A small introduction on Bioenergy and Algae

High oil prices, global warming, and emphasis in renewable technology are attracting new interest in a potentially rich source of biofuels: algae. Currently, no alternative technology seems to be able to entirely replace our vast energy demands. Yet, we need new technologies to provide us the energy we need. One of these technologies which is recieving more and more attention is bioenergy derived from algae.

Microalgae can contain up to 40% oil, they can grow in wastewater and in live places where no agriculture is possible. They are able to grow very fast and they even capture large amounts carbon dioxide while doing so. These facts look very promising for use of algae in bioenergy, but can these algae really deliver?

Currently I am researching the integration of solar energy via algae into methane and electricity. The aim of the thesis is to research and develop the potential use of microalgal biomass for conversion into bioenergy.

So, how does this work? The algae are grown in salt water ponds in our laboratories. The algae convert carbon dioxide with energy from solar radiation into biomass, a process which is called photosynthesis. After they reach a certain density, an amount of water containing algae is put into an anaerobic digestor for 20 days. In this digestor, which is basically an airtight container with an microbial inoculum, the biomass of the algae is converted into biogas (65% methane, the rest is carbon dioxide). This digestor is built in a way that no air comes in, but the biogas is being captured for analysis. Theoretically, it should generate ~0,5 l biogas per gram dry algae.

Microbial Fuel CellWhen the algal fluid is digested, it is transferred into an Microbial Fuel Cell (as seen left), which is a sort of bio battery. The main goal of the microbial fuel cell is to generate electricity while further degrading the effluent of the digestor. It contains two 165 ml compartments seperated by a membrane. One compartment contains the digested fluid and an active microbial mat which converts the organic material, the other contains water with dissolved oxygen. Organic compounds are metabolised by bacteria in the first compartment, and the electrons are transferred via the electrode to the other compartment, where they are taken up by oxygen and form water. This current can be used as electricity.

Microbial fuels should generate a potential about 100 mV or more and some current. After the fluid has passed through the microbial fuel cell, it is poured into the ponds to the algae can grow again.

Microbial Fuel Cell

Figure: scheme of a microbial fuel cell. In the left compartment, substrate is oxidized. Electrons transfer to the other compartiment and react with oxygen.

Now you know something about the general principles of this research. This work is just a tiny addition in the rapidly growing algal to bioenergy field. Converting algae to biogas and electricity is not the only possible application for algae. Other projects on algae involve the use of algae in reducing carbon dioxide emissions from energy plants (MIT – USA). Some companies use algae to produce omega-3 (SBAE – Belgium) fatty acids or pharmaceuticals. Some grow algae strains with high oil contents in order to produce biodiesel (AlgaeLink – Netherlands, Shell/Cellana – Hawaii). Many other projects worldwide are currently researching algal production for bioenergy creation.

In the coming months I’ll regularly post updates on the progress of these potentially vital researchs.

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7 Responses to “A small introduction on Bioenergy and Algae”

  1. Pudji Says:

    Dear Mr.Jan Vanhoute
    My name is Pudji Santoso, I’m from Indonesia. I have been working in algae cultivation during 5 years in ones marine research center. I’m intersting about your new concept in algal production [ after i was read in aquaculture asia pacific magazine].

  2. Prof.Hans-Jürgen Franke & Prof. Pengcheng Fu Says:

    ETHANOL-PRODUCTION WITH BLUE-GREEN-ALGAE
    A SOLUTION AFTER PEAK-OIL AND OIL-CRASH

    University of Hawai’i Professor Pengchen “Patrick” Fu developed an innovative technology, to produce high amounts of ethanol with modified cyanobacterias, as a new feedstock for ethanol, without entering in conflict with the food and feed-production .

    Fu has developed strains of cyanobacteria — one of the components of pond scum — that feed on atmospheric carbon dioxide, and produce ethanol as a waste product.

    He has done it both in his laboratory under fluorescent light and with sunlight on the roof of his building. Sunlight works better, he said.

    It has a lot of appeal and potential. Turning waste into something useful is a good thing. And the blue-green-algae needs only sun and wast- recycled from the sugar-cane-industry, to grow and to produce directly more and more ethanol. With this solution, the sugarcane-based ethanol-industry in Brazil and other tropical regions will get a second way, to produce more biocombustible for the worldmarket.

    The technique may need adjusting to increase how much ethanol it yields, but it may be a new technology-challenge in the near future.

    The process was patented by Fu and UH in January, but there’s still plenty of work to do to bring it to a commercial level. The team of Fu foundet just the start-up LA WAHIE BIOTECH INC. with headquarter in Hawaii and branch-office in Brazil.

    PLAN FOR AN EXPERIMENTAL ETHANOL PLANT

    Fu figures his team is two to three years from being able to build a full-scale
    ethanol plant, and they are looking for investors or industry-partners (jointventure).

