Monthly Archives: April 2012

The CCRES Algae Production Module

 

CCRES Algae
The CCRES Algae Production Module will begin with an overview of photosynthesis and the carbon cycle, the taxonomy of algae and the basics of cell biology.
Safety in the lab, OSHA compliance and the process of experimental methodology are also included in the curriculum. Students will learn about algae growth factors such as temperature, light, CO2and nutrients.
 The different kinds of photobioreactor designs will be explored, including closed vs. open systems.  Students will learn about the importance of cultivation protocols, and when to feed, harvest and how to process the algae.
 Analytics will be covered as well which includes the use of the microscope and learning about the basic algae handling and testing procedures such as dilution, cell counting and dry weight measurment.
The various uses of algae will be examined such as its role in the nutraceutical, food, cosmetic and animal feed industries and as a replacement for petroleum as a transportation fuel.
CCRES ALGAE PROJECT
part of 
CROATIAN CENTER of RENEWABLE ENERGY SOURCES (CCRES)
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Human growth hormone (HGH) from algae

 

 

Rehovot, Israel-based Rosetta Green Ltd., which specializes in crop improvement for the agriculture and alternative fuel industries using unique genes called microRNAs, has successfully completed an experiment producing human growth hormone (HGH) and validated its biological activity. Proteins produced by both treated and control algae were tested with an in vitro activity test assay by an independent third party using the conventional proliferation method. The activity test assay found that Rosetta Green’s treated algae exhibited hormonal activity.

The project is part of a joint European effort to manufacture chemicals and proteins in algae, which is implemented and funded by the European Union as part of the European Commission’s Seventh Framework Program for Research and Technology Development (FP7). More than ten European organizations are participating in this project, including companies and leading universities, which has an estimated budget of about $7 million US. The project is being managed by Professor Sammy Boussiba of the Microalgal Biotechnology Laboratory of Ben Gurion University of the Negev.
Rosetta Green focuses on using microalgae to develop and produce human proteins for therapeutics, a process that reduces the currently steep drug production costs associated with using mostly mammalian cells and bacteria.

According to Amir Avniel, Rosetta Green’s CEO, “Algae may be an effective source for the production of proteins and vaccines. Rosetta Green has vast experience working with molecular methods in algae. The company worked on the development of designated algae in order to produce the protein in cooperation with the EU. Algae can be used for multiple applications such as producing chemicals, industrial food supplements, bio fuel and food. We believe that the technology that we develop provides significant advantage to improve various traits in plants and algae. We continually seek partners to develop our products and technologies.”

Growth hormone is a peptide hormone secreted by the pituitary gland. Among its functions are the regulation of protein production and the stimulation of bone growth in children. Growth hormone is normally secreted throughout a person’s life, but the amount decreases by 14% every decade after the age of 21. A deficiency in this hormone is known to cause growth block, short stature and dwarfism.

Currently, growth hormone is produced by major multi-nationals such as Pfizer, Lilly, and Merck Serono and used as a prescription medicine to treat children with growth problems and adults with hormone deficiency as well as other symptoms characterized by growth complications. Total annual sales of human growth hormone are estimated at approximately $3 Billion US.

Growth hormone is administered today primarily through daily injections over several years. The accumulated cost can reach hundreds of thousands of dollars per child. Rosetta Green believes that manufacturing the hormone using microalgae will likely reduce today’s high cost of production, which relies upon currently available techniques.

More info at http://www.rosettagreen.com/.

CCRES special thanks to Professor Sammy Boussiba of the Microalgal Biotechnology Laboratory of Ben Gurion University of the Negev.

 

CCRES ALGAE Project 

part of

Croatian Center of Renewable Energy Sources (CCRES)

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CCRES ALGAE PROJECT

 

 

 
 
 
CCRES ALGAE PROJECT
 
Algae is uniquely suited to serve as the foundation for a new generation, the next industrial age of renewable and low carbon transportation fuels. It addresses and solves many of the pressing issues of our time, from climate change, to energy security, to jobs. It sets an infrastructure that will require fewer compromises and more reliance on ourselves to feed our own energy consumption needs.

