Raw Data for Introduction

Posted by Rachel

This is the raw data that will be incorporated into the first couple of slides for the introduction/background. I have already made charts from some of the data to make it more visually interesting.

Energy consumption in Scotland (2002)

Total: 175 TWh of energy

Split into four categories of use:

1. Domestic
2. Transport - public and private
3. Industry 
4. Services

As our project primarily deals with the production of oil from algae (Oilgae if you will) and biodiesel then I have looked in more detail at the data for domestic and transport, essentially ruling out industry and services as areas which this project could have a notable effect on.

Domestic:

• Accounted for 34% of the total energy consumed in Scotland in 2002. 
• Domestic energy for heating is primarily done by gas.
• Domestic users were the largest consumers of energy in 1990, 2002 and thus we can presume 2010.

Transport:

• Accounted for 29% of consumed energy.
• Principal fuel use: oil.
• The 2001 census (takes into account 2,192,246 households) reports that 43% of households have regular access to 1 car while 22% have regular access to 2 or more cars. So we can estimate that 65% of households own at least one car, meaning that there are approximately (probably more than) 1,424,960 cars on the road in Scotland.

Approximately 1,150TWh of oil is produced in Scotland per annum - most of it is exported but almost 10% is refined in the country. The majority of oil energy products (eg. petroleum) are used for transport although some are utilised in heating.

Information from www.scotland.gov.uk


This will provide the basis of the introduction in terms of data and getting an idea for the energy demand/consumption. I will be presenting the "problem" as a small recap (obviously not in great detail as we all know what we've been doing), moving on to outline the current energy situation in Scotland using the information above and, if required, a small introduction to our solution and algae.

Script draft for algae production... not yet finished

Posted by Stella

Microalgae are one of the planet’s most promising sources of renewable biomass. They exist as unicells, colonies and long filaments, and can grow in a wide variety of conditions – from freshwater to extreme salinity. They are more efficient converters of solar energy than terrestrial plants and take carbon dioxide out of the atmosphere as they grow.

Macroalgae, or seaweeds, are also highly efficient at converting solar energy into biomass and their simple internal structure makes them a better material than land plants for complete biological degradation.

During the ... project, strains algae of characterised by high biomass and high oil yields will be selected for genetic modification. The objective is to genetically engineer micro-algae so that firstly it enhances lipid production rates by increasing the activity of the apprpriate enzyme(acetyl-CoA carboxylase (ACCase), a biotin-containing enzyme that catalyzes an early step in fatty acid biosynthesis, may be involved in the control of this lipid accumulation proces), secondly mutating and photoadapting algal strains to
improve flux tolerance by reducing chlorophyll antenna size, and thirdly secrete oil droplets into the surrounding medium. This could lead to continuous harvesting with clean separation of the oil from the algae.

The Culture Collection of Algae and Protozoa (CCAP) at the Scottish Association for Marine Science (SAMS) holds the largest algal culture collection in Europe, some 2700 strains, from which all suitable candidate strains will be screened.

The algae will be grown in closed bioreactors with light, CO2 and nutrients supplied to optimise biomass growth and oil productivity. Once a suitable genetically engineered strain has been identified, there is the potential to enter into partnership with energy compainies for further investment.

There are three key requirements for biodiesel production:

1. Sustainable production of high-oil-yielding microalgae strains

This is the critical requirement, given that there are 200,000-800,000 estimated algae strains, each with differing optimal growth conditions. Considerable research has already been invested into identifying suitable strains of algae. Those most widely utilized for current commercial applications belong to the genera Chlamydomonas, Chlorella, Haematococcus, and Dunaliella, with an oil content of 25-30%. Diatoms, that is brown algae, have an oil content of 60-70%. The number of potential strains may be narrowed down by applying criteria, such as:

• efficient phosynthetic capacity
• high lipid content, 
• faster growth rate, 
• possibly thermophilic, 
• survive in hydrocarbon mixture exocytosed, 
• possession of a cell membrane so that the oil may be diffused into the surrounding medium, or a mechanism through the cell wall by which oil may be secreted

 
Once a suitable strains have been identified, they can be genetically engineered so that they exocytose their oil droplets. The process is likened to milking cows.

"We do not harvest milk from cows by grinding them up and extracting the milk. Instead, we let them secrete the milk at their own pace, and selectively breed cattle and alter their environment to maximize the rate of milk secretion."

The milking of algae has been done by solvent extraction methods, e.g. dicholoromethane, that do not kill the cells, but in which they are otherwise passive. Here, we propose altering cells so that they actively secrete their oil droplets.

• The process has already been announced by Synthetic Genomics in partnership with Exxon Mobile.
• Exocytosis of beta-carotene globules has been hypothesized as the mechanism of extraction into the biocompatible hydrophobic liquid dodecane from the unicellular green alga Dunaliella
• Higher plants have oil secretion glands, and;
• diatoms already exocytose the silica contents of the silicalemma, adhesion and motility proteins, and polysaccharides, 

so the concept of secretion of oil by diatoms is not far-fetched.

In addition each algae strain will respond differently to varying temperatures, pH, light, as well as photo-oxidative and nutrient stress. These condions can be calibrated in closed photo-bioreactors

A mixture of air and CO2, is bubbled through the reactor, providing both a source of carbon and mixng the medium. The reactor is surrounded with solar-powered LEDs, so that the outer surface is illuminated with light, while the central core is shaded. Nutrients in the form of nitrogen, phosphorous, and in the case of diatoms, silicon are supplied.

The project can take advantage of the almost daily advancements in algal biotechnology by applying new discoveries to our chosen alage strains.

