to a worst case discharge; require the use of containment booms only for the protection of fish and wildlife and sensitive environments; and increase the required on-scene arrival time for response resources at a spill from 12 hours (including travel time) to 24 hours plus travel time for medium discharges and worst case Tier 1 response resources.

and the EPA response:

c. Denial of petition. On October 20, 1997, EPA denied the petition to amend the FRP rule. We found that the petition did not substantiate claims that animal fats and vegetable oils differ from petroleum oils in properties and effects and did not support a further differentiation between these groups of oils under the FRP rule. Instead, we found that a worst case discharge or substantial threat of discharge of animal fats and/or vegetable oils to navigable waters, adjoining shorelines, or the exclusive economic zone could reasonably be expected to cause substantial harm to the environment, including wildlife that may be killed by the discharge. We pointed out that the FRP rule already provides for different response planning requirements for petroleum and non-petroleum oils, including animal fats and vegetable oils.
We also disagreed with Petitioners' claim that animal fats and vegetable oils are non-toxic when spilled into the environment and should be placed in a separate category from other ``toxic'' non-petroleum oils. Information and data we reviewed from other sources indicate that some animal fats and vegetable oils, their components, and degradation products are toxic. Furthermore, we emphasized that toxicity is only one way that oil spills cause environmental damage. Most immediate environmental effects are physical effects, such as coating animals and plants with oil, suffocating aquatic organisms from oxygen depletion, and destroying food supply and habitats. We noted that toxicity is not one of the criteria in determining which on-shore facilities are high-risk and must prepare response plans. Rather, the criteria for determining high-risk facilities are certain facility and locational characteristics, because we expect that discharges of oil from facilities with these characteristics may cause substantial harm to the environment

Further down in bullet form:
Like petroleum oils, animal fats and vegetable oils and their
constituents can cause toxic effects that are summarized below. They
can:

• Cause devastating physical effects, such as coating animals and plants with oil and suffocating them by oxygen depletion;
• Be toxic and form toxic products;
• Destroy future and existing food supply, breeding animals, and habitat;
• Produce rancid odors;
• Foul shorelines, clog water treatment plants, and catch fire when ignition sources are present; and
• Form products that linger in the environment for many years.

The EPA's exploration of the technical background is very interesting.

 

[mheslep]

Technical section:

While the physical and chemical properties of vegetable
oils and animal fats are highly variable, most fall within a range that
is similar to the physical parameters for petroleum oils. Common
properties--such as solubility, specific gravity, and viscosity--are
responsible for the similar environmental effects of petroleum oils,
vegetable oils, and animal fats.
In one respect, however, many petroleum oils differ from most
vegetable oils and animal fats. Unlike most vegetable oils and animal
fats, many petroleum oils have a high vapor pressure. The high vapor
pressure of petroleum oils can lead to significant evaporation from
spills. It may also produce exposure of nearby populations through the
air pathway.

We describe some important properties of oil below.

Solubility. Solubility refers to the ability of a chemical to dissolve in water or solvents. Like petroleum oils, vegetable oils and animal fats have limited water solubility and high solubility in organic solvents.

Specific Gravity. Specific gravity is the ratio of the density of a material to the density of fresh water. Specific gravity determines whether an oil floats on the surface of a water body or sinks below the surface and how long oil droplets reside in the water. It can also give a general indication of other properties of the oil. For example, oils
with a low specific gravity tend to be rich in volatile components and are highly fluid International Tanker Owners Pollution Federation, 1987). The specific gravity of vegetable oils and animal fats whose properties we examined is within the range of specific gravity values for petroleum oils.

Viscosity. Viscosity refers to the resistance to flow. It controls the rate at which oil spreads on water and how deeply it penetrates the shore. Viscosity also determines how much energy organisms need to overcome resistance to their movement. At similar temperatures, the dynamic viscosity (shear stress/rate of shear) and kinematic viscosity (dynamic viscosity/density) of vegetable oils and animal fats are
somewhat greater than those for light petroleum oils but less than those for heavy petroleum oils. The viscosity of canola oil represents a medium weight oil and is comparable to that of a lightly weathered Prudhoe Bay crude oil after it has evaporated by 10 percent (Allen and Nelson, 1983).

