This is going to be built in the spring.

 

A PBR (Photo-Bio-Reactor, not Pabst Blue Ribbon) will be constantly grow Botryococcus braunii, Some will be kept in a development tank but the majority will be released into a raceway pond system.

The pond system will be about 6 feet deep, and not all that turbulent. It will be open at first, but with walkways and attachment points for a variety of coverings. Algae will be scooped off the surface, lightly strained, exposed to a hexane solvent to extract a large portion of the oil. The oil/hexane and algae/hexane lines will split at this point. Each line will separately undergo vacuum recovery of the hexane. The Bb will then be returned to the pond.

 This may look odd. Now I will explain why each step has been done.

The PBR is to have a reserve of Bb, in case of infection by an undesireable organism. By constantly adding the Bb, we keep its population high enough so as not to give other species an opportunity to get a foothold. If an invasion happens anyhow, we disenfect the pond and seed again with Bb from the development tank.

 Bb floats, most other species don't. Therefore, by having deep ponds, there won't be much light on the bottom for light to reach and help competing species grow. The same for not having much turbulence - the Bb doesn't need it so much, as it's a surface dweller, while the competition does.

The first year, we are going to grow just a summer crop. So, we don't need to spend money on covering the pond. In later years, when we have more capital, we will enclose it with either plastic sheeting or solid panes. At that time, we will also have blowers to circulate air from the outside, for both the introduction of CO2 and for temperature control.

Skimming is the easiest way to get the floating Bb off the surface. If any Bb is below the surface, that's because it doesn't have enough oil to float and therefore isn't ready for harvesting anyhow. It has been proven that hexane can be used as a solvent without killing the Bb. This is because the majority of the oil that Bb creates is extracellular. That's why we return it to the pond - because it's job isn't done yet. We've just sheared it like a sheep. It's also why we don't treat the Bb roughly, because we want a good portion of it to survive the harvesting of the oil. Of course, there will be some that won't, but we depend on the addition from the PBR along with natural reproduction to keep the numbers high. We also aren't so greatly concerned with getting every last bit of oil, because it will come around again, eventually, anyhow.

 As I see it, our biggest problem will be with temperature control. This plant will operate in New England, which has a wide range of temperatures.

 

Comments on the design?
 

 

Very interesting write-up. If you can, please post pictures at some point, and keep us updated. Thanks.

Now that is an intersting post. Thank you very much.

I am looking at a semi closed PBR design and am considering BB as a stock. To get optimum production though you will need to provide optimum levels of lighting, co2 injection, nutrient supply and temperature control.

I should have the pilot plant up and running by the end of Feb but will start with spirulina, only because I have a market for the product and will use the cash flow to improve and iron out kinks before starting full production.

My system will operate indoors so control of the environment is no problem. Whilst providing artificial light may be regarded by some as a negative, optimum lipid production is the aim and higher production levels will off set any energy "waste".

But then again, my end goal aim to use on site generators, using glycerol as a fuel, so it will be an environmentally friendly self supporting system.

Keep us up to speed with your progress.

In regards to levels of lighting, CO2, and nutrients - you are correct that there will be far better growth when these are supplied at an optimum level for the algae. However, that specific level may not the be most economically efficient. Where land is cheap in comparison to equipment, it makes sense to settle for slower algae growth in order to save money. Where land is more expensive, or where there is a significant CO2 stream to take advantage of, it makes sense to spend the money on the extras. I suggest that you do some research in lighting, as you'll want to have efficient lighting, at the right spectrum for the algae.

Yeah, I am looking at the lighting issue at the moment. Phillips have just brought out the TL5 HE range of flouro tubes with electronic ballast that is dimmable and has instant "on".

I intend trialing the flash sequenceing method in my PBR.

 

If it´s about growing spirulina for human food, and the price is high, you may make a profit moneywise. Just another case of foodproduction with an inverted energy input/output.