For example

• Projected annual algal biomass yields could be increased from 1g dry weight m-2 h-1, to 100g. by subjectiong algae to microsecond pulses of intense red light at tens to hundreds of kilohertz. Uses a combination of: ultra-efficient high-flux photovoltaics converting solar energy to electricity, and LEDs then converting electricity to pulsed nominally monochromatic red light (review paper: Spirulina platensis (cyanobacteria).
• In a two-phase cultivation process, that is, a nutrient sufficient phase to produce the inoculum followed by a nitrogen deprived phase to boost lipid synthesis, the oil production potential could be projected to be more than 90 kg per hectare per day.
• Only 3 weeks ago researchers at MSU found that when baking soda was added at a particular time in the growing cycle, it more than doubled the amount of oil produced in half the time. The discovery should have broad application. 
• Oscillating microbubbles can boost algae yields by 30 percent, using 18% less energy than standard sparging systems. (20 micrometers versus 1–3-mm diameter for sparging. Microbubbles of CO₂ dissolve faster, keep the suspension well mixed, and also help remove oxygen (which is toxic to algae). (Patented)

2. Extraction of the oil from the algae 

The conventional technique involves evaporation of the watery medium, pressing to squeeze the oil out, and centrifuging to separate the oil from the remnants. The cost is estimated to be as much as 50% of biofuel production. 

By secreting the oil directly into the medium, the extraction process can almost entirely be bypassed. With at least a boundary layer of water on the diatoms, secreted oil droplets would separate under gravity, rising to the top, forming an unstable emulsion, which should progressively separate. The oil could then be removed, very similar to the cream that rises to the top of milk.

Solvent is dichloromethane. 

3. Conversion of microalgal oil into biodiesel

The parent oil consists of triglycerides. It then undergoes transesterification, that is, it is reacted with methanol to produce methyl esters of fatty acids, that are biodiesel, and glycerol. 

Yields of methyl esters exceed 98%. The biodiesel is recovered by repeated washing with water to remove glycerol and methanol.

The hydrocarbon mixture is similar to crude petroleum, along with volatile alkane and alkene gases (C2-C5). This conversion allows the generation of a burnable fuel of very high calorific value.

Repost: of Bryan's link: Biomara

Posted by Stella Kin

Biomara

I've looked at this again and I think Bryan's right, the overview could be a good model for our proposal, so I'm reposting it for visibility.

Draft power point slides: algae oil production

Posted by Stella Kin

Draft slides for the algae production bit for the power point presentation. I'll try to think of a more creative way of presenting them.
=================================================
Why micro-microalgae?

Biomass production

• minimum of internally competitive plant functions
• fast reproductive cycles
• limited nutrient requirements
• flexible cultivation conditions

The algae biofuels are

• non-toxic
• similar to petroleum
• high yields of fuels

Environmental benefits

• fix CO2

******************************

Which algae?

• Chlamydomonas, Chlorella, Haematococcus, and Dunaliella
• Diatoms
• 60-70% oil 
• yield 30,000L (or 200 barrels) of oil h-1 per annum

******************************

What needs to be done?

• Identify diatoms and species with high lipid content
• Design of new technology to grow and harvest algae
• Genetic modification of algae to secrete oil

Conditions for growing biomass

• Light
• CO2
• Nutrient deprivation
• Microbubbles

**************************
Biodiesel production

Gasoline production?

Summary of algae research / proposal

Posted by Stella Kin

I've summarised all the algae biomass growth and oil extraction into one post. I'll condense this into power point bullet points shortly.

What I think we should conisder is putting the money into research as discussed before. Like the start up conceived by Wageningen University, we can invest in a number of areas of research including which algae types can be genetically modified to secrete oil, and what conditions of light, nutrient stress, CO2 levels, photo-bioreactor design etc will optimise oil production. Without the algae to begin with, we won't have definitive figures for yields, but but we can make rough estimates from research from different papers. There is no guarantee of success, but if the start-up is successful, we can approach (or most likely be approached by) private energy/oil companies for investment similar to the Exxon-Synthetic Genomics partnership.

Proposal for a start-up to facilitate the research of growth and oil production of microalage in a photobioreactor

Why microalgae?

Algae (as opposed to other plants) are a natural choice for maximum-yield biofuels because of: 

Biomass growth

1. They intrinsically offer the greatest flux tolerance and photosynthetic efficiency as a consequence of minimum of internally competitive plant functions,  
2. enjoy fast reproductive cycles,  
3. have limited nutrient requirements, requiring only sunlight, water, minerals and carbon dioxide, and
4.  flexible cultivation conditions 

• They can be grown under conditions which are unsuitable for conventional crop production, unlike some other first- and second-generation biofuel feedstocks.  
• They can be cultivated under difficult agro-climatic conditions and are able to produce a wide range of commercially interesting byproducts such as fats, oils, sugars and functional bioactive compounds. 
• They can readily be exposed to temporal and spectral irradiation distributions and intensities that are not encountered in nature but are optimal for bioproductivity via cleverly crafted photonic systems.
• They can be cultivated in marine water and waste water, deserts, etc, etc.

The algae biofuels produced are:

1. non-toxic, contains no sulfur, and is highly biodegradable. 
2. Bio-oil produced by photosynthetic algae and the resultant biofuel will have molecular structures that are similar to the petroleum and refined products we use today. 
3. They provide much higher yields of biomass and fuels, 10-100 times higher than comparable energy crops. Algae could yield more than 2000 gallons of fuel per acre per year of production. Approximate yields for other fuel sources are far lower:
   - Palm — 650 gallons per acre per year
   - Sugar cane — 450 gallons per acre per year
   - Corn — 250 gallons per acre per year
   - Soy — 50 gallons per acre per year

Research and potential

1. Algae used to produce biofuels are highly productive.  As a result, large quantities of algae can be grown quickly, and the process of testing different strains of algae for their fuel-making potential can proceed more rapidly than for other crops with longer life cycles. 
2. If successful, bio-oils from photosynthetic algae could be used to manufacture a full range of fuels including gasoline, diesel fuel and jet fuel that meet the same specifications as today’s products.

Environmental benefits

1. Microalgae are capable of fixing CO2 in the atmosphere, thus facilitating the reduction of increasing atmospheric CO2 levels. This provides greenhouse gas mitigation benefits.
2. Use and cleaning of wastewater 

Which algae? 
Those most widely utilized for current commercial applications belong to the genera Chlamydomonas, Chlorella, Haematococcus, and Dunaliella. 

Diatoms (brown algae), a group of silicon-rich microalgae, and prokaryotic cyanobacteria also offer substantial opportunities for metabolic engineering and biotechnology.