Algae is one of nature′s most prolific and efficient photosynthetic plants; in fact, it is the source of the earth′s crude oil when algae bloomed millions of years ago. Nearly all of algae′s energy is concentrated in the chloroplast—the engine that turns sunlight and CO2 into organic carbon, resulting in oils easily refined into gasoline, diesel, and jet fuel. Further, algae has a short growing cycle and does not require arable land or potable water. Algae′s number one nutrient source is CO2, consuming 13 to 14 kg of C02 per gallon of green crude. Algae can be grown quickly in salt water in the desert.

 
The process for making algae into fuel at a very base level is this: Sunlight and CO2 are the source of energy and carbon dioxide, rather than sugar or other organic material. By applying the principals used in biotechnology, CCRES can produce oil in algae that is highly branched and undecorated – the way that traditional crude is – to get a biological crude molecularly similar to light sweet crude. This Green crude can be than processed at a refinery just as traditional crude to make all three major distillates – gasoline, diesel, and jet fuel.
 
Algae are the most efficient photosynthetic plants on the planet as no energy goes into making roots, stems, seeds, or flowers. More energy (roughly 6-50 times more) is produced per acre, per year, with algae versus other feedstocks.
 
CCRES ALGAE PROJECT
part of 

Croatian Center of Renewable Energy Sources (CCRES)

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Indirect land-use change (ILUC)

‘Indirect land-use change’ (ILUC) means that if you take a field of grain and switch the crop to biofuel, somebody somewhere will go hungry unless those missing tonnes of grain are grown elsewhere.
Economics often dictates that the crops to make up the shortfall come from tropical zones, and so encourage farmers to carve out new land from forests.
Burning forests to clear that land can pump vast quantities of climate-warming emissions into the atmosphere, enough in

theory to cancel out any of the benefits that biofuels were meant to bring.
The European Commission has run 15 studies on different biofuel crops, which on average conclude that over the next decade Europe’s biofuels policies might have an indirect impact equal to 4.5 million hectares of land – an area the size of Denmark.
Some in the biofuels industry argue that the Commission’s science is flawed and that the issue could be tackled by a major overhaul of agricultural strategy to improve productivity or by pressing abandoned farmland back into action. Waste products from biofuels production can also be fed to animals, they say, so reducing the pressure on land resources.

