J T's List: Algae Bio-fuel

• Genomicist Craig Venter and his company Synthetic Genomics Incorporated (SGI) have entered into a $600m strategic alliance with Exxon Mobil to develop a next-generation biofuel from photosynthetic algae. Algae absorb carbon dioxide and sunlight in aqueous environments, producing an oil of similar molecular structure to contemporary petroleum products. Algal fuel can be refined, transported and distributed using existing refineries, pipelines and service stations and can run the engines of today’s automobiles and airplanes.
• Several advantages of algae over traditional biofuels are that algae produce significantly higher amounts of oil and biomass, aid environmental remediation through the absorption of atmospheric carbon dioxide and do not force the polemical tradeoff of food for fuel by occupying agricultural lands

• Due to the high costs associated with producing crude algae oil for the aviation, ground transportation, and other fuel end-markets, most industry ventures have pivoted away from a fuels-first approach to focus on the development of revenue streams from high-value, low-volume co-product markets

• Strong demand from aviation and military consumers, technological breakthroughs in the production, cultivation, and extraction of algae oil, and the development of large-scale projects will be critical to widespread growth in the algae-based biofuels market.

  "Scale-up of algae-based biofuels will depend on the realization of value in non-fuel end-markets. As key capital and operating cost hurdles are overcome, algae-based biofuel production should expand rapidly."
• the scale-up potential of algae is substantial compared to other non-food based feedstocks. Although regulatory and policy uncertainty as well as competition from co-product markets will inhibit algae-based biofuels production initially, the cleantech market intelligence firm projects that the value of renewable fuels derived from algae will reach $1.3 billion by 2020.
• Algae can be grown on non-arable land, co-located with stationary CO2 emissions sources, and utilize a wide variety of water resources including wastewater and seawater. A number of algae ventures are making important headway with different strategies for maximizing yields while capitalizing on innovative pathways to mitigate the externalities associated with fuel and chemical production.
• North America and Asia Pacific are projected to account for 82 percent of algae-based biofuels production in 2020, representing at least 50 million gallons of algae-based biofuels per year.

3 more annotations...

• 
  

  Commercialization of algae-based biofuels can create jobs, increase energy security, and reduce greenhouse gas emissions on par with other advanced biofuels, but algae producers are at a disadvantage in attracting investment because these biofuels are not currently recognized in the tax code as advanced biofuels
• Algae-based biofuel technology is advancing rapidly and is ready for commercialization. Production of algae-based biofuels can generate thousands of domestic green jobs in facility construction and operation and have the potential to greatly enhance our country's energy and environmental security," Brent Erickson, executive vice president for BIO's Industrial and Environmental Section
• Unfortunately, though, algae-based biofuel developers do not qualify for existing tax incentives for advanced biofuel development. It is extremely challenging for algae-based biofuel start-up companies to attract the capital required for facility construction, due to this disparate treatment under the tax code. Fixing this discrepancy and granting algae-based biofuels tax treatment similar to other advanced biofuels can open the way to greater job creation and economic growth," Erickson concluded.

1 more annotation...

• The use of fossil fuels as energy is now widely accepted as unsustainable due to depleting resources and also due to the accumulation of greenhouse gases in the environment
• Biofuel is a renewable energy source produced from biomass, which can be used as a substitute for petroleum fuels. The benefits of biofuels over traditional fuels include greater energy security, reduced environmental impact, foreign exchange savings, and ü socioeconomic issues
• Once again these smallest organisms are poised to save us from the threat of global warming.
• Algae are simple organisms that are mainly aquatic and microscopic. Microalgae are unicellular photosynthetic micro-organisms, living in saline or freshwater environments that convert sunlight, water and carbon dioxide to algal biomass

• Microalgae cultivation using sunlight energy can be carried out in open or covered ponds or closed photobioreactors, based on tubular, flat plate or other designs. Closed systems are much more expensive than ponds, and present significant operating challenges, and due to gas exchange limitations, among others, cannot be scaled-up much beyond about a hundred square meters for an individual growth unit.