• Responsible for 1/5 photosynthesis on earth
• Fixes 25-30% of global CO2
• Oil content is 60-70% saturates
• Theoretical calculation - yield 30,000L (or 200 barrels) of oil h-1 per annum.
• Photo-oxidative stress and nutrient structure (N, Si) can double or triple the production of oil because of a shift in lipid metabolism from membrane lipid synthesis to storage of neutral lipid
• Could conceivably be genetically engineered so they secrete the oil they produce rather than store it, and therefore need not to be destroyed to obtain oil
• eliminates cumbersome and expensive extraction process
• construction of solar panels/angiosperm leaf to cultivate and extract algae
• diatoms secreting gasoline (instead of crude oil)

What needs to be done?

1. Identify diatoms and species with high lipid content, faster growth rate, in low cost ..., thermophilic, survive in hydrocarbon mixture exocytosed, efficient photosynthetic capacity.
2. Design of new technology to grow and harvest algae, or use current technology - bioreactors?
3. Genetic modification of algae to secrete oil, produce gasoline, change chlorophyll atennae size, etc.

The first is the kep step as there are thousands of micro-algae types and hundreds of just diatoms. Identifying an algae that fits with the criteria is relatively easy. However each algae will respond differently to varying temperatures, pH, light, as well as photo-oxidative and nutrient stress. The question is which algae in which conditions will maximuse oil yield? And can the algae be genetically modified to secerete it's oil?

Step 2: Modification of current bioreactor designs

Photobioreactor supplies light, CO2, nutrients, mixing and optimal culture density

The light in an aerated vertical column can be supplied by light redistribution plates (solar powered), LEDs (possibly solar powered) or even optical fibres

Adv: High mass transfer, good mixing with low shear stress, low energy consumption, high potentials for scalability, easy to sterilize, readily tempered, good for immobilization of algae, reduced photoinhibition and photo-oxidation
Disadv: Small illumination surface area, their construction requires sophisticated materials, shear stress to algal cultures, decrease of illumination surface area upon scale-up 

Light
One of the limiting factors is in fact light. Diatoms flourish at low light levels. Above a certain value of light intensity, a further increase in light level actually reduces the biomass growth rate (see figure) – photoinhibition – at light intensities only slightly greater than the light level at which the specific growth rate peaks.

One solution advocated is irradiating the algae with microsecond pulses of intense red light at tens to hundreds of kilohertz. Through turbulence, the algae are therefore cycled through light and dark zones at high frequency, allowing an increase in the algae's flux tolerance to light. Projected annual algal biomass yields could be increased from 1g dry weight m-2 h-1, to 100g.

Photosynthesis driven with pure red light is ∼5 times more efficient than with full-spectrum sunlight. It could involve a combination of: (a) Ultra-efficient high-flux photovoltaics converting solar energy to electricity, and (b) LEDs then converting electricity to pulsed nominally monochromatic red light

Photovoltaic-LED combination can transform solar radiation into pulsed red light at conversion efficiencies of ∼20% with commercially available components

Effect of nutrient deprivation
Under nutrient sufficient and deficient conditions, for specific strains, lipid productivity increased from 117 mg/L/day in nutrient sufficient media (with an average biomass productivity of 0.36 g/L/day and 32% lipid content) to 204 mg/L/day (with an average biomass productivity of 0.30 g/L/day and more than 60% final lipid content) in nitrogen deprived media. 

In a two-phase cultivation process (a nutrient sufficient phase to produce the inoculum followed by a nitrogen deprived phase to boost lipid synthesis) the oil production potential could be projected to be more than 90 kg per hectare per day. 

CO2
When added at a particular time in the growing cycle, baking soda more than doubled the amount of oil produced in half the time in three different types of algae. If growers can produce oil faster, they can reduce the opportunity for contamination to ruin the product. The three types of algae used in the study were not closely related, so the discovery should have broad application. (11 November 2010) 

Mixing using microbubbles
Airlift bioreactor usesing oscillating microbubbles can boost algae yields by 30 percent. It uses 18% less energy than standard sparging systems. The generator improves the performance of air-lift loop bioreactors (ALBs) by producing smaller bubbles, around 20 micrometers versus 1–3-mm diameter for sparging. Produces 30% more algae than one fed with conventionally produced bubbles. Microbubbles of CO₂ dissolve faster, keep the suspension well mixed, and also help remove oxygen (which is toxic to algae). (Patented)

Step 3: Genetic modification to secrete oil

"We do not harvest milk from cows by grinding them up and extracting the milk. Instead, we let them secrete the milk at their own pace, and selectively breed cattle and alter their environment to maximize the rate of milk secretion.266–269 We do not simultaneously attempt to maximize their rate of reproduction. Perhaps we could do the same with diatoms. The milking of algae has been done by solvent extraction methods that do not kill the cells,270,271 but in which they are otherwise passive. Here, we propose altering cells so that they actively secrete their oil droplets."

It may be possible to genetically engineer diatoms so that they exocytose their oil droplets. This could lead to continuous harvesting with clean separation of the oil from the diatoms, provided by the diatoms themselves.

Exocytosis of beta-carotene globules has been hypothesized as the mechanism of extraction into the biocompatible hydrophobic liquid dodecane from the unicellular green alga Dunaliella, perhaps accelerated from the natural exocytosis mechanism of this species by the presence of the dodecane. Higher plants have oil secretion glands, and diatoms already exocytose the silica contents of the silicalemma, adhesion and motility proteins, and polysaccharides, so the concept of secretion of oil by diatoms is not far-fetched.

Adapting the bioreactor for oil secretion
A system that is closed except for oil secretion and gas exchange may be able to conserve micronutrients, especially if little or no net growth of cells is occurring. This might solve the productivity gap by getting 10-200 times more oil, compared to oilseed crops.

With at least a boundary layer of water on the diatoms, secreted oil droplets would separate under gravity, rising to the top, forming an unstable emulsion, which should progressively separate. The oil could then be removed, very similar to the cream that rises to the top of milk.

Gasoline production?
Biodiesel refers to a vegetable oil- or animal fat-based diesel fuel consisting of long-chain alkyl (methyl, propyl or ethyl) esters. Biodiesel is typically made by chemically reacting lipids (e.g., vegetable oil, animal fat) with an alcohol. Biodiesel can be used alone, or blended with petrodiesel. However, higher levels of polyunsaturated fatty acids tend to decrease the stability of biodiesel.