Conventional biofuels like biodiesel increase carbon dioxide emissions and are too expensive to consider as a long-term alternative fuel, a draft EU report says.
The study ‘EU Transport GHG [greenhouse gases]: Routes to 2050’ estimates that before indirect effects are counted, the abatement cost of reducing Europe’s emissions with biofuels is between €100-€300 per tonne of carbon.
At current market prices, this would make their CO2 reduction potential up to 49 times more expensive than buying carbon credits on the open market at €6.14 a tonne.
But the EU’s authors conclude that it “it is not possible (and useful) to determine cost effectiveness figures for [conventional] biofuels” because their indirect effect – measured in cleared forests and grasslands (‘ILUC’) – make it a CO2-emitting technology.
The latest report will feed a growing unease about the reasons for the EU’s original biofuels policy – justified in environmental terms – and the way it has developed since.
“The truth is that policy makers inside and outside Europe are doing biofuels for other reasons than environmental ones,” said David Laborde, a leading agricultural scientist and author of key biofuels reports for the European Commission.
“It’s a new and easy way to give subsidies to farmers, and it’s also linked to industrial lobbies that produce these biodiesels, and also what they will call energy security,” he told EurActiv.
“They want to diversify the energy supply, and keep their foreign currencies instead of buying oil from the Middle East. They prefer to keep it for something even if it is not efficient or even green,” he added.
The ‘10% target’
In 2007, the EU first set a 10% target for the use of blended biofuels in transport by 2020.
Although the target was re-sourced from ‘biofuels’ to ‘renewable energy’ in 2009, analysts say that 8.8% of the EU target will still be provided by biofuels, and up to 92% of that will come from conventional biofuels like biodiesel.
Industrial associations disagree, putting the EU’s ratio of sugar-based ethanol, one of the best-performing biofuels, to biodiesel, one of the worst, at 22%-78%.
But both the original announcement and the Renewable Energy Directive two years later conditioned biofuel use on subsequently neglected criteria of cost-efficiency, sustainability and, where available, the use of second generation fuels.
“I don’t think we are there on cost-effectiveness,” said Géraldine Kutas, Brussels representative of the Brazilian Sugarcane Industry Association (UNICA).
“There are no monetary provisions to support this in the directive, and second generation biofuels are still a promise. They are not commercially available yet,” she said.
Even trying to address the issue of indirect sustainability criteria for biofuels had gummed up the EU’s policy-making process, she acknowledged.
French farmers
Research by EurActiv has uncovered evidence that the EU’s original biofuels target was set as much for industrial and political reasons, as environmental concerns.
Claude Turmes, the European Parliament’s rapporteur responsible for steering the Renewable Energy Directive into law, said that business lobbies had influenced his negotiations with the then-French Presidency of the European Council.
“There were two lobbies, the sugar farmers lobby and the German car industry who tried to prevent the EU’s CO2 and cars legislation,” Turmes (Greens/Luxembourg) told EurActiv.
“The origin of the 10% renewables in transport target was the fact that these two lobbies joined forces to impose it on the Commission.”
EU insiders spoken to by EurActiv agreed, saying that biofuels had been a quid-pro-quo demanded for the imposition of ‘greener’ measures in the directive that would encourage wind and solar energy, and cut emissions.
European sugar farmers had suffered in the 2006 Common Agricultural Policy reform which reduced the guaranteed sugar price by 36% and opened up the European sugar market to global competition.
A guaranteed market for agrifuel made from sugar-based ethanol held out some prospect of compensation. And the strength of the French farmers lobby made removing the 10% target “an absolute no go area” for Paris, Turmes said.
“The farm industry was obviously interested in biofuels, biochemicals and the bio-economy more generally,” Kutas added.
But Europe’s sugar farmers profited far less from the EU’s biofuels policy than growers of feedstocks for biodiesel, better suited to the continent’s diesel-based auto fleet.
Car industry
EU officials say that the car industry was also instrumental in pushing for the biofuels target to be included as a compromise to bridge the gap between the 130g of CO2 per km that the EU wanted as a target for 2012 and the 140g that the car industry was prepared to offer.
“It was no secret,” a source told EurActiv. “It was very clear what they were lobbying for and it went all the way up the Commission”.
As a result, officials in the EU’s energy directorate responsible for biofuels did not treat research which questioned the fuel’s environmental credentials in the same light as that which supported it, multiple sources confirm.
The EU’s biggest error was “that we started to make a policy without knowing the effect it would have,” Laborde said.
“We are now discussing the land use effect after saying for ten years that we need biofuels to reduce emissions,” he went on. “It was a serious mistake.”
Indirect emissions proposal
Brussels is due to publish a proposal measuring the indirect emissions caused by biofuels later this year, distinguishing between low-emitting biofuels such as ethanol and high-emitting ones like biodiesel.
But the EU’s decision-making process has been paralysed by the ongoing dispute between its energy directorate – which does not want ILUC factors considered – and its climate directorate, which does. And there are other problems too.
Both the Renewable Energy and Fuel Quality directives contain ‘grandfathering’ clauses exempting all existing biofuels installations as of 2014 from further legislation until 2017.
As the biofuels industry’s existing capacity is already on the cusp of meeting the 10% target, according to a new report by the environmental consultants Ecofys, this would create massive overcapacity.
The Institute for European Environmental Policy has calculated that on current trends, land conversion of between 4.7 million and 7.9 million hectares would be needed to accommodate the extra biofuels production, an area roughly the size of Ireland.
But the introduction of any ILUC factor would probably rule out high-emitting conventional biodiesels, the majority of Europe’s biofuels production.
That would create a political backlash in EU states such as France and Germany, and potentially tear up the compromise which allowed the Renewable Energy Directive to be passed in the first place.
For now, the proposal remains stuck in the corridors of an EU that appears equally frightened of the political consequences of admitting a policy mistake and the environmental consequences of denying it.
CCRES special thanks to
Brussels Network Office:
International Press Centre
Boulevard Charlemagne, 1 b1
B-1041 Brussels

CROATIAN CENTER of RENEWABLE ENERGY SOURCES (CCRES)

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HAPPY EASTER

 

 

HAPPY EASTER

 

May your Easter be blessed with health,

longevity, love and a lot of happiness!

