New waste management concepts in the reduction of greenhouse gas emissions

Globally, solid waste disposal causes about 3-4% of anthropogenic greenhouse gas emissions. The most significant emission source is methane production at landfills. The opportunities for export of new waste treatment technologies, solutions and know-how have improved due to the emission reduction requirements and the fast development of waste management both in Europe and developing countries. The CDM (Clean Development Mechanism) and JI (Joint Implementation) programmes under the Kyoto protocol also create new market potential in the waste management area. Within the limits of these mechanisms) the Annex I countries (industrialized countries and countries with economies in transition) can pay for projects that cut or avoid emissions in other countries and are awarded with credits that can be applied to meeting their own emission targets. The aim of the project was to estimate the market potential and greenhouse gas emission reduction potential of new waste management concepts. Several potential concepts in the following waste management sectors were included in the study: processing of waste into new products, treatment and utilisation of biowaste, energy production from waste and landfill disposal. In addition to the technical feasibility and emission reduction potential of the most significant technological alternatives, the economic feasibility of a few selected concepts for CDM or JI projects was analyzed. Based on case studies, landfill gas collection and flaring, as well as, with certain preconditions, production of biogas and production of energy from waste, are generally the most cost-effective alternatives in the projects under Kyoto mechanisms. Production of biogas from agricultural waste and sludge, as well as from other biodegradable sludge, is often more feasible in CDM and JI projects than production of biogas from source-separated biological fraction of municipal waste. Because of the crediting and the assumed short crediting period (five year Kyoto period), the projects producing a rapid emission reduction with a small investment proved in case studies to be economically most feasible. In this respect the Kyoto projects differ from other waste management projects where, in many cases, the investment in waste incineration or energy production from collected landfill gas turns out to be a cost-effective greenhouse gas reduction method. In this project, each waste management concept was studied as a separate system. In practice, the organization of the whole waste management system and the starting values of calculations may significantly impact the greenhouse gas reduction efficiency of newly introduced measures. This was shown especially in the case studies on material recovery, where life cycle assessment methodology was used in the comparison of the greenhouse gas emissions of a product produced from recycled material with those of a corresponding product made from virgin material. The most significant factors that influenced the results were the product used in the comparison, the method used for processing the waste material and what happened to the product after use. For example, in the comparison of a plastic profile made from recovered plastics with a conventional impregnated wood structure, the reduction of greenhouse emissions depended on whether the products were combusted or sent to a landfill at the end of their life cycle. The results could be different if the virgin product used in comparison was made from a fossil based material. Copyright © VTT 2007.