But it is definitely not in the scope of this forum to produce less (energy) from more.

As long as the total energy for photosynthesys + the process energy are > net energy output, we are not going anywhere ecologically.

As simple as that ! 

That's why I am looking at the Phillips units - they are meant to be high efficiency but with the on off cycling I will use less energy than if I were to use fluoros full time or even, sun plus fluoro over night.

Right now I do not know how to calculate the energy efficiency of the whole project but believe it will, by using my own generator, burning my own fuel, made from my own algae will be very energy efficient (is that the right word?). 

Flourescent lights are cheap to buy, but you may not be getting the best value. Plants differ in the spectrum of light they need, and also differ in their requirements at various points in the growth cycle. It would be best to figure out what spectrum is best at each given time, and whether it is better to use special High-Pressure Sodium, or Halogen, or Florescent. etc. Some of the hydroponics web sites may be good for pricing out the lamp, but we still need to know the spectrum for the chosen strain of algae.

bobk:

The PBR is to have a reserve of Bb, in case of infection by an undesireable organism. By constantly adding the Bb, we keep its population high enough so as not to give other species an opportunity to get a foothold. If an invasion happens anyhow, we disenfect the pond and seed again with Bb from the development tank.

I think you are in for a rude awakening as far as how quickly the pond is taken over by low oil strains. Bb is incredibly slow growing, making it easy for low oil strains to take over.

 Bb floats, most other species don't. Therefore, by having deep ponds, there won't be much light on the bottom for light to reach and help competing species grow. The same for not having much turbulence - the Bb doesn't need it so much, as it's a surface dweller, while the competition does.

I think your logic is flawed there. Needing turbulence or not has nothing to do with whether the algae is a surface dweller really (and it's also faulty to think that most other species won't reside on the surface). Regardless of whether the strain floats or not, if there is no turbulence, only the algae near the top get any light, as soon as there is a fairly dense culture. The turbulence is to circulate the algae vertically. Bb floating does not negate the need for that.

The first year, we are going to grow just a summer crop. So, we don't need to spend money on covering the pond. In later years, when we have more capital, we will enclose it with either plastic sheeting or solid panes. At that time, we will also have blowers to circulate air from the outside, for both the introduction of CO2 and for temperature control.

So you're not planning on doing any aerating initially?

Skimming is the easiest way to get the floating Bb off the surface. If any Bb is below the surface, that's because it doesn't have enough oil to float and therefore isn't ready for harvesting anyhow. It has been proven that hexane can be used as a solvent without killing the Bb. This is because the majority of the oil that Bb creates is extracellular. That's why we return it to the pond - because it's job isn't done yet. We've just sheared it like a sheep.

So does that mean you aren't going to be drying the Bb before oil extraction?

 Who proved that you can extract oil from Bb with hexane without killing it?

Slippery:

Now that is an intersting post. Thank you very much.

I am looking at a semi closed PBR design and am considering BB as a stock. To get optimum production though you will need to provide optimum levels of lighting, co2 injection, nutrient supply and temperature control.

I should have the pilot plant up and running by the end of Feb but will start with spirulina, only because I have a market for the product and will use the cash flow to improve and iron out kinks before starting full production.

My system will operate indoors so control of the environment is no problem. Whilst providing artificial light may be regarded by some as a negative, optimum lipid production is the aim and higher production levels will off set any energy "waste".

If your goal is producing fuel, using artificial lighting is incredibly inefficient and uneconomical. Let's say you use some magic new kind of fluorescent light that's much more efficient than current ones, that can somehow convert 20% of the electricity into light, and all of that light is in the photosynthetically active region (PAR). At best then, with everything designed perfectly, you could get perhaps a bit under a 25% efficiency for harvesting that light (since it's all in the PAR region, compared to natural sunlight, for which only 45% is in PAR). Let's say that 60% of the biomass is oil, and you can convert it to biodiesel with 100% efficiency. At best then, you would have a 20%*25%*60*= 03% conversion of electric energy into biodiesel, with 2% of the energy being converted to other biomass, and the remaining 95% of the energy lost.