 

CCRES Team

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Biomass-Based Fuel Supplements

The Department of Energy (DOE) has announced up to $15 million available to demonstrate biomass-based oil supplements that can be blended with petroleum, helping the United States to reduce foreign oil use, diversify the nation’s energy portfolio, and create jobs for American workers.
Known as “bio-oils,” these precursors for fully renewable transportation fuels could be integrated into the oil refining processes that make conventional gasoline, diesel, and jet fuels without requiring modifications to existing fuel distribution networks or engines.
The Department expects to fully fund between five to ten projects in fiscal year 2012 to produce bio-oil prototypes that can be tested in oil refineries and used to develop comprehensive technical and economic analyses of how bio-oils could work. The proto-type bio-oils will be produced from a range of feedstocks that could include algae, corn and wheat stovers, dedicated energy crops or wood residues.
 Domestic industry, universities, and laboratories are all eligible to apply.
The results of the projects will inform future efforts directed at advancing bio-oil technologies and bringing these renewable fuels to market. A description of the funding opportunity, eligibility requirements, and application instructions can be found on the Funding Opportunity Exchange website under Reference Number DE-FOA-0000686.
The Energy Department’s Office of Energy Efficiency and Renewable Energy (EERE) accelerates development and facilitates deployment of energy efficiency and renewable energy technologies and market-based solutions that strengthen U.S. energy security, environmental quality, and economic vitality. Learn more about EERE’s work with industry, academia, and National Laboratory partners on a balanced portfolio of research in biomass feedstocks and conversion technologies.
CCRES ALGAE 
project of 
CROATIAN CENTER of RENEWABLE ENERGY SOURCES (CCRES)
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CCRES ALGAE

  •  CCRES ALGAE
  • Algae represent the third generation feedstock for biodiesel, with much higher yields than second generation crops. Algae yields could reach a high of 50 T of biodiesel per hectare year against 2 T for competing feedstock such as Jatropha.
  • While biodiesel is the fuel end product that is pursued most, algae can be processed to yield other energy products such as ethanol, diesel, gasoline, aviation fuel, hydrogen and other hydrocarbons. Some companies have started exploring production of these products as well.
  • Upstream processes such as strain selection, cultivation and harvesting present challenges that are unique to the algae industry and hence deserve closer attention.
  • Microalgae, owing to their relatively high oil content can be a feedstock for biodiesel while macroalgae is a potential feedstock for ethanol.
  • From over 30,000 strains of algae available, selecting the most suitable strain needs evaluation of parameters such as desired end products, oil/energy yields, performance in mass culture, complexity of structure, culturing media/environment and more.
  • In harsh environments such as deserts, photobioreactors might be the most suitable method to grow algae, owing to the control they offer on the external elements.
  • Costs of setting up and operating a photobioreactor for algae cultivation would be much higher than open ponds, but photobioreactors provide higher efficiency and oil yields. While open ponds costs about $100,000 per hectare in capital costs, photobioreactors cost about $1-$1.5 million per hectare – ten times as much as open pond! On the other hand, photobioreactors provide much higher control for algal monocultures and provide yields that are 3-5X those for open ponds.
  • Currently, photobioreactor costs range between $70-150/m2. Some of the most important research efforts currently being undertaken are for reducing the capital and operational costs for photobioreactors.
  • Ensuring high yield, providing optimal light penetration and cost effective aeration are some of the key challenges in microalgae cultivation.
  • In order to benefit from the advantages of photobioreactors and open ponds, some companies are exploring a hybrid cultivation system that uses both open ponds and PBRs.
  • Key challenges for cultivating microalgae in wastewater include the availability of large amounts of wastewater, prevention of contamination of desired strains, and cost-effective harvesting.
  • Photobioreactors might be the most suitable system to grow algae in deserts, owing to control they offer on the harsh environment present in the region.
  • Algae are already being cultivated in oceans for non-fuel end products such as cosmetics, medicines and food additives.
  • Using freshwater for algae cultivation is likely to be more expensive than using wastewater or salt water, as large quantities of freshwater might not so easily accessible, and nutrient credits might not be applicable for cultivation in fresh water.
  • While algae-based CO2 capture at power plants has excellent innate potential, such an activity is not expected to become commercialized until 2015.
  • Key challenges to this include large land requirements next to power plants, inefficiencies in the actual CO2 capture process and high costs of cultivation should photobioreactors be used.
  • Oilgae estimates that the current production costs for algae based biodiesel is about $18 per gallon if photobioreactors were used.
  • Companies that have come up with unique concepts for algae biofuels include Algenol, AlgoDyne, Blue Marble Energy, Inventure, Sapphire Energy and Solazyme.
  • As of Mar 2010, there are about 100 companies worldwide that have a focus on algae fuels.
  • While there are no dominant designs in the industry, there are entry barriers in the form of large financing requirements and the need for high end scientific expertise.
  • There could be some challenges faced while converting algae oil into biodiesel using the transesterification process, owing to the high Free Fatty Acid (FFA) content of algae oil.
  • Prominent methods currently used for harvesting microalgae are filtration, centrifugation, and flocculation.
    • Centrifugation and flocculation are expensive harvesting methods, but these are expected to have the most potential in future for harvesting microalgae.
    • The operational cost of centrifugation for algae harvesting varies from $100 to $500 per ton of algae biomass.
  • Companies are trying to overcome the challenges faced by the open pond system such as contamination, light penetration and water evaporation by using a hybrid algae product system – cross between open and closed system. For instance, the company GreenStar has introduced a hybrid of open-air and closed bioreactor system that combines the controlled environment of a closed photobioreactor with the inexpensive construction of an open pond system.
  • Algae in Bioremediation – Significant efforts are being undertaken for the use of algae in waste water treatment, and as a source of carbon capture from power plants, cement factories etc.
    • Research is going on with regard to harvesting microalgae growing in sewage and industrial wastewater. Dissolved air flotation and filtration have shown promise in the research done so far.
    • For power plants and other entities that are large scale emitters of CO2, sequestering CO2 using algae provides the opportunity of monetization through carbon credits while at the same time producing biofuels.
  • About 100 companies are pursuing the production of fuels from algae. Pilot projects undertaken by some of these companies suggest that algae could provide over 10,000 gallons of biodiesel per hectare per year.
  • Algae – both microalgae and macroalgae – have non-fuel applications that cover diverse industries. The food, health products and nutraceutical markets are the largest among these.
  • Prominent industries that have synergetic benefits from producing algae fuels are industries that either produce waste water or deal with treatment, power plants and cement plants that are large emitters of CO2, companies in the agriculture industry, poultry & cattle industry, and existing producers of non-fuel algae products such as nutraceuticals or animal feed.
  • The global biodiesel industry is projected to grow and touch around 14.4 billion gallons by 2015, from 5 billion gallons in 2009.
  • Venture capitalists are fully aware that algae energy is a high risk- high return domain, and that only companies that are willing to take big efforts to solve the problem have a chance of winning. Hence, they look for companies and teams that are trying to solve the problem by thinking big.
  • CCRES ALGAE project of CROATIAN CENTER of RENEWABLE ENERGY SOURCES (CCRES)
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Using algae for reducing the CO2