  Nutrients can be provided through runoff water from nearby land areas or by channelling the water from sewage/water treatment plants. Microalgae cultivation using sunlight energy can be carried out in open or covered ponds or closed photobioreactors. Algal cultures consist of a single or several specific strains optimized for producing the desired product. Water, necessary nutrients and CO₂ are provided in a controlled way, while oxygen has to be removed [10]. Algae receive sunlight either directly through the transparent container walls or via light fibers or tubes that channel it from sunlight collectors. A great amount of developmental work to optimize different photobioreactor systems for algae cultivation has been carried out and is reviewed
• Since microalgae have high water content, not all biomass energy conversion processes can be applied. By using thermochemical processes, oil and gas can be produced, and by using biochemical processes, ethanol, biodiesel and bio-hydrogen can be produced
• Open pond systems are shallow ponds in which algae are cultivated. Nutrients can be provided through runoff water from nearby land areas or by channeling the water from sewage/water treatment plant
• The only practicable methods of large-scale production of microalgae are raceway ponds [18] and [19] and tubular photobioreactors
• Their productivity is measured in terms of biomass produced per day per unit of available surface area
• Careful control of pH and other physical conditions for introducing CO₂ into the ponds allowed greater than 90% utilization of injected CO₂.
• Raceway ponds for mass culture of microalgae have been used since the 1950s. Extensive experience exists on operation and engineering of raceways. The largest raceway-based biomass production facility occupies an area of 440,000 m² [23]. Productivity is affected by contamination with unwanted algae and micro-organisms that feed on algae.
• The open pond cultures are economically more favorable, but raise the issues of land use cost, water availability, and appropriate climatic conditions. Photobioreactors offer a closed culture environment, which is protected from direct fallout, relatively safe from invading micro-organisms. This technology is relatively expensive compared to the open ponds because of the infrastructure costs. An ideal biomass production system should use the freely available sunlight.
• Photobioreactors have higher efficiency and biomass concentration (2–5 g/L), shorter harvest time (2–4 weeks), and higher surface-to-volume ratio (25–125/m) than open ponds
• A turbulent flow is maintained in the reactor to ensure distribution of nutrients, improve gas exchange, minimize cell sedimentation, and circulate biomass for equal illumination between the light and dark zones.
• Flat-plated photobioreactors are usually made of transparent material. The large illumination surface area allows high photosynthetic efficiency, low accumulation of dissolved oxygen concentration, and immobilization of algae [31]. The reactors are inexpensive and easy to construct and maintain. However, the large surface area presents scale-up problems, including difficulties in controlling culture temperature and carbon dioxide diffusion rate, and the tendency for algae adhering to the walls.
• The system worked, and 15–30% of algae were harvested each day. The setup was able to remove 82% carbon dioxide on a sunny day and 50% carbon dioxide on a cloudy day. Nitrogen oxide was also lowered by 86%
• Harvesting the algae from tanks and separating the oil from the algae are difficult and energy intensive processes [34]. The culture of algae in ponds or tanks and, the harvesting of the algae is major problem. Because algae are mostly water, harvesting the algae from the cultural tanks and separating the oil from the algae, is a difficult and energy intensive process [35].
• However, interrupting the carbon dioxide supply to an algal system can cause algae to flocculate on its own, which is called “auto-flocculation”. In froth flotation, the water and algae are aerated into froth and algae in then removed from the water.
• Capital/operating costsOpen ponds  PBRs   Biomass concentrationOpen ponds < PBRs   Oxygen inhibitionOpen ponds > PBRs   Contamination riskOpen ponds < PBRs   Water lossesOpen ponds  PBRs   Carbon dioxide lossesOpen ponds  PBRs   Process controlOpen ponds  PBRs   Space requiredOpen ponds  PBRs
• Such quantities of nitrogen and phosphorus could damage the environment. Additionally, it could limit the economic viability of using microalgae. Nitrogen and phosphorus found in algal waste, after the oils have been extracted, must therefore be recycled.
• processing requires less energy than the algae provides.

19 more annotations...