CCRES Low Carbon Fuels in Aviation

 photo by CCRES

Biofuels are key to industry’s future

 In a bid to reduce its dependency on imported oil and tackle global warming, the EU has committed to raising the share of fuels from renewable sources in transport to 10% by 2020 – including biofuels, hydrogen and green electricity.

For the growing aviation industry, the switch to plant-based fuel is seen as not only environmentally smart, but a sensible financial move in an era or rising conventional fuel prices and worries about supply security.

Biofuel use in passenger aircraft is still a novelty, and industry officials are urging governments to help lift supplies, much as policies in the EU and United States have created a flourishing market in plant-based oils for motor vehicles.

The industry contends that sustainable fuels will reduce emissions even as passenger traffic grows. The airline sector has committed to meet 10% of its overall fuel consumption with biofuels by 2017 – though the goal is ambitious given that it is to account for just 1% by 2015...

Meanwhile, more doubts are being raised about the environmental benefits of biofuels.

The United Nations Environment Programme has warned that even though burning plant-based fuels can produce significantly lower levels of carbon emissions, production and land clearing to make way for new crops “may reduce carbon-savings or even lead to an increase.”

European conservation groups say the EU and European governments should wait to embrace aviation biofuels until there is proof of their environmental benefits.

 ”Given the right conditions, algae can double its volume overnight. Microalgae are the earth’s most productive plants –– 10 to 15 times more prolific in biomass than the fastest growing land plant exploited for biofuel production. While soy produces some 50 gallons of oil per acre per year; canola, 150 gallons; and palm, 650 gallons, algae can produce up to 15,000 gallons per acre per year. In addition, up to 50 percent (or more) of algae biomass (dry weight) is comprised of oil, whereas oil-palm trees—currently the most efficient large-scale source of feedstock oil to make biofuels—yield approximately 20 percent of their weight in oil,” says Zeljko Serdar, President of CCRES

 Airlines have committed to ramping up their use of biofuels in the belief that they can contribute to achieving the sector's pledges on carbon-neutral growth. For 2050, the EU foresees 40% use of "sustainable low carbon fuels" in aviation.

Croatian Center of Renewable Energy Sources (CCRES)

SPIRULINA

photo         by       CCRES      SPIRULINA 

Spirulina   is simply  the  world’s most  digestible  natural  source  of  high quality  protein,  far  surpassing the  protein bio availability of even beef  ( which  most  people  consider  to  be  th e  #1 source of  protein ). The  digestive  absorption  o f  each  gram  of  protein  in  spirulina  is  four  times  greater  than  the  same  gram  of   protein   in   beef.  And   since   spirulina   already   contains   three   times   more   protein  ( by  weight )  to   begin   with,   the   net result is   that  , ounce   for   ounce, spirulina   offers   twelve   times   more  digestible   protein     than   beef. 

That’s   an astounding   difference.  

  

photo         by       CCRES      SPIRULINA 

 It   means    that   spirulina   is   the   ideal  food  source   for   people   working  to  get   more  protein   into  their diets : 

•  People on low-carb, high-protein diets.

• People who exercise vigorously or engage in strength training. 

• People who are frail, who have trouble gaining weight, or who are malnourished. 

 

photo         by       CCRES      SPIRULINA 

In   fact,   there’s   probably   no  better single food  source  on  the  planet  than  spirulina  for  these  people.  The  protein   found   in  spirulina   is  also   a complete  protein,  meaning   that   it  contains  all eight  essential   amino acids, unlike  beans, whole   grains   and other  plant- based   foods   that   typically   lack  one  or  more  amino acids.

  

pho         to by       CCRES      SPIRULINA 

CCRES ALGAE PROJECT

 part of 

Croatian Center of Renewable Energy Sources (CCRES)

CCRES Algae Project Q&A

 CCRES ALGAE

CCRES Algae Project
Q&A

See answers to common questions about growing algae for biofuel production.