The bulk of a typical gasoline consists of hydrocarbons C4-C12.

Hypothesis that some short-chain hydrocarbons are produced during diatom and dinoflagellate lifecycles. Their results suggest that ethane, ethene, propane and propene are produced during the autolysis of some phytoplankton, possibly by the oxidation of polyunsaturated lipids released into their culture medium.

In contrast, isoprene and hexane appear during phytoplankton (of which diatoms are a type) growth and are thus most likely produced either directly by the plankton or through the oxidation of exuded dissolved organic carbon. Studies predict that high concentrations of ethylene are produced in areas with high primary productivity. This is supported by observations of C2-C4 alkanes in ocean surface waters, along with isoprene (C5), also attributed to algae (mostly diatoms), and direct laboratory observation of isoprene production by diatoms.

Biodiesel production

The parent oil consists of triglycerides. It is reacted with methanol (transesterification) producing methyl esters of fatty acids, that are biodiesel, and glycerol.

Yields of methyl esters exceed 98%. The biodiesel is recovered by repeated washing with water to remove glycerol and methanol.

The hydrocarbon mixture is similar to crude petroleum, along with volatile alkane and alkene gases (C2-C5). This conversion allows the generation of a burnable fuel of very high calorific value.

Lipids in diatoms are converted to hydrocarbons:
C50H92O6   =>    CXHY           +        nCO2
    lipids               hydrocarbon          carbon dioxide

From this, it is evident that the direct extraction of diatom lipids is a more-efficient method for obtaining energy than fermentation. This can occur by having solvents such as CH2Cl2 (dichloromethane), through the direct expression of the liquid lipids, or a combination of both methods. The thermochemical liquefaction process often results in a heavy oily or tarry material that is then separated into different fractions by catalytic cracking. As with hydrocarbons derived from other forms of renewable biomass, microalgal diatom lipids can be converted to suitable gasoline and diesel fuels through transesterification.

Agenda for Meeting 7

Posted by Stella Kin

29 November 2010

1. Discussion of proposed pilot study of oil production from diatoms/ microalgae.
2. Put presentation slides together and talk through what each person is going to say.
3. Budget
4. Any other business

Edited: postponed to Tuesday 30 November
Edited: postponed to Wednesday 1 December

Effects of nutrent starvation

Posted by Stella Kin

Under nutrient sufficient and deficient conditions, for specific strains, lipid productivity increased from 117 mg/L/day in nutrient sufficient media (with an average biomass productivity of 0.36 g/L/day and 32% lipid content) to 204 mg/L/day (with an average biomass productivity of 0.30 g/L/day and more than 60% final lipid content) in nitrogen deprived media. In a two-phase cultivation process (a nutrient sufficient phase to produce the inoculum followed by a nitrogen deprived phase to boost lipid synthesis) the oil production potential could be projected to be more than 90 kg per hectare per day. 

That nitrogen deprrivation increases oil productibity is pretty well established. This is just for reference.

Reference
Oilgae

Sustainable start-up facility that looks into many aspects of scaling up alage production

Posted by Stella Kin

algaePARC

Interesting start-up company. It seems to be trying to improve alage production at all stages. We could go down this route, or we could stick to GM. I think the former is less risky, the latter will have bigger pay-offs if it's successful. Conceivably we could then pair up with an oil company for a funding injection, like Exxon and Synthetic Genomics.

They are also examining milking of Dunaliella for oil soluble beta-carotenoids, here

Joule Unlimited Receives an Patent for Genetically Engineered Cyanobacteria

Posted by Stella Kin

Just two weeks ago
Joule Unlimited Receives an Patent for Genetically Engineered Cyanobacteria
Patent

Not technically an algae though...

Backtracking...

Posted by Stella Kin

I wish I found this three weeks ago. It gives all the recommended manufacturing specifications from start to finish for Chlorella vulgaris. Useful as a backup anyway:

Microalgae as feedstock for biodiesel production: Carbon dioxide sequestration, lipid production and biofuel quality

Algae to consider

Posted by Stella Kin

NSF Grant to NC State U. for Algae Biofuel from Dunaliella

Finally a bit of a breakthrough, given how secretive all the universities and companies are being with their algae-oil research. I think we could consider this as our algae of choice. It's potentially oil-secreting, North Carolina State University are currently studying it, it's a well researched strain, used to find ways in which to improve biomass and oil production, and it's already being commercially used. I'll comb over the previous research to find other references to it. If we combine this with either one of the manufacturing processes already discussed or use the solar panel idea that Ramachandra proposes, I think we'll have something very interesting.

On the negative side, I don't think it's a diatom.

*******************
Also

Microbes reprogrammed to ooze oil for renewable biofuel

In this case cyanobacteria (blue-green algae) but it doesn't say which.

MSU: Baking soda dramatically boosts oil production in algae

Posted by Stella Kin

This was only three weeks ago. Something to consider...

MSU: Baking soda dramatically boosts oil production in algae

Start-up says it's turning algae into gasoline

Posted by Stella Kin

Sapphire energy says they're already doing it:

Start-up says it's turning algae into gasoline

Companies Exploring GM Algae Production

 Posted by Rachel

D. Glass Associates Inc. is a biotechnology consulting company. The CEO wrote a blog to follow up information obtained at the EUEC 2010 conference (2nd February 2010) and to complement a presentation that he gave.  This blog gives a comprehensive list of companies that are looking into genetically modifying algae (and how) in order to obtain greater oil yield.  The blog, and therefore the list of companies, can be found at:

http://dglassassociates.wordpress.com/2010/03/17/companies-reported-to-be-developing-genetically-modified-algae-for-biofuels/

The presentation that Dr. Glass gave at the EUEC 2010 conference was entitled "Prospects for the use of Genetic Engineering in Biofuel Production" and the slides from the presentation can be accessed here: http://www.slideshare.net/djglass99/david-glass-euec-presentation-02-02-10

The information given in this presentation and in the blog is useful for determining which companies are at a commercial stage in their GM-Algae production (not that many!) and seeing where current research into this is currently at. There is also an interesting slide in the presentation which details business deals involving biofuels.  Relevant ones are:

• Chevron/Solazyme: biodiesel production from algae
• ExxonMobil/Synthetic Genomics: synthetic algal strains for biofuel production
• Royal Dutch Shell/HR Petroleum: marine algae for biofuel

It may be too late in the project to start researching these deals from scratch but at least we have evidence of large multinational comapnies investing huge amounts of money into what we are trying to achieve. Therefore implying that our pitch is not a waste of time/money.

