Comparison of Potential Greenhouse Gas Emission ...

Proceedings of the 6th ACEC and the 6th AEEC

21-22 November 2013, Bangkok, Thailand

Comparison of Potential Greenhouse Gas Emission from Municipal Solid Waste Disposal Site in Savannakhet and Champasak, Lao PDR Xaysackda Vilaysouk and Sandhya Babel School of Biochemical Engineering and Technology, Sirindhorn International Institute of Technology, Thammasat University, Pathum Thani, Thailand, Tel: +66 2986 9009 Ext. 2307, Fax: + 66 2986 9009 Ext. 2301, E-mail: [email protected], [email protected]

Abstract Municipal solid waste (MSW) disposal is the most popular method for MSW in least developed countries together with developing countries as this is cheap and requires less professional skills. It contributes to 3% of global greenhouse gas (GHG) emission. GHG emission in MSW disposal site (MSWDS) is dependent on the characteristics and disposal method of MSW. GHG emission from MSWDS was investigated and compared at two locations in Lao PDR, Savannakhet (SVK) as representative of special economic zone and, Champasak (CPS) as representative of agriculture producer and local trading hub in southern region. International Panel on Climate Change (IPCC) 2006 model was used to estimate the potential emission of GHG from MSWDS. The MSW data used in this study were based on secondary data from Institute for Global Environmental Strategies (IGES) report 2012. Only methane (CH4) was considered in this study. MSWDS at these two locations are simple and unmanaged. Results of study indicated that the composition of waste and type of MSWDS influences potential of CH4 emission. The potential of CH4 emission in CPS was higher compared to SVK as CPS contained 8% more biodegradable material than SVK. Total CH4 emission from existing MSW management in SVK and CPS were 326 Gg/year and 241 Gg/year, respectively. Four alternative scenarios are developed considering environmental protection and GHG reduction. Scenario S4, which assumes 50% of compostable and recyclable materials sent to composting and recycling process, could reduce approximately 43-44% of total CH4 emission compared to baseline scenario S0. Considering the biodegradable composition in SVK and CPS, composting process is the most applicable approach that needs to be integrated in MSW management. This will reduce the amount of waste that is disposed on landfill, reduce GHG emission and protect the environment. Keywords: GHG emission, Municipal solid waste disposal, Composting, Recycle, IPCC Model.

1. Introduction Municipal solid waste management (MSWM) is considered as significant problem in many developing countries as well as developed countries [1-3]. Growth of population, urbanization and development of economy as well as improvement of living standard in the city has increased the amount of MSW around the world [2-5]. In developed countries, typically MSW generation rate places between 521.95–759.2 kg/person/year, and 109.5– 525.6 kg/person/year in developing countries [4]. According to recent study, municipality around the world generated approximately 1.3 billion tonnes of MSW and it is expected to increase to 2.2 billion tonnes in 2025 [6]. Disposal on landfill is the most common method of managing MSW in least developed countries and developing countries as this method is cheap and requires less professional skills. GHG emission from MSW sector contributes to

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approximately 3% of global GHG emission [7]. GHG emission in MSWDS is mainly dependent on the composition of MSW and disposal method [8]. MSWM is a new perception for Lao people. For last few decades, life style of Lao people was simple, produced small amount of waste and mostly was organic fraction that could be naturally degraded [9]. Nowadays, MSW in Lao PDR is increasing dramatically due to increase in population and economic development [10]. In 2004, annually MSW in a whole country was 270,000 tonnes and average generation rate of waste was 0.75 kg/capita/day [10]. Lao PDR does not have the clear legal framework and strategy for dealing with MSW [9-12]. The country report of April 2012 highlights the current situation of MSWM in Lao PDR. The difficulties that are currently faced are lacking of: landfill site, hazardous waste disposal facility, guideline for efficient use of agricultural waste, rules for management of municipal solid waste, incentives for environmental management system and cleaner production, public cooperation, institutional capacity, financial and human resources, MSW database and recording system [12]. There are few studies conducted in Lao PDR related to MSW. The study on existing MSWM in Lao PDR needs to be carried out to protect environment and reduce GHG emission. This study investigates potential GHG emission from MSWDS in two locations in Lao PDR. It compares GHG emission between two locations and influence of characteristics of MSW and management method on GHG emission. Taking into consideration the reduction of GHG emission, different options of MSW are proposed in this study for two locations.