    Algae’s potential
    What makes algae a better alternative fuel feedstock than cellulosic feedstocks, such as switchgrass or miscanthus?
    What transportation fuels can algae produce?
    How much fuel can algae produce?
    Where could this type of algae grow?
    What can you do with material derived from algae production not used for fuel?

    Economics
    How much would a gallon of algae-based transportation fuel cost if it were available at a service station today?
    What can accelerate the commercial availability of algae biofuel?

    Environment
    How will algae-based transportation fuels impact greenhouse gas emissions?
    Is the process capable of being replicated at the local level to increase energy efficiency and promote low-energy overhead?

    Security
    Can algae-based fuels be used in developing countries to help them bypass fossil fuel dependence?

CCRES ALGAE

Q: What makes algae a better alternative fuel feedstock than cellulosic feedstocks, such as switchgrass or miscanthus?

    A: Large-scale production of resource-intensive plants, like switchgrass or miscanthus, requires a substantial amount of fertile land, fresh water, and petroleum-based fertilizer to grow. The fuel derived is ethanol, a lower-energy fuel not compatible with the infrastructure now used to transport, refine, and deliver liquid fuels, like gasoline and diesel.

    Conversely, algae can produce hydrocarbons capable of being converted directly into actual gasoline or diesel fuel, which can be transported and delivered to market using the existing refinery infrastructure.


Q: What transportation fuels can algae produce?
    A: Algae produce a variety of fuel and fuel precursor molecules, including triglycerides and fatty acids that can be converted to biodiesel, as well as lipids and isoprenoids that can be directly converted to actual gasoline and traditional diesel fuel. Algae can also be used to produce hydrogen or biomass, which can then be digested into methane.

Q: How much fuel can algae produce?

    A: The United States consumes 140 billion gallons per year of liquid fuel. Algae can produce 3,000 gallons of liquid fuel per acre in a year, so it would take 45 million acres of algae to provide 100% of our liquid fuel requirements.

    For comparison, in 2008 the United States had 90 million acres of corn and 67 million acres of soybeans in production. So growing 45 million acres of algae, while challenging, is certainly possible.


Q: Where could this type of algae grow?

    A: Algae perform best under consistent warm temperatures between 20 and 30 degrees. Climates with plenty of sunshine offer optimal conditions. Ideal Croatian locations include many of the southern and southwestern areas, such as Dalmatia,(including Dalmatian hinterland ).

CCRES ALGAE

 
Q: What can you do with material derived from algae production not used for fuel?

    A: Production of 140 billion gallons of fuel from algae would also yield about 1 trillion pounds of protein. Since algae-produced protein is very high quality, this protein could be used to feed livestock, chicken, or fish. Presently, all livestock in this country consume about 770 billion pounds of protein per year.


Q: How much would a gallon of algae-based transportation fuel cost if it were available at a service station today?

    A: Today, the cost would be relatively expensive. Additional investment in research is needed to further refine and enhance the algae strains that generate such fuels. Also, more infrastructure needs to be developed to achieve the necessary economies of scale that will come with large-scale commercial production. Once overall efficiency increases, the cost of producing a gallon of gasoline from algae will dramatically reduce.


Q: What can accelerate the commercial availability of algae biofuel?

    A: As viable and potentially transformational as algae-based transportation fuels have already proven, we need a much better knowledge base on algae at the microbial level. We also need to build on this platform to develop the tools and train the next generation of scientists that will help usher in the age of accessible, affordable, and sustainable fuels made from algae. That is a central component of the Croatian Center for Algae Biofuels (CCRES Algae Project).

CCRES ALGAE

Q: How will algae-based transportation fuels impact greenhouse gas emissions?

    A: Production of alternative transportation fuels from algae will help reduce the amount of CO2 in the environment. Algae provide a carbon-neutral fuel because they consume more CO2 than is ultimately released into the atmosphere when algae-based fuel burns. The amount of carbon removed from the environment will depend on the number of algae farms built and the efficiency with which algae can be modified to convert CO2 to fuel products. Eventually, algae farms will likely be located adjacent to CO2 producing facilities, like power plants, resulting in potentially significant CO2 sequestration benefits.


