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Is Fresh-Water Cultivation of Algae Feasible.. 12

I was reading the algae news and see a university trying to research on Botyrococcus braunii. But what is the whole point of researching on a fresh-water strain when we know this ain't gonna be feasible economically..

http://www.walesonline.co.uk/news/wales-news/2010/12/15/can-algoil-help-to-fuel-wales-prosperity-91466-27827784/

In addition I also read Narsi 's mailing list today from Oilgae  and he exclaims that that it requires about 1 million liters of water to produce on 1 dry ton of algal biomass.  So how is fresh-water going to work? Wondering!!!!

Wed December 15 2010 12:27:05 PM by Monterio algae  |  fresh-water 2904 views

Comments - 12

  • Arden wrote:
    Wed December 15 2010 05:39:38 PM

    Fresh water is a no no.

    Either salt water or  waste water treatment .

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  • Vivek wrote:
    Thu December 16 2010 04:38:35 AM

    I am With Arden, Growing Algae for Biodiesel at large scale in fresh water is not possible as in Many parts of the world we have Water Scarcity...

       And If People will waste fresh water in this way then I feel in the Coming time,We will have to talk about Water as the biggest problem,as we are taking Diesel & Petrol today..

      It can be done with Sea-water or waste water treatment...

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  • Lucygreen wrote:
    Thu December 16 2010 10:04:58 AM

    Is it possible to co-;locate all the algae cultivation ponds near the sea.. Is there so much land availability near the sea? What about the pumping cost of sea-water and if the pond is very far away from the sea, how can the transport of sea-water be done . even if we use steel pipes, the shelf-life of the pipes will be less than ten years the pipes will be corroded due to salinity.. So, wont that increase the costs?

    And definitely fresh-water is ruled out!  In my opinion waste water is a better option!

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  • Thu December 16 2010 12:19:37 PM

    I would say if it takes 1,000,000 liters to produce 1 tonne of dry algae, someone better check for leaks!

    What are you doing with all that water when the algae have been harvested???   You should recondition and recycle it back to the input end of your PBR. 

    Show the numbers!  Where is all this water going?

    Alan

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  • LG4NRG wrote:
    Thu December 16 2010 07:08:40 PM

    Many interesting points on sustainabillity in this discussion!

    First of all, of course one has to be carefull to generalize too much, saying freshwater is a no-no is a bit too strict, but when talking about full-scale biofuel production, i.e. 1000s of hectares, there are only few locations where sufficient fresh water is available, using an open system, because of water losses due to evaporation. Closed systems will have reduced evaporation, so water can (and should) be recycled. I am convinced that big-scale algae production will produce more than just biofuels, animal feed for instance, which may restrict the use of salt water. But in that scenario, meat eaters are responsible for a big part of the water use by algae, not just car owners :o)

    Secondly, Botyrococcus braunii is a fresh water alga, but grows well in saline water. Seawater (0.35% salt) is too salty, it limits, but doesn't stop B. Braunii's growth.

    Third point, there is an important option between fresh water and seawater! Many of the world's aquifers are too salty for agriculture. A few are used for powerplant cooling, so the technology exists, but consumtion is very low. Then there are estuaries where fresh water mixes with (tidal) seawater, so low salt concentration, but a very large supply, currently untapped.

    Lucy has a valid point that seawater is more corrosive, but this is no real bottleneck, saltwater transport is certainly not a new technology. What is the point here is the energy consumption of long distance water transport. A great example here is the (Mauretanian part of the) Sahara desert; it is actually below sea level, so in theory no pumping required.

    Fifth point by Lucy, land availabillity, I read earlier this week that China alone has 17 million hectares of land that is too saline for agriculture...

    Last point, Alan, I think you already sense that the 1000 tonne of water is not "spent" growing the 1 tonne dry biomass, at least a part will be recycled, for economic reasons, not just environmental. How much depends on many factors, but there is a general (economics-motivated) trend to try to get the algae to float, flocculate or settle, so only a minor part of these 1.000.000 liters actually passes the harvesting process.

    Cheers, Sjors

     

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  • Sat December 18 2010 05:26:12 AM

    Sjors,

    It looks like he is producing only about 1 gram of algae per liter of water used.  Is that close?

    If so, it seems like pretty thin 'soup'!

    Alan

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  • Tue December 21 2010 02:23:05 AM

    How many grams are possible per litre of water ?

    5 grams ?

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  • Fri December 24 2010 12:27:58 PM

    Mia,

    Yes it is possible to harvest many grams of algae per liter in a 24 hour period.  The trick is to harvest that litre at least 6 times per day.  Take some and leave some.  But always keep the remaining algae in the reactor in perfect growing conditions.  There are research companies that are working towards developing algae or "whatever" to double in just a hour or two. 

    If you look back in my blogs of, I think about May, you will find where I am talking about harvesting ~30 grams per litre capacity.  Now you know how we will be doing that.  We harvest that litre many times per day.

    Alan Schaefer

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  • Sat January 01 2011 06:43:26 AM

    Hi Alan,

    Harvesting 30 grams algae/Liter-Day looks fantastic to me. Is this dry or wet algae ?

    Another question: Assuming 12 hours of sunlight at 100 watts / sq. meter, and no other rate limiting steps, what's the maximum algae can you produce/harvest per liter per day ?  (You can make specific and resonable assumptions if you want to.)

    Are there data on the kinetics and thermodynamics of algal "growth phase" and "oil production" phase ? (Again, assumptions are acceptable to get an idea on the kinetics and thermodynamics of a specific algae, media and conditions used.)

    Mario D. Castillo (mdcastillo1942)

     

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  • Shankar wrote:
    Mon January 03 2011 02:03:32 AM


    30 l per day seems very very good. 

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  • Thu January 06 2011 06:06:42 AM

    Mario & Shankar,

    From past blogs you know that we use million gallon, bunker type, concrete tanks.  The algae mix is lit by LEDs from top to bottom, about 20 feet in depth.  Our LEDs of coarse are the 'right' color and flash....very fast.  They are 'on' about 10% of the time so our light bill is very reasonable.  The algae are growing at max rate 24/7/365.  Also as stated above we harvest that liter many times per day.  ( Just one harvest of a million gallons per day is 694 gallons per minute.)To meet our goal of 30 dry grams of biomass per day per liter capicity we need to harvest about 6 grams every  5 hours.  

    We are more interested in maximum 'mass' rather then maximum 'oil' in the PBR.

    When we are operating at near 100% a 1,000,000 gallon PBR will mitigate 4,000 cfm  CO2.

    Alan Schaefer

     

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  • Tue April 10 2012 06:11:18 AM

    Cultivation of algae in fresh water is feasible if it is possible to convert salt water to fresh water in a large scale. At present, fresh water scarcity is increasing at many parts of the globe. Therefore, it is highly necessary to convert salt water to fresh water for successful algal biomass production.

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