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PROPAGATION OF ALGAE BY USE OF COVERED PONDS
BY James E. Miller
All material on this wikiwebsite is licensed for use under the GNU Free Documentation licenses. For the full text of the license, see Text of the GNU Free Documentation License.
1. Abstract
As an alternative to the more costly photobioreactor approach advocated by other algae producers, Algable has designed a covered pond system. Basically each pond is 10' wide and 500' long. They are covered with plastic, cellular panels, one inch by four foot by 17.5 feet. These panels are curved and thus self-supporting and are joined by an aluminum square tube spline. Using the glycerol byproduct, we create our own anti-freeze which is heated during the day by the Sun on the panels and then pumped into a thermal energy flywheel – a large insulated cistern. The hot liquid is then pumped through a system of pipes glued to upper surface of the pond liner on the bottom of the pond. The reverse is also true. The anti-freeze can be colored to absorb excessive sunlight and pumped into the thermal energy flywheel. At night, this hot fluid is returned to the cells which then act as radiators to cool the liquid. By keeping the temperature at or about 72 degrees F. we can have year around production. Chlorella tolerate 35 to 85 degrees. There is a great gap in the processing of algae, namely the opening of the cell, spilling of the cytoplasm and the extraction of the lipids. AlgalOilDiesel has filled that gap.
2. Location
There are two main options to explore for the location of the ponds; both require nearly flat ground for the ponds.
3. Covers
Relatively low cost polycarbonate crystal panels i can be obtained in China and elsewhere which are extruded with .98�cells running the length of the panel. These cells at their distal end are capped with a plate through which there is drilled a hole which is treaded; a fitting is inserted, to which a small tube is attached. This tube runs to a header which in turn runs to a thermal energy flywheel. The covers are curved on a 25 to 30 foot radius and joined laterally with a hollow aluminum tube which has the same curve as the panel and nests in a cavity along the lateral edges. The distal end of the panels are seated in a foam or rubber gasket to create a seal against a concrete curb. The panels are self-supporting and are held in place by the spline which is also anchored to the curb. The panels are strong enough to withstand wind and snow loads. Catchments can be planned for the lower, distal ends so as to conserve rain water for crop use. The plastic will have a high resistance to UV light, and will have a useful life of about twenty years or more. A multi-layered Lexan system would most likely have a longer life than polycarbonate crystal.
4. Panel operation
The panels operate in two main modes.
The ponds are trapezoidal in cross section, about ten feet wide at the top and about five feet deep with a free board of about a foot. The would be about 500 feet long, with adjustments for legal lot lines and topography. Ideally, the flow of the algae is between ten and fourteen days. The excavated materials would be used to build the banks on either side, thus allowing for removed materials to form a part of the pond base. Sheets of foam about 2” thick would line the dirt over which a 40 to 60 mil pond cover would be laid, extending over the top of each side bank up to the concrete curb. End walls with doors would seal against the covers and the concrete curb across the ends.
6. Piping
Three sets of pipes serve the ponds. One set will convey water from the foot (harvest end) to the head of the pond. This pipe will also be used to fill the pond and for make-up water. A second set of pipes will run between the thermal energy flywheel and the pipes which are laid along the bottom of the pond on top of the pond liner. A third set of pipes, which are perforated, run parallel to the heating pipes and carry compressed air and/or CO2 when available. This latter set of pipes sparge the cells and by such turbulation, randomally and uniformly expose all cells to the sunlight. Caking of algae along the bottom and sides of the pond liners will not significantly hinder the sunlight availability to the mass of cells, unlike the photobioractors of the tube or bag kind.
7. Nutrient
A wide variety of nutrients are available for growing algae. The basic needs are carbon, nitrogen, oxygen, hydrogen and trace elements. Carbon can be supplied by the CO2 in the air. Algae can consume thirteen times the atmospheric CO2. By supplying extra C02, the increase in yield ought to be worth the effort, especially if by doing so, carbon credits can be earned and sold or tax credits obtained. Nutrients would best be fed as “tea” made from hydrolyzing the nutrient base and drawing off the enriched water. The nutrient bases would include fish parts, offal from slaughter operations, cytoplasm left from the algal oil extraction process, and similar sources.