Q: Is the process capable of being replicated at the local level to increase energy efficiency and promote low-energy overhead?

    A: Absolutely. There are huge advantages to locating algae farms near urban centers. The algae consume industrial waste and contaminants, which are usually found in higher concentrations near cities. A perfect location is near a power plant, where the algae can consume flue gas and other waste, or near a wastewater treatment plant where the algae could consume significant amounts of nitrates and phosphates from the waste stream. This could result in cleaner effluent discharge, and perhaps eventually create “new” sources of non-potable water for industrial or agricultural use.


Q: Could algae-based fuels be used in developing countries to help them bypass fossil fuel dependence?

    A: Algae-based fuels (and the protein byproducts derived from their production) definitely have the potential to positively impact developing countries. The requirements for farming algae are fairly straightforward and can be done almost anywhere in the world with an adequate supply of sunshine. In Africa, for example, millions of algae acres could be farmed in its less-populated regions, resulting in a reduced dependence on foreign oil and a reliable and sustainable energy supply.

 

CCRES ALGAE PROJECT

part of 

Croatian Center of Renewable Energy Sources (CCRES)

Carbon capture and consumption

 

Could it Eliminate the Need for Wastewater Aeration?

Algal blooms have always proved a challenge for the water industry. Yet could this organic matter,with the help of wastewater nutrients, be turned into a biofuel and help alleviate fossil fuel shortages? Tom Freyberg investigates the European funded All-Gas project.

First generation biofuels from crops never really bloomed into a fruitful harvest. Opponents criticized using up valuable land to grow crops and fuel the cars of the rich, instead of filling the stomachs of the poor. Second generation biofuels – made from biomass - have proved a lot harder to extract the required fuel and fully crack.

And then along came algae. Unlike first generation biofuels, algae can be grown using land and water not suitable for plant and food production.

Consuming solar energy and reproducing itself, algae generates a type of oil that has a similar molecular structure to petroleum products produced today. As if this wasn't enough – algae growth also consumes carbon dioxide, a known major greenhouse gas (GHG).

As a result of the apparent benefits the race is on to commercialize second and now third generation biofuels, in the case of algae. Continents and companies are putting money where their mouths are to find out how what we thought was simply a green weed growing in the sea could be the answer to inevitable fossil fuel shortages.

Algal culture ponds are used to grow and harvest micro-algae using nutrients contained in wastewater

Earlier this year US President Barack Obama announced that the Department of Energy would make $14 million available to support research and development into biofuels from algae. The Department has suggested that up to 17% of the US' imported oil for transportation could be replaced with biofuels derived from the substance.

Meanwhile Europe is going even further and mandating the gradual replacement of fossil fuels to biofuels. An EU Directive stipulates that by 2020 a total of 20% of energy needs should be produced by renewable fuels. A further requirement is that 10% of biofuels need to be met through transport related activities.

Even UK government backed agency the Carbon Trust has forecast that by 2030, algae-based biofuels could replace more than 70 billion litres of fossil fuels used every year around the world in road transportation and aviation.

Nutrients: burden or blessing?

So far, so good. Yet while algae derived biofuels sound like an answer to inevitable fossil fuel shortages, two challenges remain: space and nutrients. The first challenge will be addressed later but on the topic of nutrients, phosphorous and ammonia are required alongside sun light and carbon dioxide to "feed" the algae. And with up to 30% of operating costs at algae farms attributed to buying and adding in such nutrients, it's a notable expense.

It is in response to this particular challenge where the wastewater sector could play its part, with untreated effluent being a known source of phosphorous and other nutrients. An EU funded project aims to bring together the challenge and solution and link the water and biofuel industries together.

The €12 million, five-year project is starting at water management company aqualia's wastewater treatment plant in Chiclana, Southern Spain and is backed by the European Union as part of its FP7 program – supporting energy-related projects - with six partners.