And that's assmuming some unrealistically high efficiencies.

Now, why exactly would you want to do this? And how exactly would the higher oil yield make up for wasting 95% of the energy (in reality it would be more like 98%).

But then again, my end goal aim to use on site generators, using glycerol as a fuel, so it will be an environmentally friendly self supporting system.

Ok, this introduces another inefficiency. Let's say the generator operates at 40% efficiency for converting fuel energy to electricity (again unrealistically high). Then your net efficiency from converting that liquid fuel energy (as glycerol) to liquid fuel energy as biodiesel is now 3%*40% = 1.2%. Given the efficiencies, you would need to burn the energy equivalent of 83.3 gallons of biodiesel (glycerol with the energy equivalent of that much biodiesel) to produce 1 gallon of biodiesel. Wow, an energy balance of 0.012. Pimentel would have a field day.

Even if you could get that glycerol for 10 cents per biodiesel-gallon-equivalent (unrealistic), just the fuel needed for the artificial lighting would cost you $8.33 per gallon of biodiesel produced.

I don't mean to sound so pessimistic, but using artificial lighting to grow crops to make fuel is just incredibly inefficient and impractical.

Slippery:

That's why I am looking at the Phillips units - they are meant to be high efficiency but with the on off cycling I will use less energy than if I were to use fluoros full time or even, sun plus fluoro over night.

Right now I do not know how to calculate the energy efficiency of the whole project but believe it will, by using my own generator, burning my own fuel, made from my own algae will be very energy efficient (is that the right word?). 

Nope, that's not the right word. The right word would be "inefficient", not "efficient".

bobk:

Flourescent lights are cheap to buy, but you may not be getting the best value. Plants differ in the spectrum of light they need, and also differ in their requirements at various points in the growth cycle. It would be best to figure out what spectrum is best at each given time, and whether it is better to use special High-Pressure Sodium, or Halogen, or Florescent. etc. Some of the hydroponics web sites may be good for pricing out the lamp, but we still need to know the spectrum for the chosen strain of algae.

All plants can only use light within the narrow photosynthetically active region. Exactly which parts of that region they prefer depends on how much of different pigments they have. But, almost all plants have a fair amount of pigments in each part of the PAR.

how hardy is BB? I was told that it is extremely prone to contamination (even more so than most species). Is this really true?

I suggest examining the local native wild algae- they will undoubtedly yield a lot less oil (if any), but here's a "for instance": in Santa Rosa, a team of researchers that I am working with found that the extremely hardy local species would *only* yield 874 gallons per acre. Hey, I can live with that.

ybiofuels:

I suggest examining the local native wild algae- they will undoubtedly yield a lot less oil (if any), but here's a "for instance": in Santa Rosa, a team of researchers that I am working with found that the extremely hardy local species would *only* yield 874 gallons per acre. Hey, I can live with that.

and local algaes from local sources can have a second benefit of non-point pollution control. an algae filled lake has a ready source of feedstock as well as a value to remove them. win-win.

Anonymous123:

how hardy is BB? I was told that it is extremely prone to contamination (even more so than most species). Is this really true?

my 2 cents

the less hardy a species is, the more issues one is going to have growing it. so if someone is out there trying to get as much oil algae by selection, then necessarily that ecosystem becomes less stable and hardy (a big sack of oil doesnt stand a chance against local weed solar harvesting machine). so cultivation (cost) increases as hardyness decreases. cultivation the major expense in ag and i could imagine that a PBR dwarf's that typical ag% because of the technology needed.

wild algae = low cultivation costs(heck, my local lake is a negative cultivation cost because they will pay me to take it out). hi tech/yield photobioreactors = hi cultivation costs. i could imagine that the highest yielding Bb would also be most likely not hardy without intense cultivation (which means costs).

im just into low hanging fruit. i dont see a backyard photobioreactor low hanging fruit, its much more of a research project than fruit, presently at least. or at least using a local wild algae and 'tweaking' it would be a middle ground.

