Posted by Stella
Excellent paper, more detailed than some of the review papers I've read, about why algae is so suitable to biofuel production. May be worth using for background information.
Aquatic phototrophs: efficient alternatives to land based crops for biofuel
I have other links I'll post when I get back to Aberdeen.
Sunday, 21 November 2010
Saturday, 20 November 2010
More papers
Posted by Christopher
These may also be worth a look, but I'm at home just now and can't see them. I'll look at these when I'm in uni, however feel free to peruse them yourselves.
Liquid fuel (oil) from halophilic algae: A renewable source of non-polluting energy
CO2 fixation and oil production using micro-algae
A green light for engineered algae: redirecting metabolism to fuel a biotechnology revolution
These may also be worth a look, but I'm at home just now and can't see them. I'll look at these when I'm in uni, however feel free to peruse them yourselves.
Liquid fuel (oil) from halophilic algae: A renewable source of non-polluting energy
CO2 fixation and oil production using micro-algae
A green light for engineered algae: redirecting metabolism to fuel a biotechnology revolution
Algae Oils
Posted by Christopher
This paper's worth a read:
http://www.scipub.org/fulltext/ajbb/ajbb43250-254.pdf
I've copied over some parts of the paper so you can get an overview.
"Microalgae can provide several different types of
renewable biofuels. These include methane produced
by anaerobic digestion of the algal biomass[6] biodiesel
derived from microalgal oil[11,12,13] and
photobiologically produced biohydrogen[14,15]."
Paper details methods of extraction, and even an efficiency over two species of fresh weight -> dry weight -> mass of oil extracted!
Table from paper:
"
Fresh weight Dry Extracted weight extracted oil Biomass
Spirogyra sp. 24.5 (g) 8.09 (g) 1.8 (g) 3.5 (g)
33.0 (%) 7.3 (%) 43.3 (%)
Oedogonium sp. 32.4 (g) 11.3 (g) 3.0 (g) 3.8 (g)
34.8 (%) 9.2 (%) 33.6 (%)
"
This paper's worth a read:
http://www.scipub.org/fulltext/ajbb/ajbb43250-254.pdf
I've copied over some parts of the paper so you can get an overview.
"Microalgae can provide several different types of
renewable biofuels. These include methane produced
by anaerobic digestion of the algal biomass[6] biodiesel
derived from microalgal oil[11,12,13] and
photobiologically produced biohydrogen[14,15]."
Paper details methods of extraction, and even an efficiency over two species of fresh weight -> dry weight -> mass of oil extracted!
Table from paper:
"
Fresh weight Dry Extracted weight extracted oil Biomass
Spirogyra sp. 24.5 (g) 8.09 (g) 1.8 (g) 3.5 (g)
33.0 (%) 7.3 (%) 43.3 (%)
Oedogonium sp. 32.4 (g) 11.3 (g) 3.0 (g) 3.8 (g)
34.8 (%) 9.2 (%) 33.6 (%)
"
Pyrolysis and Gasification
Posted by Christopher
Investigation into pyrolysis and gasification as means of extracting viable fuels from organic matter suspended due to an absence of available data quantifying production efficiency. I surmise the most likely reason for this will be that actual efficiency will depend on commercially protected variations to the base process. While it may be possible to obtain values, it is not practical within the time constraints upon this study.
As noted in minutes to recent meeting, I will be turning my attention towards chemical comparisons to other biofuels, specifically energy density of our product and the implications of this towards it's implementation.
Investigation into pyrolysis and gasification as means of extracting viable fuels from organic matter suspended due to an absence of available data quantifying production efficiency. I surmise the most likely reason for this will be that actual efficiency will depend on commercially protected variations to the base process. While it may be possible to obtain values, it is not practical within the time constraints upon this study.
As noted in minutes to recent meeting, I will be turning my attention towards chemical comparisons to other biofuels, specifically energy density of our product and the implications of this towards it's implementation.
Friday, 19 November 2010
Some important figures for Algae
Posted by Rachel
There seems to be a lot of conflicting information about some of the figures related to algae, especially when it comes to determining the yield of oil by the plant. The textbook that I showed the group on Wednesday (Biological Energy Resources; M Slesser, C Lewis; 1980) gives a short-term high yield of 24g/m^2 which seems distinctly average when compared with yields from other crops. However, this is by now an old-ish book so looking at more recent statistics on the internet I have managed to come up with the following stats (hopefully I have covered most of what we discussed on Wednesday). First of all, it must be remembered that different species of algae produce different amounts of oil. Some species (such as Diatoms) can produce 50% oil, whereas some species will produce a little less.
Crop lifecycle: Micro-algae are the fastest growing photosynthesizing organisms. They can complete an entire growing cycle every few days.
Yield:
A note about species of algae to consider:
Diatoms appear to be one of the more promising species to consider in the production of energy resources although research into them is still ongoing. The link above has some more information on them towards the bottom of the page if anyone is interested.