Notes on diatoms

Posted by Stella Kin

• Diatoms are a kind of unicellular algae belonging to the algal class Bacillariophyceae.
• Diatoms are responsible for about one-fifth of the photosynthesis carried out on earth, and, like other
  primary producers, sequester carbon.They are estimated to fix at least 25-30% of the global carbon dioxide. 
• Under culture conditions, algal populations can double in size in a few hours, and are more effective absorbers of carbon than higher plants.
• Theoretical calculations based on the photosynthetic ability and growth potential of diatoms have
  shown that diatoms can yield more than 30,000 litres (or 200 barrels) of oil per hectare per annum. 
• Traditionally used crops for the production of biofuels such as oilseeds have an oil content of lesser than 5% of their total mass. Diatoms can yield 100–200 times as much oil as soybean, 10–200 times more than oil seeds and 7–31 times more than oil palm, which is considered as the next best source of oil1.
• Scientists have also found out that diatoms produce more oil (double or even triple the amount produced normally) under photo-oxidative stress or nutrient starvation such as lower nitrogen or silica content in the growth media. This is due to the shift in lipid metabolism from membrane lipid synthesis to the storage of neutral lipids
• the ‘pure’ diatom oil contains an estimated 60–70% saturates. The diatom oils are likely to be rich in fatty acids, which during early diagenesis, reportedly transform into condensed lipids1’.
• Ramachandra and his group have worked out a concept which ‘cuts down’ the time required to produce oil from diatoms from ‘millions of years to daily’. 
• They have suggested a way in which diatoms can be made to work like mammalian glands, so that one can ‘milk’ oil from them continuously for long periods of time. The diatoms will be designed such that they secrete the oil that they produce rather than store it, so that they need not be destroyed to obtain oil, and a continuous supply of oil is ensured. 
• ‘Milking’ diatoms would serve to do away with the cumbersome process of extraction of oil
  from them.
• The team has also proposed the design of a solar panel based on the structure of an angiosperm leaf – the epidermis, the outermost layer of the leaf, would be the solar panel; the inner tissues of the leaf, such as the palisade and spongy tissues that are responsible for much of the carbon fixation and photosynthesis, will be the photosynthetic diatoms

• Conditions for optimum production of oil will be provided. 
• Additionally, they have also suggested genetic manipulation of diatoms so that they produce gasoline directly instead of ‘crude oil’ from which gasoline must then be obtained. 
• In other words, they have envisioned a ‘solar panel that converts photons to gasoline rather than electricity or heat’1.

• The first step is to culture various diatoms and identify species that have higher oil content, and those that have a faster growth in low cost growth media. Also required are diatoms that would be thermophilic (they must be able to survive high temperature conditions of the solar panel), able to survive in the hydrocarbon mixture that they would exocytose, and have a highly efficient photosynthetic capacity. 
• The second step is the design of the solar panel and genetic modification of the diatoms to get a system that would give a continuous supply of oil. Ramachandra et al. have also suggested the engineering of an angiosperm leaf with a symbiotic association with diatoms – the diatoms can replace the photosynthetic mesophyll tissue of the leaf while the leaf helps in gaseous exchange and also provides a humid environment for the growth of diatoms. 
• Another step is the genetic engineering of diatoms to make them produce gasoline directly so that the secretion can be used without further processing and modification. 

These various ‘steps’ may take a number of years, or may even happen simultaneously through collaboration.

Reference
Milking diatoms – a new route to sustainable energy

The links in the article don't lead anywhere, here are the results of a search done within Newcastle's website:
‘UK dream team’ to develop algae biofuel

Minutes for meeting 6

Friday 26 November

Present: Stella Kin, Louise Anton, Bryan McCulloch, Rachel Nichol

Next meeting: Monday 29 November, 12pm Butchart

1. Discussion of research

Discussion of whether to improve manufacturing processes to increase biomass yield (flashing LEDs, nitrogen supply, etc) or oil yield (extraction process, electromagnetic ultrasound wave), or to invest money into genetic engineering (using oil-secreting diatoms). It was felt that cutting and pasting a number of improvements together would make it quite difficult to sell at the presentation, because of the variety of algae types that have been used, and this would also make procjecting yields very difficult. The best options are to either research into one area of improvement for one type of algae, or to research a particular algae that can be genetically engineered to improve yield. The consensus in the meeting was to opt for the latter and that further reading should be done into oil secreting diatoms. 

Oliver suggested looking into government subsidies but Bryan has found none as of yet. 

2. Discussion of presentation

Each team member will present their own section of research. The research should be distilled into a few sentences, bullet points and images that can be included in the slides. Recommended no more than 2 slides and 2 minutes per person.

3 Any other business

Team will meet on Monday at Butchart to compare research into diatoms and GM, and start to put slides together.

Actions

1. All team members to research on oil secreting diatoms and post links and paper on the blog

2. All to prepare their research so far to put into slides

Possible idea for a business plan?

By Bryan McCulloch

http://www.biomara.org/
Found this site through looking at the literature I had. This is a joint partnership between the UK and Ireland which is looking at using microalgae and seaweeds as a biofuels. The outline they have is similar to what Oliver was talking about today as a long term plan

Agenda for Meeting 6

26 November 2010

1. Discussion of research so far
2. Discussion of start-up company objectives, whether to improve exisiting manufacturing processes or to invest money into GM research
3. Discussion of presentation
4. Any other business

'Milking Algae' for Oil

'Milking' Microscopic Algae Could Yield Massive Amounts Of Oil

Milking diatoms – a new route to sustainable energy

Genetic Engineering of Algae for Enhanced Biofuel Production

There's plenty of research being done outside of Synthetic Genomics.