Called All-Gas, which translates into algae in Spanish, the project will see "algal culture ponds" being used to grow micro-algae using nutrients contained in wastewater, such as phosphorous. A 10-hectare site will eventually be needed for the project. Frank Rogalla, head of R&D at aqualia, says nutrients are abundant in wastewater, so it makes sense to incorporate the two industries.

Traditionally aeration processes at wastewater treatment plants are heavy energy users, accounting for up to 30% of a facility's operating costs. In the US, according to the Environmental Protection Agency, drinking water and wastewater systems account for between 3% and 4% of national energy consumption alone.

However, Rogalla later told Water & Wastewater International magazine (WWi) that growing algae with wastewater can eliminate the need for aeration, thus reducing energy use.

He said: "We have converted our treatment to anaeraobic pre-treatment, meaning we will generate biogas from the start instead of destroying organic matter, so no aeration will be needed. From the 0.5 kWh [kilowatt-hour] per m³ which you generally spend for aeration, that will be completely gone. We will have a net output of energy from algae conversion either to oils or to gas. So that's why you get this positive output of 0.4 kWh per m³ of wastewater treated."

Rogalla added: "It will not cost more than traditional wastewater treatment, which costs about 0.2 Euros per cubic metre. We think we will use the same operational costs but instead of consuming energy we will produce additional benefit, meaning we generate about 0.2 Euros per cubic metre in additional profit from the fuel. Our aim is to be cost neutral."

So the question has to be asked of how, technically, can the proposed treatment eliminate the need for wastewater aeration? The answer, as Rogalla later tells WWi, is through the initial conversion to biogas.

Compared to nitrification and dentrification to eliminate nutrients in conventional wastewater treatment, a process Rogalla says consumes about 5 kWh/kg Nitrogen during aeration, All-Gas will use an alternative conversion. Firstly anaerobic pre-treatment will convert most organic matter into biogas (CH4 and CO₂). Algae will then take up the nitrogen and phosphorous.

Productive: instead of using traditional nitrification and dentrification processes, organic matter will instead be converted into biogas

As the algae will transform most nutrients into biomass, they will also produce O2 in the process, as CO₂ is taken up and oxygen released in their metabolic process. As a result, according to Rogalla, aeration is not necessary. Most organic carbon is transformed into energy (via biogas), nutrients are incorporated into algae, which produce oxygen for any polishing action necessary.

An overview of aqualia's wastewater treatment plant in Chiclana, Southern Spain

"It only seems logical to use the wastewater nutrients to grow algae biomass; on the one hand saving the aeration energy, on the other hand the algae fertilizer and cleaning wastewater without the occurrence of useless sludge, but producing biofuels and added value instead," Rogalla adds.

CROATIAN CENTER of RENEWABLE ENERGY SOURCES (CCRES)

  special thanks to U.S. Department of Energy | USA.gov

  and WaterWorld, Industrial WaterWorld

Space challenges

Addressing the second challenge of space requirements to harness algae ponds, for a commercial scale operation it's estimated that a 10 hectare site is required (roughly 10 football pitches). Yet when compared to the oil yields of other crops, algae still proves favourable.

Data from US-based National Renewable Energy Laboratory (NREL) show that oil yields from soybeans work out at 400 litres/hectare/year, which compares to 6,000 for palm oil and theoretically, a potential 60,000 for microalgae. For barrels/hectare/year, the same comparison yields 2.5 for soybeans, 36 for palm oil and a minimum of 360 for microalgae.

As predictions go, the production of 60,000 litres of biofuel from only one hectare of algae is optimistic compared aqualia's aims for the Europe project. If a target set by the EU is reached, then each hectare should produce 20,000 litres of biodiesel. This, the firm says, compares to 5000 litres of biofuel per hectare per year for biofuels such as alcohol from sugar cane or biodiesel from palm oil.

The Spanish project also hopes to use produced biogas from the anaerobic pre-treatment and raw wastewater organic matter as car fuel, with each hectare touted to treat about 400 m³ per day.

