In this instructable we will go over how to construct an at-home version of a photo-bioreactor which will use solar energy and artificial lighting with carbon dioxide to produce algae biomass.
The aim of this project is to create an model which harbors an ecosystem fit to help us escape a fossil fuel economy. We are in an era that is experiencing a shift from humanity trying to dominate nature, to then trying to preserve parts of nature and now trying to reach a reconciliation with nature. This is the algae experiment; an idea that is trying to move away from a linear wasteful and polluting way of using resources to a closed loop system where all resources are kept in a closed loop cycle.
Follow the possibilities of harvesting algae for fuel & see the difficulties met along this journey on-line at
@@@: thealgaeexperiment.tumblr.com
a published paper on the subject can be found on
@@@: http://issuu.com/mouchmouch/docs/thealgaeexperiment
The aim of this project is to create an model which harbors an ecosystem fit to help us escape a fossil fuel economy. We are in an era that is experiencing a shift from humanity trying to dominate nature, to then trying to preserve parts of nature and now trying to reach a reconciliation with nature. This is the algae experiment; an idea that is trying to move away from a linear wasteful and polluting way of using resources to a closed loop system where all resources are kept in a closed loop cycle.
Follow the possibilities of harvesting algae for fuel & see the difficulties met along this journey on-line at
@@@: thealgaeexperiment.tumblr.com
a published paper on the subject can be found on
@@@: http://issuu.com/mouchmouch/docs/thealgaeexperiment
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The over all shape of the photo bioreactor is inspired from a previous project I had been working on where it follows a mean summer solar path of the UK. It is meant to be both an educational model but also embody certain architectural elements within allowing it to possibly be viewed as an informational pavilion.
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If you would like to read more I have published a paper on the whole project on issuu.
http://issuu.com/mouchmouch/docs/thealgaeexperiment
I've been looking at using the extracted algae oil (and any other cheap and/or waste veg or animal oil/fat triglyceride) as 'green diesel', different from 'biodiesel'.
Biodiesel is typically fatty acid methyl ester (FAME), made by reacting veg oil with lye (hydroxide) and methanol, yielding stuff that can be used in place of diesel fuel. Advantage: easy to convert in a backyard barrel, good lubricating properties; Disadvantage: can 'gum up' due to other double bonds elsewhere in the fatty chain, like varnish, thus destroying most fuel injectors, pumps, etc. Also, a more powerful solvent than regular diesel, so need viton fuel lines, gaskets, etc., and better fuel filters because the FAME tends to dissolve all the crud in the tanker, storage tank, transfer lines, your fuel tank, sending all the gunk straight to your filter, or worse, injectors. Nasty.
'Green diesel' is diesel made from renewable sources like veg oil. Can be made by hydrotreating veg oil using a Ni-Mo catalyst at maybe 300'C and 50 Atm pressure, not unlike making margarine, but more so. Adv: very high 'cetane' rating (like 'octane' for petrol / gasoline) at maybe 95 cf. 'regular' diesel at 51 cetane rating. Can therefore be used to blend into low grade diesel. Hydrotreating with hydrogen gas can fully saturate double bonds in the fatty chain that would otherwise lead to gumming up.
Oh, yeah, great that you're using the natural floatation of the algae to enrich for species / strains that yield lots of oil and oxygen! Ideally the whole reactor tube system would use both the thermosiphon effect (heating up on exposure to sunlight) and the decrease in cell density due to oil and gas accumulation to help circulate the algae through the pipes.
Keep us all posted on how it's going, m0uch!
PS, would it ice up in winter over your way?
Lots of good additional information for an already great Instructable - thanks!
I was wondering about people running used fryer oil from restaurants in their diesel powered cars; as I understand it, all they generally do is filter it to remove food particles. From what you say, though, it seems that if they used fresh veggy oil they would run into problems. Is the fryer oil actually improved because it's used? I'm guessing something like the high heat and the H2O boiling off from the food while it's cooking is doing something to modify the oil's composition? If so, that's pretty cool that you get two uses out of a renewable resource, with the first use improving it for the second use! (Unlike diesel, which no one wants their fries boiled in :-)
I had to look it up. It's funny, what they told me at uni years ago was that fats/oils get hydrogenated or at least lose their polyunsaturated 'goodness' after being heated for a while... i.e., used for cooking.
