ERC boosts power-plant efficiencies and renewable fuels

As the world seeks renewable sources of energy, much attention is being paid to algae’s potential as a biofuel. Oil companies are investing in algae research, and Congress is considering tax incentives.

Algae requires light, water, nutrients and carbon dioxide to grow. It offers advantages over other biofuels—it is not a feedstock, it can be cultivated in a variety of ways on non-arable land, and it has a high per-acre yield.

A multidisciplinary research group at Lehigh is investigating the feasibility of using CO₂ from power-plant flue gas, or exhaust, and wastewater from municipal water-treatment plants to grow algae that can be converted into biofuel.

Harun Bilirgen, a principal research scientist in Lehigh’s Energy Research Center, gave a report on the project on May 31 during the ERC’s annual Power Generation Technology Meeting. The two-day event drew more than 60 representatives from industry.

Bilirgen is collaborating with Bruce Hargreaves and Donald Morris, professors of earth and environmental sciences, and ERC visiting research scientist Ebru Akkaya. The project is funded by the U.S. Department of Energy and the Ben Franklin Technology Partners of Northeast Pennsylvania.

The researchers’ goal is to produce algae sustainably and at a reasonable cost while optimizing the factors—CO₂, light and nutrient levels; turbulence, methods of removing acids from flue gas—that govern its growth. They will also gauge whether algae can be grown more cheaply in engineered photo-bioreactors than in conventional but land-consuming ponds.

A focus on clean coal and solar

Other presentations covered efforts to make coal-fired power plants operate more cleanly and efficiently:

• ERC director Edward K. Levy discussed the costs and benefits of using heat exchangers to recover heat and water vapor from flue gas. He also gave a presentation titled “Using Waste Heat to Improve Efficiencies of Coal-Fired Units with Carbon Capture.”

• ERC associate director Carlos Romero and research scientist Joshua Charles discussed efforts to reduce the emissions of mercury and condensible particulate matter from power plants.

• Romero also updated a collaboration with the Energy Research Co. that uses laser-induced breakdown spectroscopy (LIBS) and artificial intelligence to enable power-plant operators to make real-time adjustments to limit boiler slagging and fouling.

• ERC research scientist Zheng Yao gave a presentation titled “How China is Reducing Stack Emissions and Improving the Efficiency of Its Coal-Fired Fleet.” Yao and Romero have visited China several times to demonstrate the effectiveness of Boiler OP, a combustion optimization technology developed at the ERC.

• Bilirgen gave a talk on “Optimizing Sorbent Injection Systems for Mercury and Sulfur Oxide Capture.”

• ERC associate director John DuPont Center gave an “Update on Welding Research Activities for Energy Applications.” DuPont, professor of materials science and engineering, is director of Lehigh’s Center for Integrative Materials Joining Science for Energy Applications, a National Science Foundation-funded initiative that involves Lehigh, three other universities and 28 companies.

Sudhakar Neti, professor of mechanical engineering and mechanics, discussed his collaboration with chemical engineers and materials scientists to study the potential of phase-change materials for the high-temperature storage of solar energy.