Tag Archives: high-rate anaerobic digestion

Rendering of Anaerobic Digester_Cooney

Turning waste into resource

Michael Cooney
Michael Cooney
The sustainability movement is pushing forward in new directions, with innovative concepts being developed by researchers around the globe.  Among them is Michael Cooney, an associate researcher with the Hawai‘i Natural Energy Institute (HNEI) at the University of Hawai‘i at Mānoa, who is leading a group of researchers to develop a simple and a relatively cost-effective way to convert solid and liquid waste into energy and useful products, such as soil amendments. Their efforts—literally a million-dollar idea—will help enrich our soils and conserve our natural resources over the next 10 years.

A recent campus-wide $1 million sustainability competition administered by the Office of Vice Chancellor for Research and Graduate Education, won by Cooney and faculty from various departments, will advance a two-fold venture that he hopes will create pathways for local companies through incorporation of UH developed technologies that produce energy and soil enhancers.

The winning two-year project, titled “Water, Energy and Soil Sustainability,” will help support research to evaluate the treatment of liquid waste streams through application of high-rate anaerobic digestion and solid waste through the application of flash carbonization.  The two processes will also be integrated to produce treated biochar, or agricultural waste turned into a soil enhancer that holds promise to aid soils for growth of energy crops and food crops.

In one component of this project, field soils on Maui are currently supporting high yields from Jatropha curcas, an energy crop that is receiving serious consideration among researchers and farmers in Hawai‘i.  The fast-growing, drought-resistant, tropical oil-bearing plant is rich in fatty oils that can be converted to biodiesel.

These results are currently being used in greenhouse trials on corn to evaluate how best to apply biochar to less productive soils as a means to duplicate the field trials. Though more assessments are necessary, positive results have been found for soils amended with treated biochar.  “Preliminary characterizations of the soil supporting this productivity are suggesting that the attractive yields are due to water and nutrient retention capacity of the soil,” said Cooney. “It is our hope we can show that treated biochar added to poor soils can actually support growth leasing to yields that compete with those currently achieved on Maui with the Jatropha crop.”

Other projects in the works include making biochar out of dried anaerobic sludge and evaluating its value as an energy source or soil amendment/fertilizer. “If that proves successful, there is the potential to carbonize a solid waste—that is currently sent to landfill—and turn it into a product that produces revenue,” said Cooney.

Cooney’s project team includes researchers and students from UH Mānoa’s Department of Tropical Plant and Soil Science Program, the Shidler College of Business, Hawai‘i Natural Energy Institute and the Department of Oceanography.  He is also working with Shidler’s Pacific Asian Center for Entrepreneurship and E-Business, which is funding business, law and science graduate students to develop business plans evaluating the Jatropha crop growth as a commercial business in Hawai‘i.

Green companies in Hawaii have also taken note of Cooney’s research and collaborated with him on various projects. “One key output of about our program is an effort to develop research agreements with local companies that permit the evaluation of UH technology around commercial processes that have in place,” said Cooney, “with the hope of adding value to their existing production processes through the energy efficient treatment of liquid and solid waste streams, and in a manner that potentially helps them develop new product streams.”

For more information, visit the Hawai‘i Natural Energy Institute website at http://www.hnei.hawaii.edu.

Top photo: Artist rendering of high-rate anaerobic digesters being put in place at the Hawaii Kai Wastewater Treatment facility.