WASTEEXPO 2006: Seeking Alternatives

Waste Conversion Technologies (WCTs) for municipal solid waste processing are growing popular in Europe and piquing interest in the United States as alternatives to landfill and incineration, according to a presentation given at WasteExpo 2006.

Theodore S. Pytlar Jr., vice president of Dvirka and Bartilucci Consulting Engineers in Woodbury, N.Y., said that with landfill area becoming scarcer, MSW must be shipped further and further. With rising fuel costs, those conditions are contributing to economic incentives for the United States to look into alternatives to landfill and incineration.

WCTs have been receiving more attention in Europe where European Union legislation, efforts to comply with the Kyoto Protocol and reluctance to propose combustion-based waste-to-energy facilities have been driving efforts to find new technologies.

Pytlar said that while the United States lacks the regulatory impetus faced by many European countries, some states and communities are investigating WCTs. He said California legislation has required the California Integrated Waste Management Board (CIWMB) to “research and evaluate new and emerging non-combustion thermal, chemical and biological technologies,” for instance.

WCTs produce intermediate products from MSW that can be used in energy generation or chemical manufacturing, according to Pytlar. One method is anaerobic digestion, a process similar to composting, which treats biodegradable material with bacterial action in the absence of oxygen. The process generates a biogas that can be used for electricity generation and heat. Pytlar said the technology is commonly applicable in sludge management and wastewater treatment.

Another technology under consideration is ethanol production, which produces a liquid fuel. However, Pytlar said no facilities converting MSW to ethanol are operating in the United States or the world.

Thermochemical technologies are also being considered, including gasification, a process involving the conversion of solid or liquid feedstock into gas by means of partial oxidation and heat. Pytlar said there are a number of commercially active gasification facilities using MSW operating in Japan and Germany.

Pytlar pointed out that WCTs do not eliminate stack emissions and that the types of pollutants emitted by gasification systems are similar to those of waste-to-energy systems. However, according to information presented by Pytlar, dioxin and furan emissions have been reported by WCT vendors as lower than those of WTE systems, although WTE emissions are well below U.S. EPA standards.

Carmen Cognetta of the New York City Council also addressed attendees on the topic, saying that New York has begun considering some of the WCTs for its disposal needs.

“We’re under tremendous pressure to be sustainable,” Cognetta said, adding that the cost of shipping New York’s MSW elsewhere for disposal has pushed the city to investigate alternatives.

Anaerobic digestion and gasification technologies are two of the methods under consideration in New York, Cognetta said.