So my lecturer in biochem reckoned that polyunsat oils were really no better than sat fats like palm oil, coconut oil, etc.
However, this was at odds with what I also knew from chem eng in that hydrogenation, to be efficient, requires higher temps (300'C), pressures (2.5 atm), H2 gas, a catalyst like Nickel or Copper complexes on a silica or alumina (or both) support (really just wee ceramic beads usually).
Here! http://www.brevardbiodiesel.org/iv.html
The Iodine value is an indication of how unsaturated the oil is, and usually equated with how unstable it is, but others have indicated this is not always the case. An unstable oil is not what you want to put through your high pressure common rail fuel system and injectors, esp. if running a sweeeeet sweet VW golf series5 2.0 L TDI... as I am ;-)
The common rail system gets up to over 1000 atm, a recipe for all sorts of chemical craziness to bust out.
Does look like the longer an oil is used for cooking, the more 'burnt' and partially oxidised it normally becomes, but not nec. a great reduction in the double-bonds that are the 'unsaturated' or high Iodine number factors that I thought would lead to chemical unstability, gelling, gumming of the injectors, burning / coking of the injectors and cylinders, etc.
Personally, before I stick it into my sweet ride, you test it on yours and let me know how you go (and IF you go) ;-)
Otherwise, I've been toying with the idea of using hydrogenation reactors and Ni-Mo catalysts to clean up algae oil, waste veg oil, grease trap gunk, and turn it into chemically stable fully saturated and low S, O, P, N oil more like petroleum derived diesel, or 'green diesel' rather than 'biodiesel' fatty acid methyl esters (FAME).
W
Cool model, and nice instructable! could you share a little more on why you made this bioreactor?
http://issuu.com/mouchmouch/docs/fuelcartridge
Overall I wanted create a piece which would be able to show people that anyone could start growing algae for the purpose of bio-fuels at home. This is not to say that it's either easy nor 100% feasible however it did provide food for thought for the people who attended the exhibition which I hosted in the UK.
I know the extraction part is the 'hardest' part although growing the algae in large, effective quantities in itself is the first step..
Could the algae and their byproduct not be used as a free fertilizer? I assume that the algae would be a great form of biomass and the natural gas byproduct would be full of nitrogen?
Instead of fueling a car your fueling your home garden.
Please let me know if i'm out to lunch or bang on?
If i'm right I guess this is food for thought?
Yes the algae can be used for diverse reasons, although once used for its oil extracting purposes it can also be used as something else, usually livestock food because it is rich in nutrients. However, as I am not a scientist I cannot confirm about your nitrogen query. I will look into it and reply back.
Use of human wastes and effluent could work, but tends to have too much Sodium and not enough Potassium. Use of a worm farm and composting from garden, market and agricultural waste can work, but does require manual labour and quite a bit of tricky balancing.
In New Zealand, they're using an algae reactor to treat sewage, but will have to wait to see the results in a year or two. Sometimes these things seem OK to begin, but can 'wash out' over time, being overgrown with non-productive organisms, or even 'predator' organisms like Amoebae.
http://www.niwa.co.nz/publications/wa/vol13-no4-december-2005/energy-from-wastewater-treatment
as yeast requires sugar to crate CO2, and in that process it creates alcohol, witch would probably harm algae
but during research I found that Schiochytrium algae would give higher theoretical yield
why aren't you using that algae?
I never came across this strain of algae that you are referring to. However the reason I chose B. Braunii is because from the location I procured the algae from it was either that species or the N.Occulata species and the Braunii typically has very high oil yields as it is. I am in talks though to obtain more strains of algae in order to do further testing. I will look into the Schizochytrium strain. Thank you for the information.
I am starting my bioreactor very soon =D
I am wondering about he design - Wikipedia refers to it as "Tubular photobioreactor", but also it says that it is rather inefficient (when you think about it it is logical as most of CO2 gets used up in first tubes)
so I am trying to avoid that problem, maybe if the air is introduced in multiple points?
Anyway for beginning I believe I'll start with "Bubble column bioreactor"
Elegant solution as to the placement of the tubes to get maximum solar exposure.
