December 16, 2004 | General

Making A Reality Of Biogas Potential

BioCycle December 2004, Vol. 45, No. 12, p. 45
Continuing breakthroughs in developing projects and new systems for utilizing organic residuals build high hopes for the stalwart innovators.
Jerome Goldstein

DIVERSITY is a prime characteristic of the growing optimism for turning biomass into renewable power sources. Just one year ago, a BioCycle report focused on how the knowledge base, technology breakthroughs and supportive public policies were strengthening the infrastructure for biomass energy. During the past 12 months, investments from generators of organic residuals as well as venture capital firms are leading the way to more commercial projects. The Fourth Annual BioCycle Renewable Energy from Organics Recycling Conference in Des Moines last month confirmed the vitality as well as progress. In the closing plenary session, for example, Zhiqin Zhang of the California Energy Commission reported latest biogas recovery developments from the state’s Public Interest Energy Research (PIER) renewables program. Working with partners like the Western United Resource Dairymen, Milk Producers Council and Sustainable Conservation, the program has 14 projects in operation or final planning stages that involve dairies and the Inland Empire Utilities Agency. Individual project costs range from $75,000 for a covered lagoon system for 175 cows to $4,565,000 for a two-stage plug flow system serving 7,200 cows. Manure from a total of over 33,000 cows will be managed by these anaerobic digestion systems. Total cost of the 14 biogas projects is more than $13 million – further documentation of a growing industry in the biomass conversion sector.
Recent articles in BioCycle reported on some facilities included in the California Energy Commission list. This past spring, a digester at the Straus Family Creamery in Marshall began generating up to 600,000 kWh/year – working with the utility, PG&E. This is the first system to utilize the net metering legislation which allows the on-site power to run meters in reverse as energy is sent back to the grid – saving the dairy $6,000/month energy costs. In the covered lagoon system designed by Doug Williams of Williams Engineering Associates, flushed manure from the dairy along with wastewater from the creamery are pumped to the lagoon for a 40-day retention time. Microbial action converts organic matter into 20,000 to 30,000 cu ft/day of methane-rich biogas. Funds from the Commission helped finance the $280,000 system cost. Dairy owner Albert Straus calculates his capital investment will be paid off in two to three years.
At the Cottonwood Dairy, operated by Joseph Gallo Farms, a new digester system for 5,000 cows will save about $275,000 in annual electrical costs. More than 480,000 gallons/day of manure at one percent solids will be processed in the seven acre covered lagoon system. According to Mike Gallo, CEO for the farm, “the digester lagoon and flush systems provide improved wastewater treatment and storage for the dairy. The cover reduces release of greenhouse gases into the atmosphere.”
In his analysis of “Latest Trends in Anaerobic Digestion in North America”, Richard Mattocks of Environomics based in Salt Point, New York, cites the growing number of biogas systems designers in North America and Europe. “More than 60 firms claim manure and organic waste design capabilities in North America.” (His report will be published in the January, 2005 BioCycle.) His estimates on the anaerobic digestion market in North America have these figures: The market is about $2.5 billion to $3.5 billion; there are as many as 4,000 production facilities appropriate for digestion; average cost of a digestion facility is between $500,000 and $1 million.
Meanwhile states – as well as nations – push forward in passing legislation to accelerate the growth of alternative energy. In Pennsylvania, utilities by 2020 would be required to provide 18 percent of the electricity from such alternative sources as wind, solar, waste coal and biomass. If the bill becomes law, Pennsylvania would become the 18th state to require that a portion of its electricity comes from alternative sources.
On the international scene, last month the U.S. and 13 other countries signed an agreement to work together to capture emissions of methane – which make up 16 percent of the emissions linked to global warming. The U.S. is underwriting $53 million of the costs of the nonbinding methane agreement which calls on participating industrialized countries to use American expertise to develop methods of capturing gas from landfills. The goal is to capture nine million tons of methane by 2015. Other participating countries are Argentina, Australia, Brazil, Colombia, Italy, Japan, Mexico, Nigeria, Russia, Britain and Ukraine.