8. Harvest
The harvest mechanics are first described in this author's paper found at: http://montanasynergy.wetpaint.com/page/BUSINESS+PLAN+FOR+SPIRULINA+CULTURE+AND+PRODUCTION. A rotating cylindar spans the width of the pond at the distal (foot) end. It is perforated stainless steel over which a mesh bag is drawn. This bag is designed so that the smaller daughter cells (recently divided “parent” cells) pass the mesh. As the drum slowly rotates, water is pumped from inside the drum, thus pulling the cells against the mesh. As they coat the mesh, they rise to the top of the drum, they are suctioned-up by a combination of a screed and the vacuum orifice. The daughter cells are returned to the head of the pond as inoculants to further propagation. The “parent” or mature cells, along with some daughter cells, are then pumped to the algal oil extraction plant. There the parent and daughter cells are separated and the daughter cells returned to the head of the pond.
9. Sanitation
Good sanitary practices are essential to maintaining a high yield. Contamination is a constant threat. The design deals with this threat by so constructing the pond system so that it is “closed” to to the outside by appropriate seals. These seals also furnish protection against thermal loss (or gain). Continuous monitoring of the water quality and the population of micro-organisms in the pond water is necessary to prevent growth of rotafers which eat algae or an attacks by virus which “hitch-hike” on the DNA of algae.
10. Economic considerations
In addition to the physical life of the pond system, consideration should be given to the probability of economic obsolescence There are presently studies being conducted at the university level for the direct conversion of vegetable oil into biodiesel and glycerol without use of alcohols or catalyzation. Early prototype experiments are using alcohol and in place of KOH, are using enzymes. While this process would adversely affect the value of the biodiesel plant, it would enhance the value of the pond and algal oil extraction process. In addition, the cell walls of Chlorella have value in the health food and supplement industry. Even if this market were to dissolve, the cell walls would still have value for fermentation into ethanol and for animal feed, if not for “mock” food amendments for human consumption. Since there will always be a likely source of waste vegetable oils from cooking operations and oils from rendered animal fats, the biodiesel plant will likely have a long life, notwithstanding enzymatic catalyzation. In addition to growing algae, there are several other sources of high quality oils not relating to the food supply such as oils from cotton seed, palm nuts, Jatropha nuts and nuts from the Paradise Tree.
The “agroforesty” approach to growing oils deserves serious study and funding of pilot projects. Nuts are not only rich in vegetable oils, but are also rich in proteins and Omega III oils. The byproducts of nut, namely the husk and shells, are valued for their carbon content, such activated charcoal made from nut shells. The nut meal has high value for animal consumption. As mentioned in the abstract, there is a persistent and nearly universal lack of good science and engineering in the algal oil industry, allowing for the economical extraction of lipids from the algae. Algable has derived nearly off-the-shelf solutions to this process [thus avoiding the “black magic” approach to science and engineering].
Simply described, we put the wet algae mass in a pressure vessel, add heat and pressure, then quickly drop the pressure and heat. The cells open up like a flower, with the cell walls intact and spill the cytoplasm. We can then separate the cell walls from the liquid and then separate the oils from the rest of the mostly water of the cytoplasm. This process is well understood and there are several companies in competition for the manufacture and sale of the thermal expansion devices and separators. We have incorporated such devices in the algal oil extraction plant.
Contact information:
James E. Miller 530 NW 13th St., Corvallis, OR 97330, USA
jimmiller@algable.com Skype: jimmiller5417 Cell: 541-971-0403
URL for this article:http://algaloildiesel.wetpaint.com/page/PROPAGATION+OF+ALGAE+BY+USE+OF+COVERED+PONDS
All material on this wikiwebsite is licensed for use under the GNU Free Documentation licenses. For the full text of the license, see Text of the GNU Free Documentation License.
1. Abstract
As an alternative to the more costly photobioreactor approach advocated by other algae producers, Algable has designed a covered pond system. Basically each pond is 10' wide and 500' long. They are covered with plastic, cellular panels, one inch by four foot by 17.5 feet. These panels are curved and thus self-supporting and are joined by an aluminum square tube spline. Using the glycerol byproduct, we create our own anti-freeze which is heated during the day by the Sun on the panels and then pumped into a thermal energy flywheel – a large insulated cistern. The hot liquid is then pumped through a system of pipes glued to upper surface of the pond liner on the bottom of the pond. The reverse is also true. The anti-freeze can be colored to absorb excessive sunlight and pumped into the thermal energy flywheel. At night, this hot fluid is returned to the cells which then act as radiators to cool the liquid. By keeping the temperature at or about 72 degrees F. we can have year around production. Chlorella tolerate 35 to 85 degrees. There is a great gap in the processing of algae, namely the opening of the cell, spilling of the cytoplasm and the extraction of the lipids. AlgalOilDiesel has filled that gap.
