Posts Tagged algae

Algae Harvesting

Posted by on Sunday, 19 December, 2010

Algae is an alternative to petroleum based fuel. There are many companies that grow algae in large ponds, dry it out, and burn it, providing a source of renewable energy. Algae also grows in streams and rivers. If farms use a large amount of fertilizer, the runoff can make algae grow very rapidly, and the out of control algae growth can become a major problem that kills other wildlife and makes it difficult for ships to travel.

A Seattle based company, Blue Marble Energy, takes a different approach to algae harvesting than many of its competitors. Other firms only grow their own algae, Blue Marble Energy extracts algae from rivers in Washington. According to Seattle University, Blue Marble Energy harvested more than 4000 pounds of algae from Puget Sound. The state of Washington did not have to pay to store the algae in a landfill, and Blue Marble gained a large amount of material to make higher value petrochemicals.

Harvesting invasive algae avoids some of the major problems with biofuels. When energy producers use corn or another crop to produce ethanol, this uses up part of the food crop, which can lead to higher food costs. Growing biofuels can use up petroleum, because of the fertilizers and other products which are necessary to grow the crops.

The federal Recovery Act funds algae fuel research. According to the Recovery Act website, the Institute of Gas Technology received a $3.4 million grant to research the conversion of algae into several types of fuel, including diesel fuel and gasoline. Blue Marble Energy is providing some of the algae it harvests from Washington rivers as a sample to use in these experiments.

The main advantage of algae as a biofuel is that it does not compete for resources with any other crops. A water treatment plant normally has to add other chemicals to the water to kill off the algae, and may have to mechanically filter it out. When invasive algae grows in a waterway, this does not reduce the land area that farmers can use to grow corn, soybeans, or other crops that can be used as fuel.

Algae is much more efficient at producing biomass that can be used as fuel than other crops are. According to the National Renewable Energy Laboratory, corn only produces 18 gallons of fuel per acre, and soybeans produce 48 gallons per acre. In the two scenarios for algae production, algae produces 1200 gallons per acre and 10,000 gallons per acre. This is possible because algae grows much faster than most vegetable crops.

Carbon Capture With Algae

Posted by on Friday, 23 July, 2010

Algae already have a vital role in the ecosystem since they can produce oxygen from carbon dioxide in the air through photosynthesis. Algae at a power plant provide the flexibility to capture carbon at the source and reduce the carbon emissions before these emissions reach the atmosphere. As with other plant materials, algae can also be dried or converted into methane to store fuel for later usage.

Researchers at Indiana University are using algae to capture carbon emissions from a power plant on the campus. According to the university, the power plant uses coal, and the more expensive natural gas when its budget allows. Using algae reduces the impact of the fossil fuel usage, although completely capturing all of the carbon from a standard coal plant would require more than a hundred acres of algae ponds. Obviously this is not feasible in many locations, although a power plant at a university in a rural location might be able to successfully set up this type of system.

The University of Illinois is also working on demonstration projects to use algae for carbon capture. According to the University of Illinois, the main advantage of algae is their rapid growth, which requires them to absorb carbon much faster than other plants. Trees and bushes can not match an algal reproduction rate that can double the size of a clump of algae in four hours. The flue gas from the coal plant does first have to be scrubbed of pollutants such as sulfur dioxide which can kill algae, and reduced in temperature to a level that the algae can handle.

Projects in Southern California provide a demonstration of carbon sequestration using algae. A joint project from several research institutions in San Diego, including UCSD, SDSU, and associated research labs, are setting up carbon capture projects in the deserts of Imperial Valley. The algae ponds will require a large amount of space, and the coastal region of San Diego is densely populated and most nearby cities have high land values, but some nearby desert areas are nearly empty because of the extreme heat. Some of the desert regions in this area are part of national parks or military facilities, so the approval process for setting up algae ponds may not always move quickly.