Glossary of Terms Term Meaning Greenhouse gas (GHG) Gas in an atmosphere that absorbs and radiation within the thermal infrared range. Major GHGs from waste management are carbon dioxide (CO2), methane (CH4), and nitrous dioxide (N2O). Short Lived Climate Pollutants (SLCP) Short-lived climate pollutants (SLCPs) are agents that have relatively short lifetime in the atmosphere - a few days to a few decades - and a warming influence on climate. The main SLCPs emissions from waste management are black carbon (BC), methane (CH4). (BAU) The normal performance of standard functional operations. Refuse Derived Fuel (RDF) A solid fuel derived from waste, which can be used as a fuel product either in an on-site combustion facility or by a third-party user such as cement kilns or power stations. Black Carbon (BC) Black carbon (BC) is a major component of soot and is produced by incomplete combustion of fossil fuel and biomass Global Warming Potential (GWP) The global warming potential (GWP) of a gas refers to the total contribution to global warming resulting from the emission of one unit of that gas relative to one unit of the reference gas, CO2 which is assigned a value of 1 Life Cycle Assessment (LCA) Life Cycle Assessment (LCA) is a tool/method for the systematic evaluation of the environmental aspects of a product or service system through all stages of its life cycle.
Degradable Organic Carbon(DOC) Degradable organic carbon (DOC) is one of the main parameters affecting the CH4 emissions from solid waste disposal Methane generation rate constant (k) Model constant that determines the estimated rate at which waste decays and generates LFG Methane Correction Factor (MCF) Adjustment to model estimates of LFG generation that accounts for the degree to which waste decays anaerobically
However, some cities may not have the detailed information required for such calculations. Therefore, default data has been provided by the developer based on available information in the literature. The types of default values provided in each sheet and the reference sources are provided in Table 1 below. Table 1: Default values and emission factors used in the tool Name of the sheet Description of the default value Reference source Key data Climatic zones of the countries Moist and Wet Tropical = Mean Annual Precipitation (MAP) ≥ 1000 mm Dry Tropical = Mean Annual Precipitation (MAP) < 1000 mm Dry Temperate = Mean Annual Precipitation (MAP)/Potential Evapotranspiration (PET) <1 Wet Temperate = Mean Annual Precipitation (MAP)/Potential Evapotranspiration (PET) >1 IPCC, 2014 Economic level of the countries (1) Lower-income -Gross National Income (GNI) per capita- $1,045 or less, (2) GNI per capita $1,045-$4,125 (3) Lower-middle-income GNI per capita (4) High income- GNI per capita $12,746 or more The World Bank, 2013 Per capita generation rate for different economic level Lower income -0.6; Lower middle income -0.78; Upper middle income-1.16; High income-2.13 (kg/capita/day) The Bank, 2013 collection rate based on the development level of the country Low income countries < 50%; Middle income countries 50-80%; High income countries > 90% The World Bank, 2012 composition data based on the region IPCC, 2006 c Emission Factors for grid electricity production (The values cannot be presented here as it is a long list) IGES, 2014; Ecometrica, 2011 Calorific values of fossil fuel IPCC,2006 d Staffell, 2011 Transportation Fossil fuel and grid electricity consumption rate at transfer station Electricity consumption – 2.5 kWh/tonne Diesel fuel consumption -0.125 L/tonne Diaz,R. and Warith,M. 2006 Black Carbon (BC) emission factor from different type of vehicles Both modern and older g/kg of fuel; Modern trucks -0.47 g/kg of fuel; Older trucks - 2.39 g/kg of fuel Bond et al. 2013
Some cities may have transfer stations for proper handling, sorting and management of collected waste. This sheet would thus support the quantification of emissions from the transfer stations. Users are asked to provide the total amount of waste handled at the transfer station (note that not all the waste collected by the city may reach the transfer station). In addition, data should provide on utilisation fossil fuel and grid electricity for operational activities. In the absence of such data, default values provided by the developer can be utilised. The estimation method of emissions is presented in Box 1. The results will be displayed in the same sheet in which emissions have been calculated per gas, taking into account life cycle phases. All default values and emission factors used in this calculation are listed in Table 1. The structure of the page is shown in Figure 9. Figure 9: Print screen view of transportation sheet 2.3 Selection of technologies for treating the separated waste fractions Some organic waste and/or recyclables are separated at the household level or at material recovery facilities. The separated organic waste can be treated using composting and AD technologies while the separated different types of recyclables can be recycled for recovery of materials. In this tool, separate sheets have been designed for the above technologies to quantify the emissions from separated organic waste and recyclables. Users should provide data in those individual sheets if they have chosen any of those technologies in BAU or intended scenarios. The detailed specifications of composting, AD and recycling sheets are described in the sections below.
recovery’ option the user can leave cells empty in the ‘Specifications of Landfill-gas recovery session. Although the sanitary landfill with gas recovery option may exist without an energy recovery system, the user can still leave the cells empty. However, landfill gas flaring may be the option in the case of ‘No energy recovery’ choice from sanitary landfill with gas recovery. Flaring would create particulate matter (PM) in the form of BC. However, currently available emissions quantification methods would not be sufficient to quantify BC emissions from landfill gas flaring and these estimations needs to be included in the future. The basic concept used in the IPCC 2006 Waste Model has been adopted in this tool to quantify CH4 emissions from different types of landfills. The guidelines of IPCC strongly encourage the use of the First Order Decay (FOD) model, which produces more accurate emissions estimates as it reflects the degradation rate of wastes in a disposal site (IPCC 2006). The model assumes that decomposition in the first year can happen aerobically where CH4 generation is not taking place. In addition, other GHGs and BC emissions will be estimated based on the fossil energy and grid electricity consumption for operational activities. The step-by-step procedure for calculation of GHG/SLCP emissions from landfill/open dump technologies is shown in Box 7. Box 7: Method of estimating GHG/SLCP emissions from landfilling/open dumping