2. Methodology 2.1 Municipal Solid Waste in Savannakhet (SVK) Savannakhet (SVK) was selected for this study as representative of special economic zone province in Lao PDR [13, 14]. SVK is located in East-West Economic corridor of Greater Mekong Sub region, linking Vietnam, Lao PDR, Thailand and Burma [15]. Savan-Seno Special Economic Zone (SSEZ) has started developing since 2003, and the categories of business activities planned to be developed in the SSEZ include export-processing zone, free trade zone, free service and logistic center [13, 14]. MSW generation is affected due to increase in population and development of economic activities. In 2002, the MSW generation rate was 1.0 kg/capita/day and approximately 18-20 tonnes/day of MSW was sent to MSWDS [10]. By the year 2008, the MSW generation rate decreased to 0.64 kg/capita/day, but amount of MSW was sent to MSWDS increased to approximately 29.45 tonnes/day (Table 1) [9]. The disposal method of MSW in SVK is mainly landfilling. Approximately 70% of total MSW generated was sent to MSWDS. Disposal site is simple and unmanaged [9]. Figure 1(a) shows the composition of MSW in SVK. It can be seen that biodegradable waste (food waste, garden waste, paper, leather) comprise 80% of the total MSW followed by plastic 15%, glass 2%, metal 1% and other waste 2%, respectively. 2.2 Municipal Solid Waste in Champasak (CPS) Champasak (CPS) province is located in the southern Lao PDR. It shares border to Saravanh province in the north, to Cambodia in the south, to Attapue province in the east, to Sekong province in the northeast and to Thailand in the west. The main economy activities in CPS are agriculture. It is a trading hub in southern region of Lao PDR linking Lao PDR with Thailand, Vietnam and Cambodia. In terms of tourism sector, in 2011 CPS had 195 tourist sites. In 2009, CPS population reached to 643,686 compared to 890,582 in SVK [16].

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21-22 22 November 2013, Bangkok, Thailand

CPS municipality started running the first MSWDS in 2000. Site area is 13.5 ha with 2.2 ha disposal area. This land landfill has only 5 years of lifespan [10].. Common practice for MSW disposal in CPS is landfilling, and about 21.45 tonnes/day or 42% % of total MSW generated (Table 1) [9] wass sent to MSWDS in year 2008. The The rest was illegal dumping or open burning in backyard and some amount was sent to recycling process. According to previous study [9] in 2008, MSW generation rate was 0.7 kg/capita/day kg/capita/day and total amount of MSW was 51 tonnes/day. Figure 1(b) presents the composition of MSW at landfill in CPS. Maximum aximum portion of total MSW is food waste (62%), followed by 21% garden waste. Table 1 shows the MSW generation rate at two places. Data in Figure 1 and Table 1 are from different years due to unavailability of data. Glass Metal Other 2% 1% 2% Plastic 15% Food Waste 54%

Textile 1%

Plastic 6% Textile 1%

Metal Other Glass 3% 2% 1%

Food Waste 62%

Paper 4%

Paper 9% Garden Waste 16%

Garden Waste 21% (a) Municipal solid waste composition of Savannakhet

(b) Municipal solid waste composition of Champasak

Source: Sang-Arun, Arun, J., & Pasomsouk, K. (2012) (2012 [9] Figure 1.. Municipal solid waste composition of study area Table 1. MSW Information in SVK and CPS Parameters Population MSW Generation Rate (kg/capita) Total MSW Generated (tonne/day /day) MSW disposed at MSWDS (ton (tonne/day) Source: Sang-Arun, Arun, J., & Pasomsouk, K. (2008) (20 [9]

Location SVK CPS 65,724 72,955 0.64 0.70 42.07 51.07 29.45 (70%) 21.45 (42%)