Statistics to one side, the challenge of space remains. Booming urban populations are expanding closer to rural wastewater treatment plants but at the same communities insist on an 'out of sight, out of mind' rule when it comes to infrastructure that treats their waste. Rogalla does not think the land issue could impede the development of algae ponds to the majority of wastewater treatment plants. "Algae ponds of course can be put on marginal lands, or even on rooftops," he adds. "In rural areas extensive oxidation ponds for wastewater treatment are not uncommon, not to mention the often unused land areas as buffer zones around wastewater treatment plants.

Biogas generated from wastewater could mean the 0.5 kWh per m3 usually spent on aeration won't be required

"As we do not claim that all fuel can be made from biofuel on land, but only where possible wastewater should be turned into biofuel (excluding mostly big cities), the land issue seems secondary."

Carbon capture and consumption

One further benefit that has made algae growth attractive compared to other fuels is its consumption of Greenhouse Gases (GHG), namely CO₂, in order to grow. While captured carbon consumed by algae will inevitably be released later when used as a fuel in cars, it could still be a step in the right direction in reducing the impact of a world still firmly grasping CO₂ emitting fuel sources.

An article entitled Algal Biofuels: The Process from NREL in a Society for Biological Engineering journal suggests that over two billion tons of CO₂ could be captured by growing algae on the space equivalent to the entire U.S. soybean crop of 63.3 million acres.

Power plants and cement kilns appear to be an ideal match for algae growth, then. Yet, in order for All-Gas to attract seven million Euros worth of funding for its project, the CO₂ had to come from renewable sources. Any fossil fuel burning plants were not permitted, as Denise Green, manager of biofuels across Europe and Africa from Hart Energy Consulting tells WWi.

"This particular call was restricted to projects in which the carbon dioxide supply for the algae cultivation was provided by renewable applications, excluding carbon dioxide from fossil fuel installations," she says.

"However I see no reason why future funding for algae projects could not be provided for research into algae as part of the solution for CO₂ capture for zero emission power generation. If there are objections to using algae from fossil fuel installations for transportation fuels, there are other industries for which algae can be used where this may not be an issue."

Project roll out and commercialisation

The project will be implemented in two stages, with a prototype facility being used to confirm the scale of the full-size plant during the first two years. Once the concept has been proven in full-scale ponds, a 10 hectare site will be developed and operated at commercial scale during the next three years.

Rogalla suggests the project could be rolled out among aqualia's existing facilities along the Mediterranean belt, including Italy, Portugal, Egypt and even South America, all of which have "favourable conditions, meaning the climate is advantageous and the land is available".

Clearly, the conversion of algae to fuel is possible and has been demonstrated on a laboratory scale. It could hold the potential to turn a new leaf for biofuels haunted by their unsuccessful and much criticized first generation brothers. The real interest for the water sector should be the pipe dream of the project to eliminate aeration and turn existing wastewater treatment facilities into biofuel production centres.

The pivotal outcome of the project will be cost. This was proved in the well documented closure of the US Department of Energy's algae research programme in 1996 after nearly 20 years of work. At the time it was estimated that the $40-60/bbl cost of producing algal oil just couldn't compete with petroleum for the foreseeable future.

However, it is the additional methane extracted from raw wastewater and algae residue that differentiates this project. It's not just reliant upon biodiesel produced from the algae. All-Gas has the chance to spearhead Europe into proving that algae biofuel, through the help of wastewater, could eventually be more competitive on a per barrel price with traditional oil.

CCRES ALGAE PROJECT 

part of 

Croatian Center of Renewable Energy Sources (CCRES)

Way to Create Biofuels

Way to Create Biofuels

Is there a new path to biofuels hiding in a handful of dirt? 

Lawrence Berkeley National Laboratory (Berkeley Lab) biologist Steve Singer leads a group that wants to find out. They’re exploring whether a common soil bacterium can be engineered to produce liquid transportation fuels much more efficiently than the ways in which advanced biofuels are made today.

The scientists are working with a bacterium called Ralstonia eutropha. It naturally uses hydrogen as an energy source to convert CO2 into various organic compounds.