2. Location
There are two main options to explore for the location of the ponds; both require nearly flat ground for the ponds.
- The first option is to locate the ponds on soil which cannot support reasonable yields of crops, and which are relatively free of rock. This approach does not invade good crop lands which remain available for food and feed.
- The second option is to locate the ponds on or very near fertile soils. A “waste” product of production of biodiesel is wash water (three times the volume of finished biodiesel) which contains small amounts of potassium hydroxide and other organic impurities. As such, this waste water has a beneficial use as irrigation wanter which contains some nutrient value.
- Other location considerations include the cost of the land, the quality of soil, the quality and quantity of irrigation water, the availability of geothermal water and its quality, transportation availability including road and rail infrastructure, land use and environmental regulations, other government restrictions and permissions, labor availability and costs, and regional markets for biodiesel.
3. Covers
Relatively low cost polycarbonate crystal panels i can be obtained in China and elsewhere which are extruded with .98�cells running the length of the panel. These cells at their distal end are capped with a plate through which there is drilled a hole which is treaded; a fitting is inserted, to which a small tube is attached. This tube runs to a header which in turn runs to a thermal energy flywheel. The covers are curved on a 25 to 30 foot radius and joined laterally with a hollow aluminum tube which has the same curve as the panel and nests in a cavity along the lateral edges. The distal end of the panels are seated in a foam or rubber gasket to create a seal against a concrete curb. The panels are self-supporting and are held in place by the spline which is also anchored to the curb. The panels are strong enough to withstand wind and snow loads. Catchments can be planned for the lower, distal ends so as to conserve rain water for crop use. The plastic will have a high resistance to UV light, and will have a useful life of about twenty years or more. A multi-layered Lexan system would most likely have a longer life than polycarbonate crystal.
4. Panel operation
The panels operate in two main modes.
- During the daylight hours, the panel cells are filled with a mixture of glycerol and water, the former being a byproduct of the biodiesel production. By adding a colorant of black, the fluid will absorb solar radiation. As the fluid reaches the maximum temperature, it is drawn-off and transferred to the thermal energy flywheel. The flow of hot liquid continues until the temperature in the thermal flywheel reaches a maximum for the day.
- . At night during the colder months, the fluid in the panels is drained and the cells are filled with air which provides insulation against the cold. In colder climates, the panels made of three layers of Lexan would ideally insulate the ponds so that 72 degrees F could be maintained overnight. Were supplemental heat needed, it could be supplied with geothermal water or by heating with water heaters using the biodiesel or agricultural waste as fuel.
- During the hot summer months, the dark bio-antifreeze would absorb heat, be transferred to the thermal energy flywheel and then during the cold nights, recirculated through the panels which act as radiators. Additional cooling could be devised, using a local river or lake as a heat sink or deep bores in the earth.
The ponds are trapezoidal in cross section, about ten feet wide at the top and about five feet deep with a free board of about a foot. The would be about 500 feet long, with adjustments for legal lot lines and topography. Ideally, the flow of the algae is between ten and fourteen days. The excavated materials would be used to build the banks on either side, thus allowing for removed materials to form a part of the pond base. Sheets of foam about 2” thick would line the dirt over which a 40 to 60 mil pond cover would be laid, extending over the top of each side bank up to the concrete curb. End walls with doors would seal against the covers and the concrete curb across the ends.
6. Piping
Three sets of pipes serve the ponds. One set will convey water from the foot (harvest end) to the head of the pond. This pipe will also be used to fill the pond and for make-up water. A second set of pipes will run between the thermal energy flywheel and the pipes which are laid along the bottom of the pond on top of the pond liner. A third set of pipes, which are perforated, run parallel to the heating pipes and carry compressed air and/or CO2 when available. This latter set of pipes sparge the cells and by such turbulation, randomally and uniformly expose all cells to the sunlight. Caking of algae along the bottom and sides of the pond liners will not significantly hinder the sunlight availability to the mass of cells, unlike the photobioractors of the tube or bag kind.