 

Sorry - I am not so good at inserting yhe quotes on this forum:-

Mike, you said:-

Nope, that's not the right word. The right word would be "inefficient", not "efficient".

OK, I am trying to get my head around that. Lets see, if it does not use only sunlight and natural inputs, it is energy efficient. 

As soon as you have to add external ingredients, be they light, CO2 or pig manure, by your reasoning, the venture is energy inefficient.

 That sounds like one should not spend money to make money because by spending money you are wasting it (thats actually my wifes philosophy to).

I would think a venture would become energy inefficient only when the sum of inputs exceeded the value of outputs.

In any PBR or raceway system being used to produce BD, the net energy outputs, represented by the energy value of the BD must surely far exceed the net energy inputs.

 

 

Anonymous123:

how hardy is BB? I was told that it is extremely prone to contamination (even more so than most species). Is this really true?

Yes - because it is extremely slow growing. Being prone to contamination isn't because of it not being "hardy" though, it's because it grows slowly (in general, the higher the oil content, the slower it grows, because it has to expend more energy making oil) - which is why low oil strains take over open systems.

Slippery:

Sorry - I am not so good at inserting yhe quotes on this forum:-

Mike, you said:-

Nope, that's not the right word. The right word would be "inefficient", not "efficient".

OK, I am trying to get my head around that. Lets see, if it does not use only sunlight and natural inputs, it is energy efficient. 

As soon as you have to add external ingredients, be they light, CO2 or pig manure, by your reasoning, the venture is energy inefficient.

No, that is *not* what I said, and not what my reasoning is. I said you should not use artificial lighting - how can you equate that to me saying that you shouldn't add "external ingredients,  be they light, CO2 or pig manure"? Seriously?

I explained why using artificial lighting is inefficient. Read it again. That has nothing to do with using pig manure or CO2.  

That sounds like one should not spend money to make money because by spending money you are wasting it (thats actually my wifes philosophy to).

No, my philosophy is you shouldn't spend $80 to try to make something that you hope to sell for $2. If you disagree, then by all means go ahead and do it.

I would think a venture would become energy inefficient only when the sum of inputs exceeded the value of outputs.

Yup. And because of the incredible inefficiency of using artificial lighting for photosynthesis, no matter what else you do, your energy inputs will exceed your energy outputs. Look at the efficiencies again. All biofuels projects get the energy that goes into the fuel from photosynthesis. If you let the sun provide the photons, then you can say that that energy input is "free" - we don't power the sun. As soon as you start providing those photons though with artificial lighting, you need to start looking at how efficiently you can make the light (and how efficiently you make the electricity to make the light), and how efficiently it gets turned into biomass. The overall process is very inefficient, as I explained - well over 90% of the energy in the fuel you burn to make electricity is lost (as heat), in the process of making biomass. We can accept the low efficiency of photosynthesis (roughly 12.8% best case for turning photons from sunlight into chemical energy) - if those photons are coming from the sun. But not if we make them.

In any PBR or raceway system being used to produce BD, the net energy outputs, represented by the energy value of the BD must surely far exceed the net energy inputs.

If you use the sun for lighting. Not if you use artificial lighting. If you want to go based on an assumption rather than actual numbers and calculations though, by all means try it out. Let us know how much money you lose.