The group hopes to capitalize on the bacteria’s capabilities and tweak it to produce advanced biofuels that are drop-in replacements for diesel and jet fuel. The process would be powered only by hydrogen and electricity from renewable sources such as solar or wind.

The goal is a biofuel—or electrofuel, as this new approach is called—that doesn’t require photosynthesis.

Why is this important? Most methods used to produce advanced biofuels, such as from biomass and algae, rely on photosynthesis. But it turns out that photosynthesis isn’t very efficient when it comes to making biofuel. Energy is lost as photons from the sun are converted to stored chemical energy in a plant, which is then converted to a fuel.

“We’re after a more direct way,” says Singer, who holds appointments with Berkeley Lab’s Earth Sciences Division and with the Joint BioEnergy Institute (JBEI), a multi-institutional partnership led by Berkeley Lab.

“We want to bypass photosynthesis by using a microbe that uses hydrogen and electricity to convert CO2 into a fuel,” he adds.

Widespread use of electrofuels would also reduce demands for land, water, and fertilizer that are traditionally required to produce biofuels.

Berkeley Lab’s $3.4 million electrofuel project was funded in 2010 by DOE’s Advanced Research Projects Agency-Energy (ARPA-E) program, which focuses on “high risk, high payoff concepts—technologies promising genuine transformation in the ways we generate, store and utilize energy.”

That pretty much describes electrofuels. ARPA-E estimates the technology has the potential to be ten times more efficient than current biofuel production methods. But electrofuels are currently confined to lab-scale tests. A lot of obstacles must be overcome before you’ll see it at the pump.

Fortunately, research is underway. The Berkeley Lab project is one of thirteen electrofuel projects sponsored by ARPA-E. And earlier this year, ARPA-E issued a request for information focused on the commercialization of the technology.

Singer’s group includes scientists from Virginia-based Logos Technologies and the University of California at Berkeley. The project’s co-principal investigators are Harry Beller, Swapnil Chhabra, and Nathan Hillson, who are also with Berkeley Lab and JBEI; Chris Chang, a UC Berkeley chemist and a faculty scientist with Berkeley Lab’s Chemical Sciences Division; and Dan MacEachran of Logos Technologies.

The scientists chose to work with R. eutropha because the bacterium is well understood and it’s already used industrially to make bioplastics.

They’re creating engineered strains of the bacterium at JBEI, all aimed at improving its ability to produce hydrocarbons. This work involves re-routing metabolic pathways in the bacteria. It also involves adding pathways from other microorganisms, such as a pathway engineered in Escherichia coli to produce medium-chain methyl ketones, which are naturally occurring compounds that have cetane numbers similar to those of typical diesel fuel.

The group is also pursuing two parallel paths to further boost production.

In the first approach, Logos Technologies is developing a two-liter bioelectrochemical reactor, which is a conventional fermentation vessel fitted with electrodes. The vessel starts with a mixture of bacteria, CO2, and water. Electricity splits the water into oxygen and hydrogen. The bacteria then use energy from the hydrogen to wrest carbon from CO2 and convert it to hydrocarbons, which migrate to the water’s surface. The scientists hope to skim the first batch of biofuel from the bioreactor in about one year.

In the second approach, the scientists want to transform the bacteria into self-reliant, biofuel-making machines. With help from Chris Chang, they’re developing ways to tether electrocatalysts to the bacteria’s surface. These catalysts use electricity to generate hydrogen in the presence of water.

The idea is to give the bacteria the ability to produce much of their own energy source. If the approach works, the only ingredients the bacteria will need to produce biofuel would be CO2, electricity, and water.

The scientists are now developing ways to attach these catalysts to electrodes and to the surface of the bacteria.

“We’re at the proof-of-principle stage in many ways with this research, but the concept has a lot of potential, so we’re eager to see where we can take this,” says Singer.

