Narsi, the second law of thermodynamics apply when we put energy to work (Entropy). So when we force (high Entropy) algae to do a CO2 clean-up work (CCS in a limited size/concentrated area such as a PBR) behind an exhaust pipe, will require a high quality energy to be "wasted" in the process. A lower Entropy approach (releasing CO2 in a larger dissipation area) will create a balanced system with a minimum waste or extra energy. Algae, by any definition is not a machine.

Direct CO2 capture is not possible easily.We have to know solubility of CO2 at various tempratures,pressure and at different pH values then we have to convert in to carbonate or biacarbonate in absence of Ca & Mg ions will have add as feed to growth bioreactor just we use in fermentation process.

My apologies...the earlier comment was inserted before I could finish it!

Having looked at ALL POSSIBLE WAYS of CO2 capture and sequestration, I think algae-based process, while very challenging right now, might possibly be one of the very few (or possibly the ONLY one) method that is relatively more viable than all the other even more unviable prospects...let's only hope that more R&D $ and a lot of passion make algae-based capture more viable feasible in future...

Thanks to all of you for your very insightful comments...

To just let you know, we had been doing a good amount of research review on each and every aspect of algae-based CO2

The current technology and status of algae biomass production for CO2 sequestration is pilot stage/early commercial production. This doesn't seem like the right time to approach large CO2 emitters for sequestration options. They are looking at the bottom line, utilizing commercial-ready systems, and algae is still on the brink and too highly debated a topic for a separate industry to jump into (ie cement, power, etc.).

However, I am finding that smaller sources of CO2 (eg 12MW power plants and smaller) are much more receptive of the possibilities for algae. Financing also seems facilitated by smaller project size. For example, I am finding local grant and financing sources are interested, even eager, to be involved in such "green" projects. Community-size interest and involvement may offer the enthusiasm to generate algae-based CO2 capture at small industrial plants. Therefore, smaller systems may be our proving ground and a means to "step up" to large emitters. Some of you may say that the "proof" has already been submitted and algae is ready for large sequestration projects. There may be proof enough for us enthusiasts, but is it enough to gain the interest and pocket-book of large industries? I believe they are waiting to see the outcome of the existing projects (ie MBD energy, et al).

There are a great variety of CO2 emitters, as well as CO emitters and each has its unique opportunities for algae sequestration. Has anyone encountered any CO emitters for sequestration? CO must, of course, be converted to CO2. It is possible to use steam and CO to create SynGas and CO2 and use algae for sequestration, but I am not aware of who may be working on just such a system. Do any of you FOA have any knowledge about CO conversion and sequestration?

Say for eg, if we try to supply CO2 from an industry flue gas how we specifically send in CO2 and avoid the other gases for the algal bloom. This is a great challenge from my point of view.

Robert is right about the sense of frustration one gets when trying to get large corporations to move towards a better way of doing something. They seem perfectly happy to ignore a profitable solution to their problems and pay someone to solve those problems some other way. Pumping CO² underground as a gas it downright stupid. Just because it doesn't leak out in the first 5 months, or 5 years or whatever criterion they apply, doesn't mean it won't get out eventually. Reacting it with another chemical seems a much more practical solution and Calera is doing that, making cement (and turning that into concrete and the concrete into buildings) which is at least a move in a positive direction. However, algae will cheerfully "eat" pretty much all the CO² you will give it, and the resulting substance has all kinds of stored chemical energy, as lipids, as carbohydrates, as proteins, all of which have value as feedstock for other processes.
Unfortunately putting algae down an old mineshaft is not a practical solution because even if you dried it first, the organic material will rot eventually, thus releasing both methane and CO² so it's not a solution by itself. Squeeze the oil out (by some means, not necessarily "squeezing" as such), ferment the mash to alcohol and distill it, take the "distillers' mash that remains and extract the most valuable proteins (like alginates) from that remainder and finally make the rest into food supplements for animals or ingredients for humans' food (definitely bypassing the "food v. fuel" nonsense myth).
The main "challenge" will be to convince people that the sequestartion into algae is not just a way of allowing fossil fuel burners to continue to put fossil carbon into the atmosphere forever and ever. I has to be "cast" as a "gradual replacement" for the fossil source carbon, so that we are blending in some of the biomass as part of today's fossil fuel usage, with an aim to fully replace that fossil source gradually.
The good news is that although such a strategy seems to defeat the economics of multiple processes to remove multiple resources from the algae, the algae will grow so prolifically that doubling in biomass once a day (as thousands of algae species already do under good conditions of adequate light, water and CO²) it only takes 90 days, starting from ONE KILO of ALGAE to multiply itself into a theoretically impossible amount of 500 billion times the mass of the entire planet earth. Yes, really, believe it or not, less than 90 days of duplicating it's biomass would be more algae than you could possibly have on earth, which could more than replace all the other fuel sources on Earth