 

 

Algae live on a high concentration of carbon dioxide and nitrogen dioxide.  These pollutants are released by automobiles, cement plants, breweries, fertilizer plants, steel plants. These pollutants can serve as nutrients for the algae.

 

When fuels are burned there remains, besides ash, a certain number of gas components. If these still contain combustion heat, they are called heating gases. As soon as they have conveyed their energy to the absorbing surfaces of a heat exchanger, they are called flue or stack gases.

It further contains a small percentage of pollutants such as particulate matter, carbon monoxide, nitrogen oxides and sulfur oxides.

Carbon dioxide (CO2)

—the primary greenhouse gas responsible for global warming—along with other pollutants.
Its composition depends on what is being burned, but it usually consists of mostly nitrogen (typically more than two-thirds) derived from the combustion air, carbon dioxide (CO2) and water vapor as well as excess oxygen (also derived from the combustion air).

Using algae for reducing the CO2 concentration in the atmosphere is known as algae-based Carbon Capture technology. The algae production facilities can thus be fed with the exhaust gases from these plants to significantly increase the algal productivity and clean up the air.  An additional benefit from this technology is that the oil found in algae can be processed into a biodiesel. Remaining components of the algae can be used to make other products, including Ethanol and livestock feed.

This technology offers a safe and sustainable solution to the problems associated with global warming.

CCRES SPIRULINA

project of

Croatian Center of Renewable Energy Sources (CCRES)

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Cultivation of Algae

Cultivation of microalgae can be done in open systems (lakes, ponds) and in controlled closed systems called photo-bioreactors (PBR).

Open cultivation systems use ponds or lakes with added mechanical equipment to grow microalgae. Open ponds were the first cultivation technology for mass cultivation of microalgae. In this system water levels are kept no less than 15 cm, and algae are cultured under conditions identical to their natural environment. The pond is designed in a raceway configuration, in which a paddlewheel circulates and mixes the algal cells and nutrients.