CCRES

 special thanks to 

Lawrence Berkeley National Laboratory

Croatian Center of Renewable Energy Sources (CCRES)

CCRES - ALGAE BIOFUELS AND AQUAPONICS

 

CROATIAN CENTER of RENEWABLE ENERGY SOURCES 

(CCRES)

Algae, the Source of Biofuels, and Aquaponics

Algae can be used as important types of biomass materials from which the biofuels can be obtained. Algae absorb the energy from the sun in the presence of carbon dioxide and store it. A number of processes can be carried out on algae to convert it into biofuels like alcohol, biodiesel and even biogas. The biodiesel obtained from algae can be mixed with petroleum diesel and it can be used for running of trucks, cars and many types of engines that use diesel. Biodiesel can also be used as the fuel in the jets, airplanes, refineries and pipelines. The biomass obtained from algae can be used as the renewable sources of energy since it is available in abundant quantities and will be available for unlimited period of time.

One of the important advantages of algae is that it can grow in any type of water like salt, fresh, and even contaminated water. It can be grown in vast sea and river water, small rain water ponds and even commercial or domestic manmade made ponds. Algae has the potential to yield 30 times more energy than the crops grown on land, which are currently being used to produce the biofuels. This could encourage the use of algae for producing biofuels instead of the land that can be used for producing food crops. The harvesting cycle of algae is 1 to 10 days, which permits several harvests in short period of time and using the resources more effectively.

Algae and Aquaponics

As described earlier, algae can be grown in any type of water and in type of water storage system. Besides the naturally occurring seas, rivers, and ponds, it can also grow in manmade ponds. The manmade ponds can be at homes for domestic purpose or in large lands made for commercial production of algae. For the better growth of algae some nutrients may be added to water. Besides using these ponds for algae growth they can also be used for the growth of fishes and other aquatic animals.

Aquaponics is the system where one can grow the fishes and plants like algae in one integrated system. The waste given by the fishes act as important nutrients for the plants, while the cover of plants provides the natural filter for the fishes in the living areas. Aquaponics is the combination of words aquaculture and hydroponics. Aquaculture is the cultivation of fish or other water based animals, while hydroponics is the growth of plants in water. In aquaponics one can grow the water animals as well the plants at the same time. Thus the manmade small or big pond can be effectively used for growing fishes as well plants like algae.

The plants usually prefer warm-water so the water in aquaponics is also warm. The fishes grown in aquaponics are of warm-water type and not of cold-water type. The fishes grown in aquaponics can be consumed by the owner, they can be given to the friend, can be sold in the market to earn money or they can be kept as the pets. The harvesting period of fishes ranges from 7 to 9 months. When aquaponics is combined with a controlled environment greenhouse, high quality crops can be grown throughout the year and in any part of the world.

Aquaponics comprises of the water tank where the fishes are raised and fed. There is a chamber, where the uneaten foods and other particles and solids are collected. The bio-filter converts ammonia into nitrates, which act as the nutrients for the plants. There is also a portion for the growth of the plants. The lowest part of tank is a sump from where fresh water is supplied to the tank and old water is removed.

The concept of aquaponics can be extended for the growth of algae. Instead of the plants, one can grow algae, which has the harvest cycle of one to ten days. At the same time the fishes can also be grown. In the period of about nine months, while the fishes will harvest once, algae will be harvested several times. The large quantities of algae collected this way can be used as the biomass for producing the biofuels like biodiesel.

The advantages of using aquaponics for the growth of algae is that in a single place harvesting of both, the algae as well as fishes can be done. This would increase the profitability for the owner if they already have aquaculture or hydroponics. While earlier they would get only a single product from the infrastructure, they could now get two products. Since harvesting time of algae is short, it would keep the owner busy and this could become a continuous source of income for them.

The major limitations of aquaponics are the high initial costs required for housing, tank, plumbing, pumps and bedding. One should also do thorough research for the chances of success of such project. The system also has number of points of failure and requires intensive maintenance.

CCRES 

special thanks to   

Escapeartist, Inc

 CROATIAN CENTER of RENEWABLE ENERGY SOURCES 

(CCRES)