7. Nutrient
A wide variety of nutrients are available for growing algae. The basic needs are carbon, nitrogen, oxygen, hydrogen and trace elements. Carbon can be supplied by the CO2 in the air. Algae can consume thirteen times the atmospheric CO2. By supplying extra C02, the increase in yield ought to be worth the effort, especially if by doing so, carbon credits can be earned and sold or tax credits obtained. Nutrients would best be fed as “tea” made from hydrolyzing the nutrient base and drawing off the enriched water. The nutrient bases would include fish parts, offal from slaughter operations, cytoplasm left from the algal oil extraction process, and similar sources.
8. Harvest
The harvest mechanics are first described in this author's paper found at: http://montanasynergy.wetpaint.com/page/BUSINESS+PLAN+FOR+SPIRULINA+CULTURE+AND+PRODUCTION. A rotating cylindar spans the width of the pond at the distal (foot) end. It is perforated stainless steel over which a mesh bag is drawn. This bag is designed so that the smaller daughter cells (recently divided “parent” cells) pass the mesh. As the drum slowly rotates, water is pumped from inside the drum, thus pulling the cells against the mesh. As they coat the mesh, they rise to the top of the drum, they are suctioned-up by a combination of a screed and the vacuum orifice. The daughter cells are returned to the head of the pond as inoculants to further propagation. The “parent” or mature cells, along with some daughter cells, are then pumped to the algal oil extraction plant. There the parent and daughter cells are separated and the daughter cells returned to the head of the pond.
9. Sanitation
Good sanitary practices are essential to maintaining a high yield. Contamination is a constant threat. The design deals with this threat by so constructing the pond system so that it is “closed” to to the outside by appropriate seals. These seals also furnish protection against thermal loss (or gain). Continuous monitoring of the water quality and the population of micro-organisms in the pond water is necessary to prevent growth of rotafers which eat algae or an attacks by virus which “hitch-hike” on the DNA of algae.
10. Economic considerations
In addition to the physical life of the pond system, consideration should be given to the probability of economic obsolescence There are presently studies being conducted at the university level for the direct conversion of vegetable oil into biodiesel and glycerol without use of alcohols or catalyzation. Early prototype experiments are using alcohol and in place of KOH, are using enzymes. While this process would adversely affect the value of the biodiesel plant, it would enhance the value of the pond and algal oil extraction process. In addition, the cell walls of Chlorella have value in the health food and supplement industry. Even if this market were to dissolve, the cell walls would still have value for fermentation into ethanol and for animal feed, if not for “mock” food amendments for human consumption. Since there will always be a likely source of waste vegetable oils from cooking operations and oils from rendered animal fats, the biodiesel plant will likely have a long life, notwithstanding enzymatic catalyzation. In addition to growing algae, there are several other sources of high quality oils not relating to the food supply such as oils from cotton seed, palm nuts, Jatropha nuts and nuts from the Paradise Tree.
The “agroforesty” approach to growing oils deserves serious study and funding of pilot projects. Nuts are not only rich in vegetable oils, but are also rich in proteins and Omega III oils. The byproducts of nut, namely the husk and shells, are valued for their carbon content, such activated charcoal made from nut shells. The nut meal has high value for animal consumption. As mentioned in the abstract, there is a persistent and nearly universal lack of good science and engineering in the algal oil industry, allowing for the economical extraction of lipids from the algae. Algable has derived nearly off-the-shelf solutions to this process [thus avoiding the “black magic” approach to science and engineering].
Simply described, we put the wet algae mass in a pressure vessel, add heat and pressure, then quickly drop the pressure and heat. The cells open up like a flower, with the cell walls intact and spill the cytoplasm. We can then separate the cell walls from the liquid and then separate the oils from the rest of the mostly water of the cytoplasm. This process is well understood and there are several companies in competition for the manufacture and sale of the thermal expansion devices and separators. We have incorporated such devices in the algal oil extraction plant.
Contact information:
James E. Miller 530 NW 13th St., Corvallis, OR 97330, USA
jimmiller@algable.com Skype: jimmiller5417 Cell: 541-971-0403
URL for this article:http://algaloildiesel.wetpaint.com/page/PROPAGATION+OF+ALGAE+BY+USE+OF+COVERED+PONDS
i
An alternative to the polycarbonate crystals is the use of Lexan panels. These panels are produced by a subsidiary of GE and can be customized into one, two or three layers, thus greatly improving the structural values and providing additional thermal insulation.
An alternative to the polycarbonate crystals is the use of Lexan panels. These panels are produced by a subsidiary of GE and can be customized into one, two or three layers, thus greatly improving the structural values and providing additional thermal insulation.
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