Linda Benedict, Oard, Svetlana
Hydrogen is an appealing energy carrier because of its potential for using the most plentiful resources – water and sunlight – to power one of the most environmentally clean reactions, 2H2O = 2H2 + O2, in which two water molecules yield two hydrogen molecules and one oxygen molecule. The United States, the European Union and Japan have already embarked on establishing hydrogen fuel stations, and in parallel, car manufacturers have invested extensively in the development of hydrogen fuel cells to power cars.
Scientists recently discovered that green microalgae, or phytoplankton, can produce hydrogen. The development of microalgae-derived hydrogen could deliver the means for a solar-powered, carbon dioxide-sequestering (and therefore economical and intrinsically environmentally safe) biofuel. The warm and humid climate makes Louisiana one of the most suitable states for industrial-scale production of microalgae through inexpensive, pond-based systems. Algal ponds can be established on nonarable land otherwise unsuited for growing crops. This means more business opportunities for Louisiana. Moreover, there will be no competition between biofuel crops and food crops.
Many people believe that algae-based technologies will lead to new fast-growing biofuels and have a huge potential to boost Louisiana’s economic development. The research to create microalgae for hydrogen production will require a united effort of scientists with expertise in advanced computer modeling, quantum chemistry, enzymology, genetics and biological engineering. The natural enzyme that produces hydrogen in microalgae is sensitive to the presence of oxygen. Scientists have to re-engineer the enzyme to make it oxygen-tolerant. This will radically improve the current capability of microalgae to produce hydrogen. Fortunately, the AgCenter has scientists willing to rise to the challenge. They are in the process of establishing collaboration with scientists from the National Renewable Energy Laboratory, a unit of the U.S. Department of Energy.
An economical process has to include three components: scalable and economical algae cultivation, improved microalgae capable of producing hydrogen in the presence of oxygen, and commercial use of hydrogen as a transportation fuel. LSU AgCenter scientists have designed and built a reactor for mass producing algae and have developed an aquaculture system utilizing a fuel cell to maintain oxygen levels.
To engineer microalgae with improved capability to produce hydrogen, the first step is to use advanced computational methods to investigate the effects of oxygen on the structure and dynamics of the hydrogen-producing enzyme hydrogenase. Knowledge gained from this process will help guide the design of improved, oxygen-resistant enzymes, which will be tested experimentally in a model organism. The next step is to develop a controlled production system that will produce the active hydrogenase under desirable conditions in microalgae. The production system will be used to introduce improved enzymes into microalgae to increase hydrogen production.
A successful research and development project will open doors for many new jobs in Louisiana and will have a broad national and international effect because of the worldwide importance of economical hydrogen production. Hydrogen can be converted into electricity, and manufacturers are developing automobiles that use hydrogen as a fuel. In addition, chemical companies use tons of hydrogen for hydrogenation reactions. Hundreds of millions of tons of ammonia fertilizer are produced annually using hydrogen and nitrogen. Most hydrogen currently comes from reforming natural gas and refining petroleum. Consequently, these large-scale hydrogen consumers are among the existing industries that can use this technology. Thus, invention of an economical process for producing hydrogen biofuels with microalgae will have a major, positive effect on several industries in Louisiana and beyond.
Svetlana Oard, Associate Professor, LSU AgCenter Biotechnology Laboratory, Baton Rouge, La.
(This article was published in the fall 2009 issue of Louisiana Agriculture.)