To go after ambient CO2 floating freely around us, bubbling air from a given depth of lime-water would capture the CO2 & particulates. Service by removing the precipitate and refill the replenishment system.

Within the algae/media bubbles of different sizes can be of different concentrations. The smaller the bubbles, it is a reasonable hypothesis that the concentration can go up. As size decreases to the point of remaining in suspension they should act as CO2 storage within the water to feed the algae and enhance growth.

Really it is good idea.but I want to know what is the difference between natural carbon dioxide and synthetic carbon dioxide if we used for algae?

Like Mr.Robert's pointed out below, industries need to widen their horizon about algae as a very potential source of CO2 capture. Its still a fairly new idea and industries seem to be very tentative about investing on it.

To be the most carbon negative possible, set up to produce algae not for energy demand but for CO2 supply. What press-cake can't be sold locally for animal feed etc. should be pelletized, packaged and sent back into the coal mine fro, where the carbon came. This way, CO2 is consumed, energy is cheap, and carbon by the ton goes back into the ground.

Have a nice day. :)

If we want to go beyond "carbon neutral" there are not too many options out there, but one possibly lucrative option is pyrolysis to create biochar. Anytime that large amounts of biomass to be processed in one place, and especially where a heat source is required for processing the feedstocks, biochar is probably a good option.
Only the "byproducts" of algae processing would need to be used for this process (one can continue to make biooil or alcohols) and the biochar production process may even result in the creation of additional bio-oils (if using fast pyrolysis). Farmed algae and marine biomass [harvested algae blooms] should work for biochar production once dried and would of course take stress off of land and forests. It could even become a multi-gigaton/year 'wedge' if the biochar is sequestered in soil. One might even be able to use Hydrothermal Carbonization to make biochar from wet biomass, although the long-term recalcitrance in soils will be shorter.

Dear Narsi
Thank you for posing these questions and for your ongoing efforts at Oilgae to advance discussion on the future of energy. I hope 2011 will be a big year for algae biofuel and for Oilgae.

As I have discussed here previously, I have sketched concepts for using plastic bags of fresh water at sea as the most practical large scale method for algae biofuel production. I lack the resources and contacts to test these ideas, but am happy to continue to discuss them here at Oilgae in the hope investors will contact me.

The Gorgon gas project in Western Australia will be the biggest CO2 sequestration project in the world according to http://en.wikipedia.org/wiki/Carbon_capture_and_storage_in_Australia#Gorgon_gas_field.2C_Barrow_Island

http://www.chevronaustralia.com/media/mediastatements.aspx?NewsItem=550ddd98-7280-4657-a473-7fdf83f16296 says “Once injection operations are at full capacity in 2015, the Gorgon Carbon Dioxide Injection Project plans to inject between 3.4 and 4 million tonnes of carbon dioxide per year”. I wrote to Chevron to ask them to consider my ideas on ocean based algae sequestration, but they were not interested. To get a very rough ballpark estimate, if this quantity of CO2 could be converted to biofuel via algae it would be worth about $4 billion per year, Instead, due to their lack of imagination, Chevron will bury it in the ground. Talk about not using their talents.