By John Trotti, Kay Martin, and Paul Relis

Mandated Recycling Efforts on Parade
Changing the Equation
What's the Next Step?

"Has the time come to subject organic products, byproducts, and wastes to thermal, chemical, and/or biological degradation?" This was the underlying question posed to a diverse group of industry and government representatives at a meeting held in Santa Barbara, CA, on December 2-3, 1999, jointly hosted by the Wendy P. McCaw Foundation and MSW Management, both of Santa Barbara, CA. The general objective was to explore certain fundamental questions relating to sustainable materials management in the 21st century and the potential role of new conversion technologies in processing portions of the solid waste stream into renewable and environmentally benign fuels, chemicals, and sources of clean energy. Of particular concern was how government policies and functions may need to change to anticipate, catalyze, and respond to these future developments, while ensuring and enhancing environmental protection, resource conversion and recovery, economic development, and other related public policy goals. The proceeding of the colloquy will be published by the Gildea Center in Santa Barbara and subsequently by MSW Management.

Mandated Recycling Efforts on Parade

As were many similar recycling-quota programs, California's AB 939 was driven by three primary concerns: (1) a projected shortfall in landfill capacity, (2) concern over high per-capita waste-generation rates, and (3) a desire to protect natural resources from depletion. Another important factor was opposition to large-scale waste-to-energy projects that, it was feared, would undermine waste prevention and recycling efforts. A decade later, the landfill shortfall has receded, per-capita waste generation is down, recycling has progressed with its resource-saving impacts, and new waste-to-energy project development is nonexistent.

As yesterday’s concerns have largely been answered over the past decade, new and unanticipated issues regarding waste management have emerged. A 1998 EPA study points to landfills as a major source of greenhouse gases and, thus, a contributor to the growing concern over global warming. In response to this threat, President Clinton recently issued an Executive Order (www.bioproducts-bioenergy.gov) calling for the use of biomass, including biomass from municipal sources, as a potential resource for producing green fuels and chemicals. At the same time, EPA and a number of regional and local governmental agencies are encouraging alternatives to the diesel engine and elimination and replacement of methyl tertiary butyl ether (MTBE) as a fuel supplement.

Postrecycled municipal biomass, or that portion of the wastestream that cannot be feasibly recycled, constitutes a large portion of material now destined for the landfill. With the technological advances of the past decade, it may be possible to capture a major portion of this waste and convert it to green fuels, chemicals, and fertilizers through pyrolysis, anaerobic digestion, or gasification. Ethanol- and hydrogen-powered fuel cells could also be the products of such conversion processes. From the standpoint of long-term environmental protection and value added, these conversion technologies, linked with waste prevention and recycling, represent a much more environmentally benign management system than continuing to send more than half of our waste to landfills.

Changing the Equation

Releasing energy through breaking complex carbon-hydrogen bonds is the guiding thermodynamic principal of "bioenergy" generation. The economic potential of this entry into a "carbohydrate economy" that fully recognizes the benefits to be derived from turning waste carbon-hydrogen bonds into commodities offers some attractive opportunities accompanied by some very real concerns and barriers. From the standpoint of technology, however, the conversion of organics into fuels and the transformation of those fuels into power can now be accomplished efficiently and cost-effectively.

As with fuel production for the petroleum industry, adding value through the processing of dispersed resources is critical to economic recycling and resource recovery. Organic conversion system configurations are highly effective and well proven, just as landfill gas–fueled power generation, sewage treatment plant methane cogeneration, and high-solids anaerobic digestion methanogenesis are acceptable examples of distributed energy resources.

An Argonne National Laboratory study concludes that substituting cellulosic ethanol for gasoline could provide a 60-110% reduction in CO₂ emissions, at the same time providing increased marketing potential for a variety of agricultural, forest, and municipal wastes that would substantially reduce landfill disposal and open-field burning of these resources. Cellulosic ethanol is versatile because it can be blended with gasoline or used as a pure fuel. These benefits notwithstanding, there are concerns about cost competitiveness, energy-density characteristics, and opposition by well-established energy interests—all of which must be addressed before these projects will attract the serious attention of venture capitalists. As opposed to corn ethanol—a starch-based fuel produced from the most valuable and nutritious portions of corn—cellulosic ethanol is derived generally from waste products. Its sources include agricultural and forest wastes such as sugar-cane bagasse, rice hulls, and forest thinnings; municipal waste such as waste paper and yardwaste; and industrial waste such as pulp/paper and sludge. Researchers at the National Renewable Energy Laboratory estimate that the United States potentially could convert 2.45 billion mt of cellulosic biomass to 270 billion gal. of ethanol each year—approximately twice the country's annual gasoline consumption.

