Growing Algae in open pond systems
Algae can be grown in an open pond area such as ponds, lagoons, or lakes. An example of an open pond is a circular raceway pond or tank. The advantage of an open pond system is that it is much cheaper. The disadvantage is that maintaining the proper conditions for algae growth is much harder. There will be other organisms that will compete with the algae. Algae biomass yield in an open pond is not as good as other methods. There are lots of variables and conditions for algae growth that will be very hard to control. (oilgae)
Growing Algae in closed pond systems
Algae can be grown in a closed pond system using a greenhouse that will make decrease the variables needed to control for optimal growth. This will cost more than the open pond systems, but a lot less than bioreactors. More conditions will be able to be controlled. The level of Carbon dioxide used to feed the algae can be controlled and increased and so there will be more algae growth. The growing season can also be extended and the algae can be grown yearly. (oilgae)
Growing Algae in photo-bioreactor
Algae can be grown using photo-bioreactors: a bioreactor that has some sort of a light source. The advantages of these bioreactors are that a lot more variables can be controlled. The growing season can be extended and because the bioreactors are transparent, just about all the algae can be grown because there are more algae surface area exposed to the light source. The disadvantage is that these bioreactors cause a lot more than both the open pond and the closed pond systems. (oilgae)
Growing Algae in Desert
Algae can be grown in saltwater ponds in the desert or in photo-bioreactors. This will solve our problem of agricultural land use. The challenges would be keeping the temperature around 70 degrees Fahrenheit, adequate water, and etc. The weather is the same throughout the year. (oilgae)
Growing Algae in Sewage Treatment Plant
Algae can be grown in sewage plants in ponds. Algae can extract the nutrients from the waste and the water and the pollutants in the atmosphere. AquaFlow in New Zealand has experimented with this method. (oilgae)
Growing Algae in Marine environment
Growing Algae for CO2 Sequestration
Growing algae Near Power plant
Growing algae Near Cement Plant
Harvesting of Macro Algae
Macro Algae are easier to harvest then micro-algae because they are much larger. Macro algae grow in water and float in it and on solid substrates such as wood, textiles, and etc. A net can be used to harvest macro algae. Another method is using a mower machine with a vacuum pump to collect the algae. (oilgae)
Harvesting of Micro Algae
There are lots of methods for harvesting micro algae such as: filtration, centrifugation, flotation, and flocculation. Filtration can be accomplished by using a concentrated suction pump to collect the micro algae. Clogging can occur when the cells pack together, but a reverse suction pump can solve the problem. Centrifugation can be achieved through using a centrifuge. The centrifuge will make the micro algae fall and rest at the bottom of the container. However, centrifugation is very expensive. Flotation can be completed through a simple method of causing the algae to rise to the surface. Flocculation is another method in harvesting algae in which chemicals are used to separate the algae and makes the algae form lumps. It is very costly and removing the chemicals used is hard. (oilgae)
Extraction of algal oil by Mechanical Methods
The methods for extraction of oil from algae include: expression/expeller press, mechanical crushing, and ultrasonic-assisted extraction. Mechanical crushing is the most simplistic method of extracting oil from the algae, but this method can be used with chemicals. Expression/Expeller press can be achieved through drying the algae and then using an oil press to extract the oil from it. Using ultra-sonic reactors we can send ultra-sonic waves and liquid jets to break the cell walls, which will cause the cell to dump its contents. (oilgae)
Extraction of algal oil by Chemical Methods
Algae oil can be extracted by using Chemicals such as Benzene; a carcinogen. Lots of care must be used in handling these chemicals. The methods for extraction include: Hexane Solvent Method, Soxhlet Extraction, and Supercritical fluid Extraction. All three methods share the common idea of extracting the oil from the algae using chemical solvents. (oilgae)
Strains of Algae currently being studied
These are species of algae currently being studied for mass production of oil worldwide.
Chlorophyceae (green algae)
Bacilliarophy (diatom algae)
What is the process that converts plant and vegetable oils into biodiesel? The process is known as transesterification. Scientists E. Duy and J. Patrick at the very first conducted the process in 1853. It is not new, but rather complicated. (oilgae)
As a team we decided that the best way to get information on this subject would be to go hands on and actually experiment with trying to make algae bio-diesel ourselves. We went down to our local creek and harvested common algae, talked to local biologists, and physically tested many different ways we could possibly make an algae based bio-diesel. This is our week by week progress of our experiment, what happened, and what conclusions we came to based on the experiments.
Week One: (June 16-20)- As this was the first week, not much experimenting happened. We mostly studied and figured out what we wanted to test. On Wednesday (June 18th) we ordered a test tube of Botryococcus braunii algae to grow that we would use for experimenting . We had to order this specific species because some species of algae do not produce the oil we need.
Week Two: (June 23-27)- This week we started collecting algae from our local creek to test a pressing method for squeezing out any oils, then collecting them to check flamablility. Using a retrofitted 5-Ton shop press with a home made algae squeezing device I was able to produce a small amount of oil mixed with creek water. Even more dissapointing was the flamability test, when the only thing that burned was our supervisor's hand from holding the match for too long. We figured that the oil was not flamable due to its high water content. Last, the algae culture we ordered arrived and was set up to grow on Wednesday (June 25th)
Week Three: (June 30- July 4)- The halfway mark of our time shows that the algae has started growing and we will leave it to grow for as long as we have. One thing this has taught us is that algae grows fairly slowly. You can see the progress everyday, but the progress is very little. We went down to the local creek and gathered more algae. One thing for sure is that algae is not hard to get. It took about a half hour for two people to collect two pounds. That's saying a lot considering the weight of algae. Last, we set some algae harvested from the local creek on the roof to dry until next week.
Week Four: (July 7-11)- Week four brought not much results. With the algae still slowly growing, we will wait until we have enough to start testing. We pressed last weeks batch into oil rich tablets since there was not enough oil produced to have a liquid. We tried burning those tablets but they burned about as well as green grass. They just lay there smoldering and burning a bit. The algae is growing but we are all losing faith in the pressing oil out of algae technique.