July 25, 2007 | General

BioCycle World

BioCycle July 2007, Vol. 48, No. 7, p. 6

Biogenic Content Of MSW As Renewable Energy
The U.S. Energy Information Administration (EIA) released a report in May 2007 that classifies only the biogenic portion of municipal solid waste (MSW) as a source of renewable energy. Historically, because MSW has widely been viewed as principally composed of biomass, EIA had classified all consumption at MSW combustion plants as a renewable portion of “Waste Energy.” However, said the May 2007 EIA report, “MSW clearly contains nonrenewable components, raising a concern that EIA has been overstating the renewable content of MSW.” EIA investigated whether sufficient information exists to reasonably divide MSW into its biogenic and nonbiogenic portions. The agency determined enough data existed and will now include MSW in renewable energy only to the extent that the energy content of the MSW source stream is biogenic. EIA recognizes that the definitions of renewable energy used for state and federal energy policy purposes – including state Renewable Energy Portfolio Standards – differ widely as to whether and to what extent MSW is included. “As a source of policy-neutral energy data, it is important for EIA to apply a consistent approach to defining renewable energy in its standard data reports,” explains EIA in its findings, “Methodology for Allocating MSW to Biogenic and Non-Biogenic Energy.”
Biogenic MSW materials include newsprint, paper, containers and packaging, textiles, yard trimmings, food waste, wood and leather. Nonbiogenic MSW includes plastics and rubber. EIA’s data for 2005 found that the total heat content of MSW (million Btu/ton) was 11.73. Of that, 56 percent is biogenic and 44 percent is nonbiogenic. By comparison, in 1989, biogenic materials contributed two-thirds of the heat content of the waste stream. The report can be downloaded from the EIA website (http://
Compost Toilets In Malawi
Water For People was awarded a Development Marketplace grant of $200,000 for an innovative sanitation project in Malawi designed to reduce the incidence of diarrhea through hygiene education, the use of children’s latrines, and the production of compost for sale. The grant program is financed by The World Bank and the Bill and Melinda Gates Foundation. The overall goal of the Water For People proposal is to reduce diarrhea by 40 percent in two rural Malawian traditional authorities, including 31 schools and more than 100 villages, by improving sanitation practices and facilities. The multifaceted approach targets toddlers and young children by promoting the use of ecological latrines while eliminating open defecation common in the region. The program includes the distribution of child-size “arbor-loos” that allow children to defecate safely and then, when the pit latrine is full, they can plant a tree and move the toilet to another location. The program also includes a component targeted at adults, where latrines are constructed that can transform fecal waste from a health threat to valuable compost that is then sold. The program uses children as agents of change at school and in the household, a model that has proven effective for promoting long-term changes in health and hygiene practices. “With this award, the program will become a reality,” says Ned Breslin of Water For People. “Our selection suggests that our work really stood out, as it offered a unique way to tackle diarrhea which is the second largest killer of children worldwide. It also suggests that the centrality of water and sanitation to improved health is understood.”
Water For People is a Denver-based private, nonprofit international development organization that supports safe drinking water and sanitation projects in developing countries. It partners with communities and other nongovernmental organizations to help people improve their quality of life by supporting sustainable drinking water, sanitation and health and hygiene projects. For more information, visit
Australian Researchers Test Digestion And Composting Of Organics
“Food waste, green organics and digested biosolids can be used as an integrated waste management system that uses anaerobic digestion followed by aerobic composting,” explain R. Dearman and R.H. Bentham of Flinders University in South Australia. “Together, these processes rate very highly in life-cycle assessment, but there are technical issues that need to be investigated.”
In a research paper submitted to Compost Science & Utilization, they report that sequential batch aerobic systems generated methane rates but that composting the sludge was difficult due to the physical form of the materials and low available carbon content. Grass clippings provided a high proportion of readily available carbon.
“The anaerobic material complements this readily degradable component of grass clippings with a combination of a more complex organic structure and high nitrogen content,” explain Dearman and Bentham. “This suggests that the anaerobic material would be an excellent supplement for composting green organics and similar materials, which typically have a low nitrogen content. Odor problems were minimized by combining these green organics, and there was no detectable ammonia odor or unpleasant smell from the compost after three weeks, indicating that maturation time was complete. The physical composition of the composted end product was a rich mulch type compost. This made it a Class B material that can be used for site beautification and rehabilitation, based on South Australian EPA guidelines.”
