METHODS USED TO ESTIMATE THE GREENHOUSE GAS EMISSION POTENTIAL  FROM SOLID WASTE DISPOSAL

E. David^1*, N. Aldea², S. Preda³,  A. Armeanu¹, C. Sandru¹, F. Bucura¹, M. Constantinescu¹, D. Mocanu¹

¹National Institute for Research and Development for Cryogenic and Isotopic Technologies - ICIT Rm. Valcea, Uzinei Street no.4; P.O. Box 7 Râureni, 240050, Rm.Vâlcea, Romania

ABSTRACT

Environmental policy in waste management leads to increasing interest in developing methods for waste disposal with minimum emissions of greenhouse gases and minimum environmental impacts.Open dumping, landfilling and modern  waste combustors (MWCs)  are the prevalent solid waste disposal practices in many countries. Surveys on the disposal sites revealed the presence of numerous  landfills ,open dumps and waste combustors. Greenhouse gas emission potential at these sites can be estimated  by different  methods. The purpose of this paper is to establish a more robust technique for determining the potential of  gas emissions from municipal solid waste and to use those results in a life cycle assessments that determines the GHG impacts of modern MWCs and landfills. Methane emission potential at these sites was estimated by three methods. Results of the Intergovernmental Panel on Climate Change (IPCC) method, Landfill Gas Emission model (LandGEM), and closed flux chamber technique were compared. For the facilities analyzed , the methane emission potential of 18.94 Gg/yr using the IPCC method was higher than the estimations of the LandGEM and closed flux chamber method of 5.95 Gg/yr and 5.33 Gg/yr, respectively. From the point of view of nitrous oxide (N₂O) emissions, waste incineration and waste co-combustion are  acceptable methods of waste disposal. Two factors are important for attaining  low NOx emissions from waste  combustion , particularly for waste with higher nitrogen content (e.g. sewage sludge, leather, etc.): temperature of incineration over 900^OC and  using  of modern  incinerators with selective catalytic reduction (SCR) or selective noncatalytic reduction (SNCR) deNOx  facilities. The catalysts used  in SCR based facilities are among others Fe-zeolite and V₂O₂.This catalysts have high N₂O decomposition (and SCR) activity with good hydrothermal stability.This data are essential to assess the potential  need of abatement measures to limit N₂O emissions in future operation of waste incineration plants.  

 KEYWORDS: MSW, CH4 , NOx emission, landfill, open dump, incineration, selective catalytic reduction (SCR)