The goals of the California Energy Commission’s PIER program emphasized by Zhang in her presentation at the Des Moines Renewable Energy Conference are to: Increase and optimize digester gas production from sewage sludge through ultrasound processes; To develop and optimize cost effective biogas cleaning systems; and Evaluate performance and costs during operation so sewage treatment plants have greater certainty when using microturbines.
Assessing the potential of prospective biogas resources in California, Zhang targets these areas: MSW generation – 1 ton/person/year, 35 million population; with an annual growth rate of 1.6 percent, population will reach 70 million by 2048; Sewage sludge and domestic wastewater – 100 gal/person/day at BOD5, 300-400 mg/l, amount of wastewater will double by 2048; Food processing residuals – over 3,000 food processing establishments, plus restaurant wastes; Dairy manure – cow manure (12 percent solids) generation, 16 wet tons/cow/yr, 1.7 million milking cows in 2003 with an annual growth rate of about 1.6 percent, number of milking cows will be doubled by 2048.
Potential biogas power by 2048 from prospective biogas resources (in MWe) are: MSW landfill 465; biogas from sludge – 75; food wastes – 15; livestock manure – 378; Total – 933 MWe. More details on the PIER program are available by visiting:
When it comes to feedstocks for renewable energy, don’t overlook “raw wastewater,” advises civil engineering professor David Bagley of the University of Toronto. The energy stored in Toronto, Canada’s municipal wastewater could contribute power to the utility grid as well as run treatment facilities. In fact, the potential power from one plant’s wastewater would be nine times what’s needed to operate that plant.
As reported in the November 2004 issue of Resource, published by the American Society of Agricultural Engineers, as well as in an academic engineering journal, Bagley’s research shows that the wastewater contains enough organic material to produce 113 mW of electricity or close to 990 million kW hours a year.
Bagley and his research associate, Ioannis Shizas used “bomb calorimetry,” a technique that measures the heat content of materials to determine the amount of energy stored in wastewater’s organic matter. The city plants currently use aerobic treatment. The report in Resource explains that by using anaerobic digestion instead, in which microbes decompose matter without oxygen, the process’s by-product of biogas – with an energy content approximately 75 percent that of natural gas – could become a valuable energy source in the future.
According to Bagley, “We’re moving towards a future where we see our wastewaters and other wastes as resources. If electricity costs go up, this could be a cost-effective and renewable energy source.”
The BioCycle West Coast Conference in San Francisco, March 7-9, 2005 will feature special sessions on renewable energy breakthroughs and policies. Many project designers and developers, as well as site owners, will be reporting their experiences. Cosponsors of the Conference will include the California Integrated Waste Management Board, the California Energy Commission, the USDA, Natural Resources Conservation Service and other West Coast organizations.
In the latest issue of Warmer Bulletin – a world-wide information service on recovering resources from postconsumer wastes – editor Kit Strange writes: “Some people have described the European Union Emissions Trading Scheme (EU-ETS) as the biggest piece of environmental legislation in human history. It will be introduced in January 2005 to help counter global warming.” Once trading starts in earnest, explains Kit Strange, trading screens and financial pages will chart the changing value of carbon emissions: “The numbers will appear on many company balance sheets and internalize a key environmental pressure.”
For biodegradable municipal waste (the organic fraction of MSW), the English government is introducing the Landfill Allowance Trading Scheme. The Waste and Emissions Trading Act provides the legal framework as well for the allocation of tradable landfill allowances to each waste disposal authority in England. “These allowances will convey the diminishing right for a waste disposal authority to landfill over time. Each waste disposal authority will be able to determine how to use its allocation of allowances in the most effective way. It will be able to trade allowances with other authorities, save them for future years or use some of its future allowances in advance. The first year of the trading scheme will begin in England in April 2005.”
At the 21st Annual BioCycle West Coast Conference to be held in San Francisco March 7-9, 2005, Warmer Bulletin editor Kit Strange will discuss latest developments in Europe conveying methods and policies for the recovery of biodegradable wastes.

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