2.3 IPCC 2006 Model for GHG Emission Calculation from Solid Waste Disposal Site The 2006 International Panel anel on Climate Change Guidelines for National Greenhouse Gas Inventory (IPCC 2006) model is primarily used in this study. The IPCC 2006 model is the principally and internationally nally agreed model used by many countries to report national GHG inventory to the United Nations Framework Convention on Climate Change [8]. IPCC 2006 model calculation culation covers the following GHG emission such as: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulphur hexafluoride (SF6), nitrogen trifluoride (NF3),

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trifluoromethyl sulphur pentafluoride (SF5CF3), halogenated ethers (e.g.,C4F9OC2H5, CHF2OCF2OC2F4OCHF2, CHF2OCF2OCHF2) and other halocarbons not covered by the Montreal Protocol including CF3I, CH2Br2 CHCl3, CH3Cl, CH2Cl2 [8]. Estimation of GHG from solid waste disposal site (SWDS) in IPCC 2006 model is based on the First Order Decay (FOD) method. FOD method assumes that the degradable materials in SWDS are decomposed slowly through the time. Based on laboratory work and field observation on CH4 generation from SWDS data, it is suggested that the overall decomposition process of degradable material could be approximated by FOD method and this has been widely accepted [8]. If the condition of SWDS is constant, CH4 generation rate will uniquely depend on the amount of degradable material remaining in SWDS, It would be higher in the first few years, and then it would decrease due to decrease in degradable material remaining. The decomposition of degradable material in SWDS produces significant amount of CH4 and also some amount of biogenic carbon dioxide (CO2), non-methane volatile organic compounds (NMVOCs) as well as smaller amounts of nitrous oxide (N2O), nitrogen oxides (NOx) and carbon monoxide (CO) [8]. There are 3 hierarchies for GHG emission calculation from MSWDS in IPCC 2006 model [8] as describe below:  Tier 1: “ The estimations of the Tier 1 methods are based on the IPCC FOD method using mainly default activity data and default parameters. ”  Tier 2: “ Tier 2 methods use the IPCC FOD method and some default parameters, but require good quality country-specific activity data on current and historical waste disposal at SWDS. Historical waste disposal data for 10 years or more should be based on country-specific statistics, surveys or other similar sources. Data are needed on amounts disposed at the SWDS. ”  Tier 3: “Tier 3 methods are based on the use of good quality country-specific activity data (see Tier 2) and the use of either the FOD method with nationally developed key parameters, or measurement derived country-specific parameters. Key parameters should include the half-life time, and either methane generation potential (L0) or DOC content in waste and the fraction of DOC which decomposes (DOCf). ” In this study, based on the availability of the MSW data in the study area, Tier 1 is used for estimating the CH4 potential emission. Only CH4 emission was considered in this study because CO2 and N2O are negligible due to small amount of gas produced in small landfills as in CPS and SVK. Equation (1) was modified from IPCC 2006 model Tier 1 to adapt with the available data. CH4 Potential Emission Rate (Gg CH4 /Gg MSW) = MCF×DOC×DOCF ×F× 16 12 (1) Where MCF is CH4 correction factor for aerobic decomposition, DOC is fraction of degradable organic carbon in MSW (Gg C/Gg MSW), DOCf is fraction of DOC that can decompose (fraction), F is fraction of CH4 in generated landfill gas (volume fraction), 16/12 is molecular weight ratio CH4/C. 2.3.1 Methane Correction Factor (MCF): According to IPCC 2006, for calculation of CH4 emission from MSWDS, disposal sites are classified into four categories (Table 2). The CH4 emission in managed MSWDS is higher compared to unmanaged MSWDS. The decomposition process in unmanaged MSWDS is mostly in aerobic condition with less CH4 emission; in opposite way the decomposition in managed MSWDS is anaerobic condition, which produces more CH4 [8].

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Table 2. SWDS Classification and Methane Correction Factor (MCF) Type of SWDS Managed – anaerobic Managed – semi anaerobic Unmanaged – deep (5m > waste) or high water table Unmanaged – shallow (5m