Vapor Pressure. Vapor pressure is the pressure that a solid or liquid exerts in equilibrium with its own vapor depending on temperature. It controls the evaporation rate of an oil spill and air concentrations. The higher the vapor pressure of an oil, the faster it evaporates. Vapor pressure varies over a wide range for petroleum oils, from moderately volatile diesel-like products to slightly volatile heavy crude oils and residual products. The vapor pressure of animal fats and vegetable oils is generally much lower than that of many petroleum oils. Evaporation is significant for many petroleum oil spills, some of which completely evaporate in one to two days, but it is rarely an important factor in spills of vegetable oils and animal fats. In some vegetable oils, however, there is a small volatile fraction that can evaporate. Thermal decomposition can also cause the formation of many volatile degradation products.

Surface Tension. The spreading of oil relates to surface tension (interfacial tension) in a complex manner. When the sum of the oil-water and oil-air interfacial tensions is less than the water-air interfacial tension, spreading is promoted. At 25 deg.C, the oil-water interfacial tension for canola oil is far less than that of Prudhoe Bay crude oil, suggesting that canola oil could spread more (Allen and Nelson, 1983). Surface tension measurements in the laboratory, however, are not necessarily predictive of the behavior of oil that is being transformed by many processes in the environment.

Emulsions. Emulsions are fine droplets of liquid dispersed in a second, immiscible liquid. When oil and water mix vigorously, they form a dispersion of water droplets in oil and oil droplets in water (Hui, 1996c). When mixing stops, the phases separate. Small water drops fall toward the interface between the phases, and the oil drops rise. The emulsion breaks. When an emulsifier is present, one phase becomes continuous, while the other remains dispersed. The continuous phase is usually the one in which the emulsifier is soluble.
The tendency of petroleum and non-petroleum oils to form emulsions of water-in-oil or oil-in-water depends on the unique chemical composition of the oil as well as temperature, the presence of stabilizing compounds, and other factors. When an emulsion is formed in the environment, the oil changes appearance and its viscosity can increase by many orders of magnitude. Removal of the oil becomes harder because of the increased difficulty in pumping viscous fluids with up to fivefold increases in volume.
[...]

Adhesions. Although the ability to form adhesions is difficult to measure and predict, adhesions influence the ease with which spilled oil can be physically removed from surfaces. When water is colder than the oil pour point, oils become viscous and tar-like or form semi-solid, spherical particles that are difficult to recover. Weathering and evaporation are slowed, and oils may become entrapped or encapsulated in ice and later may float on the surface when ice breaks up. In ice adhesion tests, canola oil and Prudhoe Bay crude oil had the same tendency to coat the surface of sea ice drawn up through an oil/water interface (Allen and Nelson, 1983). Neither oil adhered to submerged sea ice even after surface coating. This study suggests that some vegetable oils and petroleum oils have a similar ability to form adhesions under certain environmental conditions.

 

[Ivan Seeking]

It looks like Obama finally read my letter.

"We're making new investments in the development of gasoline and diesel and jet fuel that's actually made from a plant-like substance. Algae. You've got a bunch of algae out here, right?" President Obama said at a campaign event in Coral Gables, Florida.

"If we can make energy out of that, we will be doing alright," Obama said.

http://www.realclearpolitics.com/video/2012/02/23/147_obama_if_we_could_make_energy_out_of_algae_well_be_alright.html

 

[OmCheeto]

It looks like Obama finally read my letter.


http://www.realclearpolitics.com/video/2012/02/23/147_obama_if_we_could_make_energy_out_of_algae_well_be_alright.html

One of the things I've learned from my recent classes, and from experience over the last 30 years, is that if you put out an incredibly great idea, and then give leadership a long enough time lag, they will eventually think it was their idea to begin with, and it will get done.

There are innovators, there are entrepreneurs, and there are leaders.

shhhhhhh!

 

[Ivan Seeking]

I don't know if Chu has given up on his cellulosic ethanol but I'm glad to hear Obama talking about algae. Chu was definitely driving things the other direction - towards ethanol - as that was his focus before becoming the Energy Secretary.