 

we discarded the notion of using BB a while back in fact we didnt even have it in our inventory of algae type cultures( although we will be adding it soon ),mainly because it is  reputed to be toxic to fish and other aquatic organisms so it wouldnt work in our symbiotic systems also, because the oils produced by BB are complex and reputed to be difficult to process into biodiesel, we have done considerable work with lighting and have discarded that notion also although we have lighting installed for those long cloudy winter days but never for continious use even  office cool white flourescents use quite a bit of power and certainly  sodium lights used in hydroponic scenarios are prone to consume prohibitively high power something that we  detest and have gone all out to prevent, we do however love photovoltaics and inverters coupled with small multifueled engines running 100 charging amp alternators to take 12 volts  up to 5000 watts of 110 to run  our blowers and pumps in case of power failure.  in fact our whole facility, the biodiesel plant, the lab,the house, the conference center and the closed loop ecosystem are set up in such a way that the monthly power bill is negligable less than 1200 kwh per billing period and soon well be intertied so we can feed power back to the grid with our cogeneration facility and get paid 10 cents per kw through the Green power switch incentive program that we enjoy here in tennessee where  we pay six cents per kwh  and the utility system pays 16 cents per kwh for buyback of power generated and fed back to the grid. a sweet deal indeed so when we finally have that intertie set up well pay even less for our power to run the whole" kit and kaboodle" that is ecogenics. now we do light  the laboratory 24/7 with cool white flourescents since we have found that the algae thrive on it we do modulate the light by screening it for some cultures and we have one type of algae that doesnt need  very much light at all also it seems that we have acclimated both the fish and the al;gae in the closed loop to live and grow in 56F water in fact our tilapia ecogenics have just spawned and we have been having a fairly cool spell this last few days. but the pond maintains 56F  through geothermal heating which occurrs at the depth at which we dig our ponds. of course our "tilapia Ecogenica" hybrids are unlike  other tilapia that can die quickly at those temperatures because they havent been aclimated as ours have over the thirty years that our fish have been continiously raised in our system. the same holds true for our algae which has been acclimated to lower temps as well. the density of our algae in the pond averages 1/4- inch  secchi disk reading most of the time making it hard to see the Tilapia except when they rise up to peep at us out of curiosity. the bottom line is the energy input equation is crucial to the successfull production of algae and biofuels all measures must be taken to ensure a positive energy balance in our distillation system we  use jacketed columns into which we inject steam this heats the whole column from top to bottom and saves a huge amount of energy and makes the distillation process highly efficient. in a conventional distillation system a process called counterfolw is used... live steam is sparges at the bottom and the mash is introduced at the top of the column and as the mash makes its way along the perforated plates trhat have little dams built into them to increase the dwell time of the mash it meets the steam which boildls off the alcohol which is  entrained in the mash since the columns are not evenly heated "flooding occurrs due to cool spots and uneven heating of the columns and this makes ethanol production far more energy intensive than if the provisions we designed into our system are used in the columns... another trick of ours is to throw a vaccuum on to the columns this lowers the boiling point of the alcohol from 174.9F to 165F. ergo less energy is used. another advantage is that we can make USP pharmaceutical grade alcohol in our distillery this product is dramatically more profitable than fuel alcohol we have used our organically certified USP grade pharmaceutical to make extracts and tinctures out of our hydroponically grown organically certified herbs for as much as  50 dollars per ounce in the past. the purity of our alcohol is attained because no water comes into contact in the form of steam through out our distillation process. another factor is the choice of fuels to run the  facility must be  redundant and made on site.. using the spent mash to feed hogs allows us to have a methane digestor which supplements the gas used in the plant to run the boiler which is a closed loop system that recovers  all the water and recycles it back into the boiler if not for that we couldnt operate here because we are on a well, not city water so saving water is a must. anyhow energy inputs are the most crucial factor to ensure the success of alternative energy production systems as are having a cascading stream of value added products to in effect make the production of fuels a by product of the whole scheme. therefore selling biofuels at a lower price than petro fuels becomes tantilizingly possible if systems such as ours were to be  utilised instead of the ones used in current production practices which are energy intensive and make alternative fuels implementation a tenious proposition at best at this time...

 www.ecogenicsresearchcenter.org

marc