The Sixth Waste Data Digest published by Scottish Environment Protection Agency details data collected on controlled waste in Scotland. This survey was designed to allow the progress in reaching targets for recycling and composting of municipal waste to be monitored, reports a 2007 issue of Warmer Bulletin. Recyclables were collected through curbside and drop-off programs which consisted of 159 local recycling centers and 2,016 sites.
In 2005/06, 181,450 tons of residuals collected by Scottish local authorities were composted. In addition, roughly 8,000 tons were disposed of before composting, and 7,000 tons were used as daily cover for landfill sites. Majority of waste sent for composting was green waste (157,499 tons) with the remainder being mixed organics (l6,664 tons) and mixed MSW (14.321 tons). Most residuals sent for composting originated from curbside collection of green waste, local authority recycling centers, and local parks.
Canadian Composting Council Lists Compost Sites, Amounts And MethodsUsed
A survey by the Composting Council of Canada shows that four million metric tons of organics were composted in 2005, generating more than 2.4 million tons of finished product. According to Susan Antler, executive director, composting recovers approximately 12 percent of the waste stream. There are 227 composting sites now, with 123 that are municipally operated, 85 private businesses. and 19 that have a public/private partnership. About 1,700 persons are employed at the sites.
Compostable feedstocks include leaf and yard trimmings (78 percent of facilities receiving), organic residuals from private companies (72 percent), residential food residuals (29 percent). Most common method is windrow composting used at 165 sites. Sums up Antler: “Composting provides a sustainable solution to landfilling, reduces greenhouse gas emissions while producing compost. It is a proven means to help communities sustainably manage their organic residuals.”
The regional breakdown showed the following tonnages composted in 2005: Western Canada – 868,000 metric tons; Ontario – 682,000 metric tons; Quebec – 1,006,000 metric tons; and Atlantic Canada – 1,394,000 metric tons.
Renewable Energy Registry For Electricity Generation
The California Energy Commission (CEC) announced the launch of the Western Renewable Energy Generation Information System (WREGIS), a renewable energy registry and tracking system for electricity generation. The system is the largest of its kind in the world in terms of coverage and includes the western United States, western Canada, and a small portion of Mexico. It will be used to meet renewable portfolio standard requirements and other renewable energy policies for states and provinces within the Western Interconnection transmission area, which covers Arizona, California, Colorado, Idaho, Montana, Nebraska, Nevada, New Mexico, Oregon, South Dakota, Texas, Utah, Washington and Wyoming; the Canadian provinces of British Columbia and Alberta; and the northern portion of Baja California in Mexico.
The voluntary WREGIS system was developed in response to policies set by the California legislature and the Western Governors’ Association (WGA). WREGIS will track the renewable generation to help ensure the credibility of the “green” value of renewable electricity, states a CEC press release. “Using independent, verifiable and reliable data, the system will make it easier to implement renewable policies and achieve renewable energy goals.” Data in WREGIS includes megawatt-hours produced, fuel source, facility location, and all state, provincial and voluntary renewable energy program qualifications. One WREGIS certificate is issued for each megawatt-hour of renewable energy produced and deposited on the grid. To prevent double counting, each WREGIS certificate has its own unique serial number.
WREGIS will help WGA track its progress on a goal set in 2004 to develop an additional 30,000 megawatts of “clean” energy by 2015, drawing on both traditional and renewable resources. According to a progress report released in June, the Western states are well on their way to that goal, with more than 4,000 megawatts of new renewable generation added in 2005 and 2006 and 3,432 megawatts of new renewable generation projected for 2007. Wind power provided about 93 percent of that new renewable capacity, but the numbers also include 164 megawatts of new geothermal capacity, 92 megawatts of biomass power, 216 megawatts of grid-connected solar photovoltaic power, and 65 megawatts of central station solar power.
Using The European Union To Set Priorities For Waste Utilization
Writing in The Pennsylvania Recycler, John Frederick – executive director of the Professional Recyclers of Pennsylvania who visited Austria and Germany last year to explore “transfer possibilities” – noted how those countries seek to reduce landfill disposal by 65 percent in 2016. The strategy is to convert high levels of residuals into compost and energy. “While food production has become more of an ‘industry’ in America,” writes Frederick, “farming and composting have a more local flavor in Europe.”
The group visited both ends on the technological continuum. In addition to digesters, they saw closed vessel systems in Ilbenstad and Wurzburg. Program coordinator Rick Stehouwer, Professor of Crop and Soil Science at Penn State University, noted how proximity to urban areas made closed vessel technologies more attractive, especially in Germany.
Participants felt that things happening in Europe were transferable to Pennsylvania, but differences in economics make the transition more difficult. “We have to create the economics to make it more attractive,” concludes Stehouwer. “Perhaps we have to restrict what we allow to be disposed of.” They also noted the successful partnerships that have been built. “We need to look at getting organic waste out of the ‘landfill stream.’ I only see positives for both in doing so.”

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