Tag Archives: Hawaii Natural Energy Institute

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.

Breaking down plastics

Image of microbial cells and biopolymer granules (bar 500 nm).
Image of microbial cells and biopolymer granules (bar 500 nm).
In a world where plastic bags and plastic bottles are consumed in the millions annually, the fight to reduce such waste seems a daunting battle. Consumers are doing their part by becoming more socially aware about these environmental issues and making a conscientious effort to buy products and technology that are sustainable and eco-friendly. In response, Jian Yu, an associate researcher with UH Mānoa’s Hawaii Natural Energy Institute, and his team, are creating new technology to meet the increasing demands in the marketplace.

Yu’s research has led to the creation of thermoplastic materials from renewable feedstocks, such as agricultural wastes and food processing byproducts. The bio-based plastics, called PHA (polyhydroxyalkonoate) bioplastics, are completely biodegradable and biocompatible, whereas their petroleum-based counterparts are not. Petroleum-based plastics are not biodegradable and eventually find their way to the open seas, killing hundreds of thousands of birds, fish and other marine animals every year. “Compared to the conventional plastics, bioplastics consume less fossil energy and release much less greenhouse gases as indicated by numerous life-cycle analysis,” said Yu.

Biodegradable plastics were introduced about 20 years ago when a biochemical company had a successful pilot production of the biopolyesters from glucose and propionic acid. The bioplastics were used to make various goods such as shampoo bottles, credit cards, syringes and containers.  While its ecofriendly properties were groundbreaking at the time, the high costs associated with producing the product prevented it from being widely marketed.

A chemical/biochemical engineer by training, Yu was excited by the research that could lead to new technologies to bring down the high cost of production.  “I first investigated if cheap but complicated raw materials such as food scraps could be used for biopolymer production by microbial organisms,” said Yu.

His research was successful and gained recognition from his peers, including a published paper in Environmental Science and Technology in 2002. “Now, the technology has been used for other cheap feedstocks, such as sugar molasses, a residue from sugar manufacturers, and crude glycerol waste discharged from biodiesel production,” shared Yu. “We are able to achieve a very high special productivity rate for commercial production.”

Yu’s PHA bioplastics technology consists of three parts, including (1) pretreatment of feedstocks into suitable substrates for a special type of microbial organism, (2) high cell density fermentation for biosynthesis of biopolyesters, and (3) solvent-free recovery and purification of biopolyesters to make the final product of bioplastics.

At the end of fermentation process, their cells can accumulate 60-70 percent biopolyester of their mass.  In order to purify the biopolymer for bioplastics, the rest of the 30-40 percent of residual cell mass must be removed in a cost effective way. One conventional technology relies on organic solvent extraction, which is not only expensive, but also environmentally unfriendly. “We developed a new technology in which no organic solvent is needed, and at the same time, the cell debris generated from recovery process can be reused in biopolymer production,” added Yu.

The technology shows real potential. He already has a commercialization plan in place and has filed two patents on the technology, which is being used in a pilot plant in Europe. “The pilot plant has been built up according to our specifications and has been running successfully, providing data for scaling up to a commercial production,” said Yu. The company that operates the plant has invested $2 million to establish a central testing center in Honolulu, Hawaii, that will provide characterization and analysis service to its global manufacturing and markets.

In terms of waste reduction, Hawaii will see the benefits of Yu’s research. With large quantities of biomass generated by the state every year, the “green garbage” can be used as renewable feedstocks to make the bioplastics using their biorefining technologies.  “We have no oil resource for a petrochemical industry, but it is highly possible to have a manufacturing industry based on its plentiful renewable resources,” added Yu.

Although the price to make bioplastics is still higher than those of oil-based plastics, Yu believes his research will lead to technologies that can reduce the high production cost and bring the bioplastics to the consumers at a competitive price, in hopes of averting a mass environmental disaster. “The product exhibits good properties and can compete with similar products if the production cost can be reduced to a level widely accepted in the markets,” said Yu. Until then, consumers can count on more green products to hit the marketplace for years to come.

For more information, visit the Hawaii Natural Energy Institute website at http://hnei.hawaii.edu.

For more about the exciting research now being conducted at the University of Hawaiʻi at Mānoa read Inspiration to Innovation – the Chancellorʻs Report 2011-2012 (pdf).

Top photo: Yu sits in front of a bench top bioreactor in which microbial cells are cultivated for biopolymer production.