Yes, there is some interest in using microalgae to produce oil for biodiesel / green diesel and cosmetics/pharmaceuticals, with the algae cell debris pellet for use as cattle feed. The advantage being that it is some thousands of times more efficient per hectare land area at converting CO2 into biomass than current plant crops. Also, given it is inedible, it does not compete in the 'food-or-fuel' dilemma discussed of palm oil.
Check out MBD Energy for the biosequestration of CO2 from coal fired power station emissions.
Actually, some microalgae *do* fix nitrogen under some conditions, mainly low nitrogen, forming 'heterocysts' or lumps to keep out oxygen that otherwise stuffs up the N fixing enzymes. Anabaena is one http://en.wikipedia.org/wiki/Anabaena.
Also, one can extract the oil then compost the cell debris and 'recycle' the inorganic nutrients like N, P, K, S, Fe, Mg, etc., but yes the use of fertiliser is a significant energetic input considering about 1% of the world's energy consumption is fixing N via the Haber process.
Er, also, one problem that many algae species suffer is that they don't like really bright light. Ironic, eh?
This might not be such a problem after a couple of weeks of operation as the insides of the tubes will be coated with biofilm and gunk anyway, so it will reduce the amount of light reaching the algae. Use of silicones like silcote can make the insides of the pipes less sticky.
Use of a small solar PV cell to power your pump is good, as also setting it all up as a solar thermosiphon to minimise power consumption from pumping water through a narrow pipe.
Good work! I might give it a go myself!
W
Thank you for your comment, I hope you do give it a go, I would love to see the result :) Yes you are correct about using the solar PV cell to power the pump, the only reason I did not use it was because of funding issues.
Let me know if you need any help.
Charles
Years ago I sketched out an idea for what I called a "Human Nitrogen-Recycling Reactor" (HNRR). Essentially, the idea was to convert human urine into usable nitrogen fertilizer.
For several thousand years, Chinese farmers and gardeners would pour their urine into a barrel to let it "ripen." They would then pour the fertilizer on their intensively-gardened plots. The Chinese who came to California during the Gold Rush, using the same pee barrels, found they could make more money by selling fresh produce, intensively gardened and piss-fertilized, to American miners, some of whom were known to spend a day's worth of gold on a single egg or head of collard greens.
My HNRR would run as a semi-closed system so that the volatile ammonia (readily detectable by the nose) would not be lost. Instead it would be redissolved back into the "effluent" (a reasonable euphemism for piss). The effluent would then be cycled through a medium (plastic balls, gravel, etc.) in which dissolved ammonia would be converted to usable nitrate by ammonia-eating bacteria that naturally take up residence in the medium.
The use of ammonia-loving bacteria (to each his own, I suppose) is the core of the process. That's the already well-proved part--it's how ammonia (toxic to fish) is converted in ordinary aquarium filter pumps to better-tolerated nitrate.
In the HNRR, at some point (not all that long) the batch of piss would be fully reduced to garden-ready liquid fertilizer.
Two issues I never got around to resolving. The first was more psychological than real: it's urine (!!) so how does it not present a health hazard? Tests would have to be made, but frankly I think the high levels of dissolved ammonia present at the beginning of the process would sterilize infectious bacteria and viruses. Those are not typically present in human urine anyway except in the case of an infectious disease such as a cold, flu, or obviously, an infection of the urinary tract.
The other issue was that the reactor would run, by it's nature, in a batch mode rather than a continuous one. That would complicate using the thing. Do you store the pee before running a full batch? Maybe. To make the process continuous end-to-end---dump piss into one end as it's produced in the household and collect converted liquid nitrate fertilizer at the other end--would be a real challenge. It would certainly make the HNRR more complicated (and costly).
I suppose another issue would be how to collect the urine. Chamber pots? Empty milk jugs?
You know, I might just dig out my notes on all that. Nerds like me keep things like that. Thanks for the inspiration!
Todd
I'd say collect and pour in till the first batch container is full. Have a few reactors going at the same time. Distillation and crystallization would be an interesting challenge to get solid nitrates. Though separation of the nitrates from the phosphates and other minerals might prove to be a bit of a challenge as well.
I've tried collecting mine for other experiments and have found that milk bottles and Powerade/Gatorade bottles are good to since they have a larger cap and mouth. Makes for an easier fit and less splashing.