There seems to be a lot of conflicting information about some of the figures related to algae, especially when it comes to determining the yield of oil by the plant. The textbook that I showed the group on Wednesday (Biological Energy Resources; M Slesser, C Lewis; 1980) gives a short-term high yield of 24g/m^2 which seems distinctly average when compared with yields from other crops. However, this is by now an old-ish book so looking at more recent statistics on the internet I have managed to come up with the following stats (hopefully I have covered most of what we discussed on Wednesday). First of all, it must be remembered that different species of algae produce different amounts of oil. Some species (such as Diatoms) can produce 50% oil, whereas some species will produce a little less.
Crop lifecycle: Micro-algae are the fastest growing photosynthesizing organisms. They can complete an entire growing cycle every few days.
Yield:
- At an assumed recovery rate of 30% of the weight of algae, 45.6 tonnes of oil/hectare/year can be produced from Diatom algae.
- Under optimum growing conditions micro-algae will produce up to 4 lbs./sq. ft./year or 15,000 gallons of oil/acre/year.
- Algae yield: 100 tonnes/ha.
- 2.2 tonnes carbon dioxide needed / 1 tonnes algae
- Water needed 4m3/m2. Most of the water is lost due to evaporation, some is consumed by the algae, and some is lost in the harvesting of the algae.
- A 500 MW coal fired power station produces 3.67x106 tonnes of carbon dioxide
- 3.5 barrels of biodiesel per tonne algae produced
- 6 MJ methane per tonne algae generated
- Energy density of LNG is 15.2 kWh/kg and density is 448 kg/m3
A note about species of algae to consider:
Diatoms appear to be one of the more promising species to consider in the production of energy resources although research into them is still ongoing. The link above has some more information on them towards the bottom of the page if anyone is interested.
Minutes for meeting 4
Posted by Stella
Friday 19 November
Friday 19 November
Present: Stella Kin, Louise Anton, Bryan McCulloch, Christopher Sanderson
Next meeting: Wednesday 24 November
1. Presentation of research so far
Louise detailed her research on the environmental impact of algae. Algae may not be as green as it seems, as the manufacturing processes are petroleum based. However this can be countered by locating a bioreactor next to waste processors and using the waste products to power the reactor.
Bryan presented his research on genetically-modified algae. Yields are dependent on algae type, but one paper shows an increased algae yield of ten times using GM. More research is needed.
Chris presented his research on 4th generation. 4th gen information is limited to what is behind commercial walls and how much is available to the public. There are also wider concerns about genetically modifying micro-organisims and the social implications.
Stella presented research into Craig Venter's oil-secreting algae, effectively cutting out the mechanical process. Again, there appear to be no papers published so far, so the information available is limited to press released from Synthetic Genomics. Realistically we may have to go down traditional routes, but we should consider the GM route.
2. Allocation of tasks
Environmental / Societal implications - Louise
Potential problems including GM - Bryan
Technical (mechanical, GM, farming/bioreactors) - Stella
Comparisons with other biofuels - Chris
Introduction and background - Rachel
3. Decision on which biofuel
Algae was decided on unanimously.
4. Weblog
Stella requested that everyone post their links on the weblog as evidence of research, with reasons why it is useful. It was agreed that more effort should be made.
5. Any other business
Louise suggested we each write a short summary on our research by Wednesday to share with the team.
Stella suggested meeting on Mondays in addition to the Wednesday and Friday meetings.
Louise detailed her research on the environmental impact of algae. Algae may not be as green as it seems, as the manufacturing processes are petroleum based. However this can be countered by locating a bioreactor next to waste processors and using the waste products to power the reactor.
Bryan presented his research on genetically-modified algae. Yields are dependent on algae type, but one paper shows an increased algae yield of ten times using GM. More research is needed.
Chris presented his research on 4th generation. 4th gen information is limited to what is behind commercial walls and how much is available to the public. There are also wider concerns about genetically modifying micro-organisims and the social implications.
Stella presented research into Craig Venter's oil-secreting algae, effectively cutting out the mechanical process. Again, there appear to be no papers published so far, so the information available is limited to press released from Synthetic Genomics. Realistically we may have to go down traditional routes, but we should consider the GM route.
2. Allocation of tasks
Environmental / Societal implications - Louise
Potential problems including GM - Bryan
Technical (mechanical, GM, farming/bioreactors) - Stella
Comparisons with other biofuels - Chris
Introduction and background - Rachel
3. Decision on which biofuel
Algae was decided on unanimously.
4. Weblog
Stella requested that everyone post their links on the weblog as evidence of research, with reasons why it is useful. It was agreed that more effort should be made.
5. Any other business
Louise suggested we each write a short summary on our research by Wednesday to share with the team.
Stella suggested meeting on Mondays in addition to the Wednesday and Friday meetings.
Agenda for Meeting 4
Posted by Stella Kin
19 November 2010
1. Discussion of research so far
2. Final decision on choice of biofuel
3. Allocation of tasks
5. Any other business
19 November 2010
1. Discussion of research so far
2. Final decision on choice of biofuel
3. Allocation of tasks
- Introduction - which biofuel and why
- Background info
- Technical info - physics manufacturing process
- Environmental impact
- Societal impact
- Comparison with other biofuels
- Potential problems
- Business plan
5. Any other business
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