February 2013, Vol. 25, No.2

Waterline

Studying watersheds housed under a glass ceiling

University of Arizona ( Tucson ) researchers have moved the watershed indoors to measure what effects rapid, extensive changes in land use and climate have on the ecosystem, according to a university news release. 

The watersheds are housed in the university’s renovated Biosphere 2 Landscape Evolution Observatory (LEO), which is designed to reproduce physical and biological interactions of terrestrial life that occur anywhere between the soil and lower atmosphere, the news release says. 

For this large-scale experiment, an interdisciplinary team of hydrologists, geomorphologists, geochemists, atmospheric scientists, ecologists, and genomicists will study three 30-m (100-ft) by 12-m (40-ft) watersheds. They are designed to mimic the size and complexity of natural landscapes, with slopes supported by steel construction. They are fitted with a network of more than 1800 sensors and samplers that measure the movement of water, energy, nutrients, and carbon, the news release says. 

Through LEO, the researchers will study how surface processes, such as water movement and availability, interact with the atmosphere to better understand biological and hydrological processes under changing climatic conditions and to improve global water resource management, the news release says. 


 

Algae to biofuel in 1 minute?

University of Michigan (Ann Arbor) researchers not only are mimicking nature’s process to form crude oil from marine organisms but also are attempting to optimize and speed up the process. By pressure-cooking algae for as little as 1 minute, researchers can transform 65% of the algae into biocrude oil, according to a university news release.

Phil Savage, an Arthur F. Thurnau professor and university professor of chemical engineering, and Julia Faeth, a doctoral student in Savage’s lab, conducted research to determine the best way to create biofuel by heating algae. During early attempts, the researchers heated algae for 10 to 90 minutes but found they were more successful when using shorter times. They hypothesized that this occurred because reactions that produce biocrude occur faster than previously thought, Savage said in the news release. Quick heating also might prevent or minimize unwanted reactions that reduce the amount of biocrude formed, Faeth added.

The method they developed to extract existing fat from algae and break down proteins and carbohydrates retains about 90% of the energy available in the original algae and takes only about 1 minute. They fill a steel-pipe connector with 1.5 mL of wet algae from the Nannochloropsis genus of green marine microalgae, cap the pipe, and bury it for 1 minute in sand heated to 593°C (1100°F). The small volume of algae ensures that the sample is heated through. The temperature of the algae reaches about 288°C (550°F), the news release says.

The researchers now are developing better methods to prerefine the fuel to remove excess oxygen and nitrogen atoms so it can be fed into existing refinery systems. They also noted that the system requires more development to see if the process can be made cost-effective, the news release says.

The research, titled “The Effects of Heating Rate and Reaction Time on Hydrothermal Liquefaction of Microalgae,” was funded by the U.S. National Science Foundation Emerging Frontiers in Research and Innovation program. The university is pursuing a patent for the technology and seeking partners to help commercialize it, the news release says.