The Editor’s Comments for the May/June 1999 issue of MSW Management—in noting that because of water-related risks, governing and regulating agencies around the country are beginning to take action to ban the use of MTBE as a fuel oxygenate—suggested that this might provide an opportunity for providing a market for much of the organic fraction in the MSW wastestream. Without MTBE to help meet existing vehicle emissions requirements, ethanol—nearly two times the oxygen content of MTBE—is an obvious replacement. According to Senator Tom Harkin (D-IA), "There is no question that ethanol is the natural choice to replace MTBE in gasoline." Looking only at California, which calls for the removal of MTBE by 2002, financial analysts believe that southern California will need at least 100 million gal. of blended ethanol during winter months to help meet air-quality standards. Additionally, California is expected to use approximately 150 million gal./yr. of ethanol as an octane enhancer.

Industrial ethanol is the most commonly produced of the liquid biofuels, which is not to suggest that the fermentation process is subject to large-scale production. Depending on market demands and the economics of converting organic wastes to commodities, even today's bench-scale projects may find market niches.

While technical questions remain, the major question lies not in the technologies themselves but in how we focus existing scientific knowledge on the interaction of availability of resources, the environment, technology, and market conditions on the development of future recycling systems. And even more to the crux of the matter, how do we align these with such policy areas as waste prevention, productive efficiency, sustainability of natural resources, and the prosperity? Luckily, we're not the only ones asking the questions…nor do we have to start from square one.

The American Chemical Society and Green Chemical Institute held a workshop in conjunction with the US Department of Energy and National Renewable Energy Lab in December 1998 to investigate the production of various chemicals from renewable and environmentally benign bio-based feedstocks. Among the understandings brought forth during discussions was the particular viability of MSW because of its ongoing supply and existing infrastructure.

On July 29, 1999, the Senate Agricultural Committee unanimously supported Senator Richard Lugar’s (R-IN) bill, the National Sustainable Fuels and Chemical Act (S 935), which will advance research on producing fuels, chemicals and electricity from cellulosic biomass. A companion bill sponsored by Representative Thomas Ewing (R-IL) and a similar bill sponsored by Representative Mark Udall (D-CO) were introduced in the House during the first week of September. The concept of converting biomass to cellulosic ethanol is of particular interest to the transportation sector, where ethanol—used mostly as a gasoline oxygenate—is derived primarily from corn. Because cellulosic ethanol utilizes numerous raw materials, not only is feedstock less constrained, but its multiple pathways will provide for greater competition in the ethanol marketplace.

On August 12, 1999, President Clinton signed an Executive Order authorizing a biomass research initiative to further develop strategies for the production of cellulose based fuel, chemicals, and electricity. The Order calls for tripling the nation’s current use of bioenergy and bio-based products by the year 2010 and establishes a permanent council, composed of the Secretaries of Energy and Agriculture, the EPA administrator, and other agency heads, which will develop an integrated biomass research program and promote the use of bio-based products and energy.

What's the Next Step?

The Santa Barbara colloquy identified a number of issues and barrier that participants felt needed addressing, among which are:

• Financing of initial projects…the so-called "Valley of Death."
• Permitting challenges; particularly as MSW rather than traditional production facilities.
• Access to MSW feedstocks in the face of continued industry consolidation.
• Access to markets presently controlled by the large energy companies.
• Reluctance of traditional recycling interests to embrace new technologies for fear of losing hard-won ground.

A number of enabling topics were discussed, many of which involved regulatory action. Most participants felt that while a transfer from petrochemical to bio-based feedstocks for products and energy might come about as development costs of the former continued to rise, short-term prospects hinged on such particular events as a shift from MTBE to ethanol as a fuel oxygenate, or the rise of national security concerns.

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