Other links
http://www.technologyreview.com/energy/22572/
http://www.economist.com/node/14029874?story_id=14029874
http://wgbis.ces.iisc.ernet.in/energy/water/paper/RG_260409_Ramachandra&2008v35/news.htm

Algomed - algae farm in Klötze Germany

Posted by Stella Kin

Algomed - Europe’s largest microalgae production plant began in Klötze (in 1999?)

Their choice of algae is Chlorella vulgaris, to make supplements and food.

The website says:

Light can reach the algae from all sides through the glass tube, i.e. they are exposed to maximum light and can grow well.

They don't make the use of the cycling through light and dark zones science to maximise photosynthesis. I don't know why this is.

Algae to be considered

Posted by Stella

Algae (as opposed to other plants) are a natural choice for maximum-yield biofuels because they: 

1. intrinsically offer the greatest flux tolerance and photosynthetic efficiency as a consequence of a minimum of internally competitive plant functions, 
2. enjoy fast reproductive cycles, 
3. have limited nutrient requirements, and 
4. can readily be exposed to temporal and spectral irradiation distributions and intensities that are not encountered in nature but are optimal for bioproductivity via cleverly crafted photonic systems.

Those most widely utilized for current commercial applications belong to the genera Chlamydomonas, Chlorella, Haematococcus, and Dunaliella. 

Diatoms, a group of silicon-rich microalgae, and prokaryotic cyanobacteria also offer substantial opportunities for metabolic engineering and biotechnology.

Reference

A green light for engineered algae: redirecting metabolism to fuel a biotechnology revolution

Airlift bioreactor links

Posted by Stella Kin

Airlift bioreactor uses oscillating microbubbles to boost algae yields by 30 percent
Uses 18% less energy than standard sparging systems. The generator improves the performance of air-lift loop bioreactors (ALBs) by producing smaller bubbles, around 20 micrometers versus 1–3-mm diameter for sparging. Produces 30% more algae than one fed with conventionally produced bubbles. Microbubbles of CO₂ dissolve faster, keep the suspension well mixed, and also help remove oxygen (which is toxic to algae).

I can't access the paper but the bioreactor is patented so maybe we can access the design elsewhere?

Air-Lift Bioreactors for Algal Growth on Flue Gas: Mathematical Modeling and Pilot-Plant Studies
The lines between airlift and bubble bioreactors are becoming quite blurred. I think this might be in reference to the triangular design from MIT.

Bubble Column Reactors - some links to more information

Posted by Rachel

1) You might want to check out this link: http://www.springerlink.com/content/p723m816122n6267/

It takes you to a book which has a pretty comprehensive chapter (chapter 8) on bubble column reactors plus some diagrams and so on. It gives examples of different types of bubble reactor and some applications. Some of the content is restricted (unless you want to pay for it) but you're able to read a few pages before it decides to blur out the rest.

2) Also this link: http://ct-cr4.chem.uva.nl/structuredbc/ from the University of Amsterdam

It has some excellent pictures of reactors and a comprehensive theory section which is good for getting some solid background information on  the reactors.


3) Also see this link: http://www.scribd.com/doc/26979880/Bubble-Column-Reactors

It takes you to a collection of slides which have some good schematic diagrams plus some pictures of reactors and also goes into the modelling aspect of these reactors.

MIT algae photobioreactor

Posted by Stella Kin

MIT algae photobioreactor

Link to youtube video of their triangular reactor.

One of the latest developments is the triangular reactor (Fig. 5). It combines the principle of a bubble column with mixing by in-built static mixers in an external ‘downcomer’. According to press releases from MIT and an external evaluation [139] this “3DMS-Reactor” exhibits an average productivity of 98 g dry weight m−2 day−1 over a period of 19 days even when under sub-optimal lighting conditions. Thus, this is one of the most productive algal cultivation systems ever built, and verges on the theoretical maximum average yield of 100 g m−2 d−1

Reference
Second Generation Biofuels: High-Efficiency Microalgae for Biodiesel Production

Minutes for meeting 5

Posted by Stella 
 

Wednesday 24 November

Present: Stella Kin, Louise Anton, Bryan McCulloch, Christopher Sanderson
Apologies: Rachel Nichol 

Next meeting:  Friday 26 November 

1. Discussion of research so far

Louise reiterated that the environmental and societal implications of algal biofuels were limited. Carbon off-setting can be applied through attaching bioreactors to powerstations to use as a source of CO2, using wastewater, and using the remaining biomass as fuel or to sell.

Bryan said from his research, GM looked promising for the future but there isn't anything viable at the moment. Discussion moved to other ways of maximising biomass output and oil output by reducing nitrogen input and light input.

Stella detailed the photobioreactor designs currently available. The most promising are the tubular design and vertical column bubble reactors. There was some concern whether a solar dependent bioreactor would be effective in Scotland, or whether an LED powered bioreactor would be prohibitively expensive. Once the algae type was settled on, comparative yields could be calculated.

2. Decision on photobioreactor design

The choices are narrowed down to tubular structure and vertical column bubble reactors. Team will continue to research these two before making a final decision on Friday.

3. Decision on GM

GM options are to be placed on hold for the moment.

4. Decision on algae

There was no consensus on which was best. By discounting GM as an option, the team should research and choose the algae with the highest yield and best suited to the conditions

5. Any other business

Possibilty of a Saturday or Sunday meeting so that we can stay on schedule for presentation rehearsal start on Monday. Louise gave her apologies as she will not be able to make a weekend meeting or the Monday one.

Chris suggested summarising some of our information and where we are up to on the weblog.

Louise and Bryan had problems logging in to the weblog. Stella suggested in future in the event of weblog failure, to email the information to her to try to post.

Mamen also stated that it would be acceptable to invest all of the money into research if an avenue looked viable. She also suggested writing a summary of the information we have accumulated so far for our own reference.

Action

1. Stella to reorganise some of the pbr research so that it is more user friendly as soon as possible.

2. Team to research tubular photobioreactors and vertical column bubble reactors, using the weblog as a starting point.

3. Team to look at most suitable algae type to use. Some of this information is embedded in the links in the weblog so Stella will dig it out and repost it.