Open cultivation system for growing algae

The raceways are typically made from poured concrete or they are simply dug into the earth and lined with a plastic liner to prevent the ground from soaking up the liquid. Baffles in the channel guide the flow around the bends in order to minimize space. The system is often operated in a continuous mode, where the fresh feed (containing nutrients including nitrogen phosphorus and inorganic salts) is added in front of the paddlewheel, and algal broth is harvested behind the paddlewheel after it has circulated through the loop. Depending on the nutrients required by algal species, several sources of wastewater can be used for algal culture. For some marine-type microalgae, seawater or water with high salinity can be used.

Raceway ponds growing algae

Although open ponds cost less to build and operate than closed systems using PBRs, this culture system has its disadvantages. The ponds can be built on any type of land but need large land areas for considerable biomass yield. Because they are in the open air, the water levels are affected from evaporation and rainfall. Natural CO2 levels in the atmosphere (0.03%-0.06%) are not enough for continuous mass growth of microalgae. Biomass productivity is also limited by contamination with unwanted algal species, organisms that feed on algae or other poisonous particles. Only few species can be grown in normal conditions.
Other types of construction use: 1) circular ponds where circulation is provided by rotating arms; 2) inclined systems where mixing is achieved through pumping and gravity flow.

Closed cultivation systems use PBRs – containers made of transparent materials for optimised light exposure. Enclosed PBRs have been employed to overcome the contamination and evaporation problems encountered in open systems. These systems are generally placed outdoors for illumination by natural light. The cultivation vessels have a large surface area-to-volume ratio. The most widely used PBR is a tubular design, which has a number of clear transparent tubes, usually aligned with the sun’s rays. The tubes are generally less than 10 centimeters in diameter to maximize sunlight penetration. The medium broth is circulated through a pump to the tubes, where it is exposed to light for photosynthesis, and then back to a reservoir. A portion of the algae is usually harvested after it passes through the solar collection tubes, making continuous algal culture possible.

In some PBRs, the tubes are coiled spirals to form what is known as a helical-tubular PBR. These systems sometimes require artificial light for energy, which adds to production costs.  Either a mechanical pump or an airlift pump maintain a highly turbulent flow within the reactor, which prevents the algal biomass from settling. The photosynthesis process generates oxygen. In an open raceway system, this is not a problem as the oxygen is simply returned to the atmosphere. In closed PBRS, the oxygen levels will build up until they inhibit and poison the algae. The culture must periodically be returned to a degassing zone—an area where the algal broth is bubbled with air to remove the excess oxygen. Also, the algae use CO2, which can cause carbon starvation and an increase in pH. Therefore, CO2 must be fed into the system in order to successfully cultivate the microalgae on a large scale.
PBRs require cooling during daylight hours, and the temperature must be regulated at night as well. This may be done through heat exchangers located either in the tubes themselves or in the degassing column.
The advantages of enclosed PBRs are obvious. They can overcome the problems of contamination and evaporation encountered in open systems. The biomass productivity of PBRs can average 16 times more than that of a traditional raceway pond. Harvest of biomass from PBRs is less expensive than from raceway ponds, because the typical algal biomass is about 30 times as concentrated as the biomass found in raceways. Controlled conditions in closed systems are suitable for genetic modification of algae cells and enable cultivation of better quality species (e.g. microalgae with higher oil content).
However, closed systems also have disadvantages. Technological challenges with PBRs are: overheating, bio-fouling, oxygen accumulation, difficulty in scaling up, cell damage by shear stress & deterioration and expensive building & maintenance. Light limitation cannot be entirely overcome because light penetration is inversely proportional to the cell concentration. Attachment of cells to the tubes’ walls may also prevent light penetration. Although enclosed systems can enhance biomass concentration, the growth of microalgae is still suboptimal due to variations in temperature and light intensity.
R&D in algae biotechnologies focus on developing innovative PBR designs and materials. Different developed designs are: serpentine, manifold, helical and flat containers. From these elevated reactors can be oriented and tilted at different angles and can use diffuse and reflected (artificial) light for growth. More specific information is available in PBRs section.
After growing in open ponds or PBRs, the microalgae biomass needs to be harvested for further processing. The commonly used harvest method is through gravity settlement or centrifuge. The oil from the biomass is extracted through solvent and further processed into biodiesel.

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