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Blogs under tag Bioreactor

Scaling Up. Posted by Gopinelli on Mon May 23 2011 02:38:21 PM 6

This is part of an upcoming series of blogs titled ‘Bottlenecks, Trafficbocks and Deadends’ intended to address Algae Commercialization barriers.


Please check out for my introductory post at:   http://www.oilgae.com/club/users/Gopinelli/blogs/1207


 


For an algae system, scaling up is the most important and complex commercialization barrier. There are lot of issues to be addressed for successful scale up of a bioreactor system.


In nature, open ponds are capable to provide proper light exposure to dense algae colonies at 10-15 cm depth. Such a culture usually yield 2-3 g/liter dry biomass. Thus, an open pond can contain upto 600 m3 media per acre. In raceway ponds, media volume is usually around 400 M3/acre. A bioreactor should considerably improve media holding capacity in order to justify high equipment cost. But, media capacity per acre of those bioreactors available today are not known.


Simply put, scaling up of a bioreactor means impropving both reactor volume and light penetration. Improving volume is no big deal. But, the problem lies in light exposure. Improving surface of light exposure by modifying shape of the container is one means to improve light exposure. Trying this usually take you to the dead ends.


You may consider a vertical tubular bioreactor because of the structural strength of the shape and that it allows light penetration from all around. But immediately you find that diameter of the tube can’t be increased beyond a limit for self shading of alge cells develop an internal dark region where the cells are unable to perform photosynthesis.


Vertivcal bioreactors deployed closely to one another shade each other. So you are forced to deploy the bioreactors spaced far apart from one another. You may consider increading height of the bireactors, But you find shading also inceasing in rproportion to increasing height, increasing the spacing of deployment. Further more, you need structural elements to support the tubes, inviting additional elements that shade the field. Finalky you end up with heavy imvestment, but no volume advantage.


 


You may consider modifying the shape in different ways. But, to your disappointment, the final outcome turns around to be the same. Now you understand the conservative nature of THE NATURE. And your only option is going back to open ponds and blogging on scaling up issues. Your fellow bloggers hail your language skills and that’s the desperate end of a “research”.


 


Let us look at the scenario in a different perspecive.


Light and shade are complementary to each other as night and day are. Shade occurs because there is light. Light causes earth shade, like  any opaque object. Sun continuously illuminates one side of the earth causing the earth shade itself on the other side. Axial revolution causes alternation of light and shade in defenite pattern with reference to a particular pint on earth’s surface, causing the day-night transition. In nature, day and night are in  perfect equilibrium in an ecosystem perspective. Life on the planet is adapted to this natural day-night transition.


Man has already manipulated natural phenomina, environmental elements, and even genetic sequences of organisms to make certain organisms work the way he wants. 


Algae cells do shade under light, And closely deployed bioreactors shade each other too. And we know, algae need light to perform photosynthesis, while they do not need light for cell division..


Now, lets look at a large volume photo bioreactor, A part of a dense algae colony contained within the reactor should be receiving enough light to perform active photosynthesis while light penetration gradually declines until formation of a totally dark intedrnal region. 


Here are my questions:


Can’t we isolate the outer illuminated region from  the inner dark region?


Cant we expose a fully grown mature colony to the dark region so that the cells will divide in dark, while simultaneously allowing a young colony to perform photosynthesis and grow in the illuminated region? 


A large volume bioreactor means more media volume per bioreactor. Isolating the inner shaded region from an outer dark region provides more flexibility to bioreactor size and thereby volume of the illuminated region.


But how can you effectively expose a part of a colony to light and another part of the colony to dark in the same bioreactor at the same time?


Like large plants, an algae colony comprises cells in various growth phases. But the colony can be synchronized to maintain cells in the colony in same metabolic state. Entire volume of the bioreactor can be effectively utilixed by exposing a young synchronized colony to the light region of the bioreactor and a mature synchronized colony to the dark period. Efficiency can further be improved by exposing the same colony alternatively to dark and light at a media flow rate regulated to match durations of dark period and light period of the cell cycle of the species.