4. Team to distill their research notes into short bullet points ready to paste into the presentation slides.

5. Chris to post a short summary of our work so far on the weblog.

6. Any other research still to go on the weblog should be posted as soon as possible.

Agenda for Meeting 5

Posted by Stella Kin 

24 November 2010
1. Discussion of research so far
2. Decision on photobioreactor design
3. Decision on incorporation of GM
4. Decision on algae
5. Any other business

Photobioreactor design

Posted by Stella Kin 

Design of Scaleable Photobioreactors for Mass Production of Algae for Biofuel Production 

A presentation from the University of Arizona on photobioreactors on open raceways and vertical bubble columns. 

Comparative evaluation of compact photobioreactors for large-scale monoculture of microalgae
Paper compares horizontal tubular photobioreactors and vertical bubble column and airlift vessel type photobioreactors and concludes that vertical reactors appear to be the only ones that can be effectively used in large-scale culture of microalgae. 

Bubble columns are more scaleable and provide a relatively homogeneous culture environment. In addition, the low surface– to–volume bubble columns demand less cooling. Vertical columns experience less photoinhibition during periods of high light intensity; during low light seasons such as winter, the vertical
reactors still receive substantial total radiation because they receive more reflected light than do
horizontal tubes.  

Photobioreactors for mass cultivation of algae (2007)
Another comaprison paper. See Table 1 or see below: 

Open ponds  

Adv: Relatively economical, easy to clean up after cultivation, good for mass cultivation of algae
Disadv: Little control of culture conditions, difficulty in growing algal cultures for long periods, poor productivity, occupy large land mass, limited to few strains of algae, cultures are easily contaminated

The best annual averaged bioproductivity of outdoor open algal ponds is ∼1 g dry weight m−2 h−1, while corn, sugar cane, and closed algal photobioreactors have achieved ∼2–3 g dry weight m−2 h−1

Vertical-column photobioreactors  

Aerated vertical columns

Air-lift bioreactors are similar to bubble column reactors, but differ by the fact that they contain a draft tube which improves circulation and oxygen transfer and equalizes shear forces in the reactor. The more homogeneous distribution of exposure time or higher hydrodynamic stress in the airlift reactor resulted in a higher growth rate. (See link) 

Vertical bubble columns

Adv: High mass transfer, good mixing with low shear stress, low energy consumption, high potentials for scalability, easy to sterilize, readily tempered, good for immobilization of algae, reduced photoinhibition and photo-oxidation
Disadv: Small illumination surface area, their construction require sophisticated materials, shear stress to algal
cultures, decrease of illumination surface area upon scale-up 

Flat-plate photobioreactors 

u-shaped disposable plastic bag located between two iron frames. Frame and plastic bag are 1.5m high and 2.5m long, with a volume of 250 L.

Adv: Large illumination surface area, suitable for outdoor cultures, good for immobilization of algae, good light path, good biomass productivities, relatively cheap, easy to clean up, readily tempered, low oxygen buildup 

Disadv: Scale-up require many compartments and support materials, difficulty in controlling culture temperature, some degree of wall growth, possibility of hydrodynamic stress to some algal strains 

Tubular photobioreactors  

Adv: Large illumination surface area, suitable for outdoor cultures, fairly good biomass productivities, relatively cheap
Disadv: Gradients of pH, dissolved oxygen and CO2 along the tubes, fouling, some degree of wall growth, requires large land space 

References

Second Generation Biofuels: High-Efficiency Microalgae for Biodiesel Production - Shenk 2007

Evaluation of GreenFuel’s 3D Matrix Algae Growth Engineering Scale Unit - 2007
University of Arizona - Cuello

Characterization of a flat plate photobioreactor for the production of microalgae - 2007
Photobioreactor Design for Commercial Biofuel Production from Microalgae
Comparison of photobioreactors for cultivation of Undaria pinnatifida gametophytes

Some Papers Which May Be Useful

Posted by Bryan McCulloch

Biodiesel from algae: challenges and prospects
A paper which outlines all the things which should be considered when developing an algae bioreactor

Renewable fuels from algae: An answer to debatable land based fuels
A paper which compares algae biofuel production to that of 1st and 2nd generation biofuels

The economics of producing biodiesel from algae
A paper which gives an outline of costs for a (theoretical) large biodiesel refinery. Costing is done in US$

Commercialization potential of microalgae for biofuels production
A critical analysis of algae biofuel production and possibilities

Genetic engineering of algae for enhanced biofuel production
Paper which Stella posted earlier, which gives a good insight into the type of work which is being carried out into increasing oil reserves in the algae and other related ideas

Selection for fitness at the individual or population levels: Modelling effects of genetic modifications in microalgae on productivity and environmental safety
A paper which gives a theoretical model of genetically modified algae behaviour. The work is non-algae specific, i.e. just gives a general idea of what could happen, but is quite an interesting read

Light saturation and photoinhibition

Posted by Stella Kin 

Above a certain value of light intensity, a further increase in light level actually reduces the biomass growth rate (see figure) – photoinhibition – at light intensities only slightly greater than the light level at which the specific growth rate peaks.

Photoinhibition results from generally reversible damage to the photosynthetic apparatus, as a consequence of excessive light.

There are lots of papers that detail methods to overcome photoinhibition. 

Gordon (2007) advocates irradiating the algae with intense microsecond pulses of intense red light. Through turbulence, the algae are therefore cycled through light and dark zones at high frequency, allowing an increase in the algae's flux tolerance to light. Projected annual algal biomass yields could be increased from 1g dry weight m-2 h-1, to 100g.

Manufacturing processes of algae biofuels

Posted by Stella Kin 

Microalgae are sunlight-driven cell factories that convert CO2 to potential biofuels, foods and feeds.

Biodiesel production

The parent oil consists of triglycerides. It is reacted with methanol (transesterification) producing methyl esters of fatty acids, that are biodiesel, and glycerol.

Yields of methyl esters exceed 98%. The biodiesel is recovered by repeated washing with water to remove glycerol and methanol.

Biomass production

• Photosynthetic growth requires light, carbon dioxide, water and inorganic salts (N, P, Si).
• Temperature must remain generally within 20 to 30 °C.
• To minimize expense, biodiesel production must rely on freely available sunlight, despite daily and seasonal variations in light levels.

