New algae biofuel concept may cut costs

Most biofuel projects based on the cultivation of algae are failing because of high capital costs, fundamental flaws inherent in production systems, and lack of progress in the science behind algae-culture. For this reason, Biopact and scientists remain sceptical of the current potential of the hyped concept (earlier post, and our interview with Dr Krassen Dimitrov who studied algae systems in depth).

One of the most promising companies, GreenFuel, recently experienced 'successful failure' with its project, resulting in the lay-off of half of its staff. An algae company in South Africa went bust because it couldn't deliver a fraction of what it had promised to investors (previous post). Another one in the US saw its expensive and fragile photobioreactors destroyed in a storm. Some companies have given up on the concept alltogether and simply switched to more robust terrestrial energy cropping instead.

Algae only yield large amounts of biomass when they are grown in a closed environment that allows nutrient flows to be controlled carefully. Such systems based on photobioreactors are extremely expensive and have been dismissed early on by scientists in the 1970s. Instead, open ponds could be used, but here algae cultures rapidly become unstable and yield low amounts of biomass. Large-scale trials conducted in the 1970s and 1980s showed yields are consistently lower than ordinary terrestrial crops. Infrastructure costs, the risk of failed cultures and low yields do not warrant the upfront investments in such ponds.

Still, some are trying to develop low-cost closed environments for algae production, and if the technology works out, then all the better for all of us. The latest attempt comes from Diversified Energy Corporation which has formed a partnership and licensing arrangement for a patent pending system invented by XL Renewables, Inc. The approach, called Simgae (for 'simple algae'), utilizes common agriculture and irrigation components to produce algae at a fraction of the cost of competing systems.

Instead of creating elaborate architectures designed to push yield to its utmost maximum, the proposed system makes cost and simplicity the driving variables. It uses unique thin walled polyethylene tubing, called 'Algae Biotape', similar to conventional drip irrigation tubes (schematic, click to enlarge). The patent pending biotape is laid out in parallel across a field. Under pressure, water containing the necessary nutrients and a small fraction of algae are slowly introduced into the biotape. Carbon dioxide is injected periodically and after roughly 24 hours the flow leaves the Algae Biotape with a markedly greater concentration of algae than was started.

All the supporting hardware components and processes involved in Simgae are direct applications from the agriculture industry. Re-use of these practices avoids the need for expensive and complex hardware and costly installation and maintenance. The Simgae design is expected to provide an annual algae yield of 100 – 200 dry tons per acre (250-500tons/ha):
energy :: sustainability :: ethanol :: biodiesel :: biomass :: bioenergy :: biofuels :: algae ::

Capital costs are expected to be approximately $45,000 – $60,000 (a 2 – 16 times improvement over competing systems) and profitable oil production costs are estimated at only $0.08 – $0.12/pound. These oil costs compare to recent market prices of feedstock oils anywhere from $0.25 – $0.44/pound.

We’ve kept the veil on Simgae until we were absolutely confident in its performance and economics. This is the right technology at the right time to deliver algae biomass for use as a feedstock for biofuel oils, super-antioxidant animal feeds, starches to the ethanol industry, and many other uses. All of this is packaged in a cost effective, easy to install and maintain system that also cleans dirty water and converts carbon dioxide to oxygen through photosynthesis. We are thrilled to be partnered with Diversified Energy to introduce Simgae on a global basis. - Ben Cloud, President and COO of XL Renewables

The companies think that at 1/2 – 1/16th the capital cost, profitable oil production will cost between $0.08 – $0.12/pound, partly due to low operations and maintenance requirements.

Under an exclusive worldwide license, Diversified Energy will provide systems engineering and project management to commercialize the technology.

The team is currently conducting a demonstration of the technology in Casa Grande, Arizona. Continued testing and system optimization is expected to occur through 2008.

Diversified Energy Corporation, headquartered in Gilbert, Arizona is a privately held alternative and renewable energy company focused on maturing innovative technologies, developing commercial energy projects, and providing engineering services support to project developers. Principal areas of expertise include biofuels, gasification, and algae production.

XL Renewables, Inc, Based in Phoenix, Arizona, is developing an integrated biorefinery located in Vicksburg, Arizona, 100 miles west of Phoenix in La Paz County. The $260 million project integrates a modern dairy operation with a biofuels plant to produce ethanol, biodiesel, milk, animal feed and compost fertilizer. The integrated biorefinery utilizes the dairy manure, along with other waste streams to provide 100% of the power, heat and steam needs of the project and significantly lower production costs.

References:
Biopact: Scientist skeptical of algae-to-biofuels potential - interview - July 18, 2007

Biopact: South African algae biofuels company breaks down - June 15, 2007

Biopact: An in-depth look at biofuels from algae - January 19, 2007