    He is fine-tuning his research to find different strains of blue-green algae that will produce even more ethanol, and that are more tolerant of high levels of ethanol. The system permits, to “harvest” continuously ethanol – using a membrane-system- and to pump than the blue-green-algae-solution in the Photo-Bio-Reactor again.

    Fu started out in chemical engineering, and then began the study of biology. He has studied in China, Australia, Japan and the United States, and came to UH in 2002 after a stint as scientist for a private company in California.

    He is working also with NASA on the potential of cyanobacteria in future lunar and Mars colonization, and is also proceeding to take his ethanol technology into the marketplace. A business plan using his system, under the name La Wahie Biotech, won third place — and a $5,000 award — in the Business Plan Competition at UH’s Shidler College of Business.
    Daniel Dean and Donavan Kealoha, both UH law and business students, are Fu’s partners. So they are in the process of turning the business plan into an operating business.

    The production of ethanol for fuel is one of the nation’s and the world’s major initiatives, partly because its production takes as much carbon out of the atmosphere as it dumps into the atmosphere. That’s different from fossil fuels such as oil and coal, which take stored carbon out of the ground and release it into the atmosphere, for a net increase in greenhouse gas.
    Most current and planned ethanol production methods depend on farming, and in the case of corn and sugar, take food crops and divert them into energy.

    Fu said crop-based ethanol production is slow and resource-costly. He decided to work with cyanobacteria, some of which convert sunlight and carbon dioxide into their own food and release oxygen as a waste product.

    Other scientists also are researching using cyanobacteria to make ethanol, using different strains, but Fu’s technique is unique, he said. He inserted genetic material into one type of freshwater cyanobacterium, causing it to produce ethanol as its waste product. It works, and is an amazingly efficient system.

    The technology is fairly simple. It involves a photobioreactor, which is a
    fancy term for a clear glass or plastic container full of something alive, in which light promotes a biological reaction. Carbon dioxide gas is bubbled through the green mixture of water and cyanobacteria. The liquid is then passed through a specialized membrane that removes the
    ethanol, allowing the water, nutrients and cyanobacteria to return to the
    photobioreactor.

    Solar energy drives the conversion of the carbon dioxide into ethanol. The partner of Prof. Fu in Brazil in the branch-office of La Wahie Biotech Inc. in Aracaju – Prof. Hans-Jürgen Franke – is developing a low-cost photo-bio-reactor-system. Prof. Franke want´s soon creat a pilot-project with Prof. Fu in Brazil.

    The benefit over other techniques of producing ethanol is that this is simple and quick—taking days rather than the months required to grow crops that can be converted to ethanol.

    La Wahie Biotech Inc. believes it can be done for significantly less than the cost of gasoline and also less than the cost of ethanol produced through conventional methods.

    Also, this system is not a net producer of carbon dioxide: Carbon dioxide released into the environment when ethanol is burned has been withdrawn from the environment during ethanol production. To get the carbon dioxide it needs, the system could even pull the gas out of the emissions of power plants or other carbon dioxide producers. That would prevent carbon dioxide release into the atmosphere, where it has been implicated as a
    major cause of global warming.
    Honolulo – Hawaii/USA and Aracaju – Sergipe/Brasil – 15/09/2008

    Prof. Pengcheng Fu – E-Mail: pengchen2008@gmail.com
    Prof. Hans-Jürgen Franke – E-Mail: lawahiebiotech.brasil@gmail.com

    Tel.: 00-55-79-3243-2209

  3. mr.khani Says:

    Dear Sir
    Hello
    I am managing director of a company called ‘Mehr Pakhsh.
    We are planning to produce Bio diesel , using alga oil. Nice to know that until now there has been no one working on alga production in an industrial way and oil extraction of that in IRAN.
    I have visited your web site and have some questions
    1- if you have any interest to have a representative in IRAN?
    2- if yes, under which situation?
    It will be great if you will answer as soon as possible.

    Best regards

    Roohollah Khani

  4. Ghost Says:

    Dear mr jan vanhoute ive grown algae for a while now but i am not sure if they need oxygen or carbon dioxide and they seem to produce a gas but i don’t know if its methane or another gas product and can any algae produce methane ? ? I know only of 4 kinds of methane producing algae please help . Dirk van zyl from south africa

  5. Robert Ware Says:

    In this posting the grwoth rate of algae is refered to in terms of area, as if it were a terrestrial crop. But it is an aquatic crop, grows in water and when referring to water you must speak in volume. The proper way to refer to algae growth rater is per unit volume which is cubic meters, feet, inches, gallons, liters, acre foot or any other volumetric unit you wish to use; not in square meters, foot, inches, yards, miles, acres or any other unit of area.

    How learned people can be so dense is beyond me.

  6. Robert Ware Says:

    pardon me, grwoth should be spelled growth

  7. harini Says:

    Dear Mr. Jan
    I am working on Microbial fuel cells.In ur work description u have mentioned tat u have used algae in the anode compartment of Microbial fuel cell.How about using it in the cathode compartment? give me some ideas.

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