Raceway ponds

• Closed loop recirculation channel
• 0.3m deep
• Mixing and circulation by paddlewheel
• Built in concrete or compacted earth, may be lined with white plastic

During daylight, the culture is fed continuously in front of the paddlewheel where the flow begins Broth is harvested behind the paddlewheel, on completion of the circulation loop. The paddlewheel operates all the time to prevent sedimentation.

The largest raceway-based biomass production facility occupies an area of 440,000 m2 (Earthrise Nutritionals).

Disadvantages

1. Temperature fluctuates within a diurnal cycle and seasonally.
2. Evaporative water loss can be significant.
3. Because of significant losses to atmosphere, raceways use carbon dioxide much less efficiently than photobioreactors.
4. Productivity is affected by contamination with unwanted algae and microorganisms that feed on algae.
5. The biomass concentration remains low because raceways are poorly mixed and cannot sustain an optically dark zone.

Raceways are perceived to be less expensive than photobioreactors, because they cost less to build and operate. Although raceways are low-cost, they have a low biomass productivity compared with photobioreactors.

Photobioreactors

Unlike open raceways, photobioreactors permit essentially single-species culture of microalgae for prolonged durations.

A tubular photobioreactor consists of an array of straight transparent tubes that are usually made of plastic or glass. This tubular array, or the solar collector, is where the sunlight is captured.

Light

• Solar collector tubes 0.1m or less in diameter. Tube diameter is limited because light does not penetrate too deeply in the dense culture broth that is necessary for ensuring a high biomass productivity of the photobioreactor.
• Microalgal broth is circulated from a reservoir (i.e. the degassing column) to the solar collector. to increase reflectance, and back to the reservoir.
• The solar collector is oriented to maximize sunlight capture. In a typical arrangement, the solar tubes are placed parallel to each other and flat above the ground.

Instead of being laid horizontally on the ground, the tubes may be made of flexible plastic and coiled around a supporting frame to form a helical coil tubular photobioreactors.

• Artificial illumination of tubular photobioreactors is technically feasible, but expensive compared with natural illumination. (See later)

Flow

• Biomass sedimentation in tubes is prevented by maintaining highly turbulent flow. Flow is produced using either a mechanical pump (can damage biomass), or a gentler airlift pump.

CO2

• The culture must periodically return to a degassing zone that is bubbled with air to strip out the accumulated oxygen. Typically, a continuous tube run should not exceed 80 m
• Carbon dioxide is fed in the degassing zone in response to a pH controller. Additional carbon dioxide injection points may be necessary at intervals

Temperature

• Outdoor tubular photobioreactors are effectively and inexpensively cooled using heat exchangers. Large tubular photobioreactors have been placed within temperature controlled greenhouses (Pulz, 2001), but doing so is prohibitively expensive for producing biodiesel.

Comparison of raceways and tubular photobioreactors

Variable	Photobioreactor facility	Raceway
Annual biomass production (kg)	100000	100000
Volumetric productivity (kg m-3 d-1)	1.54	0.12
Areal productivity	0.048 a 0.072 c	0.045 b
Biomass concentration in broth (kg m-3)	4	0.14
Dilution rate (d-1)	0.38	0.25
Area needed (m2)	5681	7828
Oil yield (w3 ha-1)	136.9 d 58.7 e	99.4 d 42.6 e
Annual CO2 consumption (kg)	183333	183333
System geometry m2/pond	132 parallel tubes / unit 80m long tubes 0.06 m tube diameter	978 12 m wide 82 m long 0.3 m deep
Number of units	6	8

a Based on facility area.

b Based on actual pond area.

c Based on projected area of photobioreactor tubes.

d Based on 70% by wt oil in biomass.

e Based on 30% by wt oil in biomass

Conclusion

Photobioreactors provide much greater oil yield per hectare compared with raceway ponds. This is because the volumetric biomass productivity of photobioreactors is more than 13-fold greater in comparison with raceway ponds

Harvesting

Recovery of microalgal biomass from the broth is necessary for extracting the oil. Biomass is easily recovered from the broth by filtration, centrifugation, and other means. Cost of biomass recovery can be significant. Biomass recovery from photobioreactor cultured broth costs only a fraction of the recovery cost for broth produced in raceways. This is because the typical biomass concentration that is produced in photobioreactors is nearly 30 times the biomass concentration that is generally obtained in raceways (see table). Thus, in comparison with raceway broth, much smaller volume of the photobioreactor broth needs to be processed to obtain a given quantity of biomass.

Economics

Recovery of oil from microalgal biomass and conversion of oil to biodiesel are not affected by whether the biomass is produced in raceways or photobioreactors.

Hence, the cost of producing the biomass is the only relevant factor for a comparative assessment of photobioreactors and raceways for producing microalgal biodiesel.

From table, estimated cost of producing microalgal biomass per kg is:

                                                       100 tonnes             10,000 tonnes

photobioreactors                             $2.95                       $0.47

raceways                                         $3.80                       $0.60  

economies of scale

and assuming CO2 at zero cost.

Assuming biomass contains 30% oil by weight, cost of biomass for providing a litre of oil:

photobioreactors           $1.40

raceways                       $1.81

Oil recovered from lower-cost biomass produced in bioreactors is estimated to cost $2.80/L. This assumes that recovery process contributes 50% to the cost of the final recovered oil.

A reasonable target price for microalgal oil is $0.48/L for algal diesel to be cost competitive with petrodiesel (in the US).

Improving economies using biorefineries

• residual biomass to produce animal feed
• anaerobic digestion to produce methane for generating electrical power to run the facility

Enhancing algal biology

1. increase photosynthetic efficiency to enable increased biomass yield on light;
2. enhance biomass growth rate;
3. increase oil content in biomass;
4. improve temperature tolerance to reduce the expense of cooling;
5. eliminate the light saturation phenomenon so that growth continues to increase in response to increasing light level;
6. reduce photoinhibition that actually reduces growth rate at midday light intensities that occur in temperate and tropical zones; and
7. reduce susceptibility to photooxidation that damages cells.
   
   
   Reference 
   Biodiesel from microalgae - Christi, 2007