Algae Bioreactor to Generate Biofuels from Smokestack CO₂

An algae bioreaction system that recycles CO₂ from power and manufacturing plant flue gases and converts it to an onsite, continuous supply of biofuel, such as biodiesel, ethanol or methane has been licensed to the Victor Smorgon Group (VSG) by GreenFuel Technologies of Cambridge, Massachusetts. VSG is to have exclusive license to distribute, install and operate GreenFuel's Emissions-to-Biofuels™ proprietary technology for growing, harvesting, and processing biomass and products derived from algae throughout for Australia and New Zealand.

The technology has been proven in two pilot programs. The second and larger unit was commissioned at a 1,060 MW combined cycle facility in 2005 in the southwest United States. The bioreactor productivities suggest annual yields of 5,000-10,000 gallons of biodiesel and a comparable amount of bioethanol per acre.

With low construction, energy and operational costs, the process mitigates CO₂ emissions profitably and is able to produce algae growth rates consistently higher than those ever achieved before. The system does not impact the operations of the power plant, and is designed to be retrofitted to flue stacks with minimal impact on ongoing operations.

How It Works

CO₂-rich gas streams are introduced to the bioreactor, in which algae are suspended in a media with nutrients added to optimize the growth rate. A portion of the media is withdrawn continuously from the bioreactor and sent to dewatering to harvest the algae. The dewatering operation uses two stages of conventional processing. Primary dewatering increases the algae concentration by a factor of 10-30. Secondary dewatering further increases the algal solids concentration to yield a cake suitable for downstream processing. Water removed from the dewatering steps is returned to the bioreactor, with a small purge stream to prevent precipitation of salts. Make-up water is added to maintain the media volume. A blower pulls the flue gas through the bioreactor. Using an induced draft fan provides several operating advantages, including ensuring minimal disruption to power plant operations, simplifying retrofits to existing facilities.

The “downstream” unit operations for algal oil extraction and conversion of the dewatered algae into final fuel products, in contrast to the ”upstream” unit operations, are conventional technologies currently practiced on a large scale, e.g. biodiesel is currently produced from vegetable oils via transesterification (several algae species have lipids, starch, and protein compositions similar to soy and canola beans). Consequently the same facilities can be adapted to produce biodiesel from algae and conventional agricultural feeds. Some downstream processing options are listed below:

According to Peter Edwards, Managing Director of VSG, installations are quite site specific, with effectiveness depending upon several factors such as water quality, light, flue gas composition and land availability. Thus implementation will usually proceed in a three stage process:
Site feasibility study
Mini plant
Full sized plant

Background to the companies involved:

Founded in 1995, VSG is involved in manufacturing of biodiesel and plastics, aquaculture, and has successfully implemented recycling processes in the paper, glass, steel, and plastics industries - as well as retailing youth branded clothing.

"The GreenFuel Emissions-to-Biofuels process has tremendous potential as a new source of clean, renewable energy and a solution to a growing greenhouse gas emissions problem," said Peter Edwards, Managing Director of VSG.

According to Cary Bullock, CEO of GreenFuel Technologies Corporation "VSG has put together a talented and experienced management team to drive the GreenFuel Emission-to-Biofuels™ project development and marketing efforts in an important region of the world. The combined engineering talent and industry experience of our two organizations is an excellent formula for accelerated results and a successful partnership."

With more than a dozen pending patents, GreenFuel Technologies was founded in 2001 by Isaac Berzin, who now serves as Chief Technology Officer.

For more information:
www.greenfuelonline.com
www.bioenergyaustralia.org

Disclaimer: The Warren Centre publishes articles relating to new technology and innovation that are often based on information supplied by third parties. While an editorial process is applied, we make no exhaustive investigation into the accuracy of the information, thus no liability will be accepted for its accuracy. Please note that in providing this information, The Warren Centre is not supporting or promoting any technology or company, merely seeking to inform. Interested readers should take their own steps to verify the information prior to relying on it in any way.

The CO₂ to Biofuels Process

Contents

Water-Who's in Charge

Bridge Structural Repairs Using Performance Carbon Fibre
Innovation – do Australia's big companies get it?
Algae Bioreactor to Generate Biofuels from Smokestack CO₂
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(c) The Warren Centre for Advanced Engineering, August 2006