 


Now, you are certain to encounter with the next issue. You need to deploy bioreactors spaced far apart from one another in the field to overcome mutual shading. This again lower media volume per acre.


What is the solution?


Like all green plants, algae can utilize only a very small fraction of insident light. The unused solar energy can be reflected to shaded areas using solar trackers. ***More on this at another time.


 


My patent pending bioreactor system has a much higher media volume per acre. A synchronized algae colony is exposed to alternate light and dark regimens. These large volume bioreactors are deployed closely to one another and sun light tracked to shaded areas using proprietary solar trackers. Depending on the cell cycle duration of the species, a daily harvest of 2,500 cubic meter to 10,000 cubic meter media per acre per day.


 


** Look out for my next blog post on 'Cell Cycle Management'

By Clean, how clean do we mean? Posted by Gopinelli on Sun March 13 2011 07:00:29 PM 1

In one of the most destructive natural disasters of recent history, powerful tsunami waves slammed into northeastern Japan devastating dozens of cities and killing thousands. As tsunami waves settles, panic broke in, with an explosion in one of the reactors in Fukushima Nuclear power plant. Today’s headlines say thousands of nuclear evacuees wonder if they'll ever see home again. Heat is building up in yet another reactor that might explode any time. And evacuation keeps going.


 


A strong and determined Japan, from the ashes of Hiroshima and Nagasaki, has emerged as one of the strongest nations in a relatively short span of time. It might take decades to heal the wounds but the nation will recover sooner. And we, from the bottom of our hearts, wish they do.


 


Now, I think, is the right time to revisit our clean energy efforts. Nuclear energy advocates force us believe it is rather safer source of energy. Yes, it doesn’t emit as much carbon dioxide or other flue gases as conventional energy sources do. It only explodes. Chernobyl is still live in our memories.


 


Those who are to ‘clean’ coal and other fossils offer us geological and ocean sequestration of carbon dioxide. Yes, it is possible to pump carbon dioxide into geological and ocean formations and believe it stays there for ever or at least for a thousand years.


 


Let’s forget the economics of nuclear power or carbon sequestration since technologies might emerge to make them economic.


 


But are they solutions? Will carbon sequestration and nuclear plants withstand such destructive earth quakes or other natural disasters?  or are we going to dig the graves for future generation?


 


Last three days again remind us of a politics lead by capital interests.


 


Today, our clean energy efforts are focused on various alternative and renewable energy sources and also energy efficiency, Billions of research dollars are flowing into these researches.


But, are we in the right direction? I strongly suspect.


 


Out of all alternative fuel sources, algae is the most applauded one. But, what is the state of research in this domain? Is there something that draws back? The tragedy began with Aquatic Species Program. Once algae was identified as a potential source of alternative liquid fuel, the project was starved of funds. Finally, the project was rolled out, though they term it ‘close out’. Since then, what happened to the research? If you compare algae research with researches in other areas of science, you will see that algae research is quite a low profile one. a vehicle designed by man more than 3 decades is still exploring deep space and sending signals to control stations on earth. Why do we cry for scaling up of bioreactors and shading of algae cells in the second decade of 21st century? Don’t we have enough geniuses to sort out such simple issues?


For electricity generation, we have many clean technologies available. But, none has potential as a total replacement to fossils. Bur we do not care much for what keeps us on earth or what keeps the earth in its relative position to other celestial objects. I am talking about gravity- the omnipresent form of force. You may read tons of information on gravity, but you will not understand what is gravity. Physicists say, it is not energy- it is only a form of force. Many people believed, and still believe, that force of gravity can be used to generate useful energy. But science objects this concept since such a situation will violate basic principles of physics. The world of science is so united on this issue that no research is promoted on free energy including gravity harness and major patent offices do not allow free energy and perpetual motion claims. But thousands of enthusiasts continue researching it and few claim success. Many believe such technologies are suppressed or prohibited, while some others suspect existence of a ‘free energy conspiracy’.


 


I have two projects, one on algae commercialization and one on gravity power harness. I have pending US patents on both. But I am sure I have miles to go getting the claims on gravity harness allowed.