Berk. Penel. Hayati Edisi Khusus: 7F (41–45), 2011

FEASIBILITY OF LANDFILL GAS UTILIZATION FOR POWER PLANT: A CASE STUDY IN - EAST

Zamzami Septiropa* dan Sunarto Lecturer of Dept. of Civil Engineering UMM, member of CEERD UMM *Corresponding author: [email protected]

ABSTRACT Landfi ll gas is a renewable that can be used as alternative energy to generate power turbine. If all of the big cities in produce garbage 10 million ton/year, the electricity produced is 79 MW. To estimate the gas production at a landfi ll can be used model equation developed by Avfalzorg.NL. This study took the case in Supit Urang landfi ll Malang city with an average waste generation of approximately 400 ton per day. For the case in landfi ll Supit Urang Malang, the electricity generated can reach 855 KWh. From calculation with such capacity, the construction of landfi ll gas power plants will reduce total emissions until 129,356.25 ton carbon. It is equivalent with direct reduction 113,853.49 tons carbon the other side indirect reduction reduces 15502.75 tons carbon. Total carbon reduction is equivalent to the emission released by more than 25,000 vehicle.

Key words: Energy, Landfi ll gas, and Waste

INTRODUCTION the power supplies only 422 MW peak load reaches 417 MW. Based on data submitted by the Minister of Energy The use of methane gas from landfi ll as the driving and Mineral Resources, the areas that do not have backup turbine power plant actually is not new in the world, power supplies system are Northern Sumatera, Southern particularly in developed countries like USA, Australia, , Mahakam, Minahasa, and . The 14 Canada, and several countries in Europe. In the USA, until regions throughout Indonesia system only two regions is July 2007 there are 427 landfi ll gas power plants already expressed in normal status, i.e. the Java-Bali system and operating with a total capacity of 1260 MW. In Britain, the Southern system. use of this type has been stepped on the gas in the 15th with With the condition of the electric energy crisis and a capacity of 400 MW. Some developing countries have in line with world oil prices skyrocketing to almost 100 also been utilizing the energy potential of landfi ll methane U.S. $ per barrel and declining reserves of fossil energy gas, such as , India and Bangladesh. resources, the utilization of new and renewable energy While in Indonesia the use of landfi ll methane gas as sources to supplement the energy supply capacity should a new power plant largely limited to such proposal and be enhanced. Data from the Ministry of Energy and Mineral the feasibility study on the landfi ll in , landfi ll in Resources (Table 1) (Yusgiantoro, 2006), shows only a , and landfi ll in Palu, and another landfi ll in 10 small proportion of potential renewable energy sources that cities in Indonesia including landfi ll Supit Urang Malang. have been exploited in 2005. New hydropower installed Some projects capture methane gas for power plants that 4.2 GW (5.55%) from 75.67 GW potential. Energy biomass/ process of early development projects in the landfi ll are biogas from the landfi ll installed 0.3 GW (0.06%) from Suwung Bali by PT. Navigat Organic Energy Indonesia and 49.81 GW potential. landfi ll by PT Gikoko Kogyo Indonesia. In accordance with Presidential Regulation Number During the year 2007 until now, discussion about 5/2006, for the optimization of energy management, the methane as a source of alternative energy power plants Ministry of Energy and Mineral Resources in 2025 will in various seminars and mass media are relatively more target the use of new renewable energy sources by 17%, frequent. At least there are two reasons, i.e. the issue of much larger than the condition in 2005 (4.43%). The use of electrical energy crisis and global warming issues. Currently fossil energy (petroleum and coal) is targeted by 53%, going almost all regions in the country are still experiencing a down from the condition in 2005 amounted to 77%. crisis of power supply such as North Sumatra and West Decreasing use of fossil fuel will indirectly reduce Kalimantan. The worst power shortage is happened at South carbon dioxide emissions, one of the greenhouse gases . The installed capacity of 624 MW otherwise 42 Feasibility of Landfi ll Gas Utilization for Power Plant

Tabel 1. Potential Renewable Resources

Type of Energy Potential Equal Capacity Apply Hydro 845.00 million BOE 75.67 GW 4.2 GW Geo thermal 219.00 million BOE 27.00 GW 0.8 GW Mini/Micro Hydro 0.45 GW 0.45 GW 0.084 GW Biomass 49.81 GW 49.81 GW 0.3 GW Solar Cell - 4.80 kWh/m2/day 0.008 GW Win 9.29 GW 9.29 GW 0.0005 GW Source: Yusgiantoro, 2006 that causes global warming. Approximately 63% of carbon and air temperature in Indonesia are relatively high, then dioxide emissions are generated by energy sector (power the process of waste decomposition will take place more plants/oil refi neries) and the transport sector. quickly than other country (Purwasasmita, 2005). Directly, capture methane gas will reduce emissions In addition, organic matter content is very large, of methane gas that had been freely released into the therefore increasing of volume waste. Waste was produced atmosphere because one of the emissions that cause global by the cities in Indonesia reached 55,000 tons per day. warming is methane (CH4), which has a share of 18%, the However, only about 50% or 60% of the waste was collected second largest after the gas carbon dioxide CO2 (50%). and transported to landfi ll. The collected waste in major However, methane gas causing the greenhouse gas effect cities in Indonesia reached around 10 million tons per 3 is 21 times greater than CO2. year. Malang City itself produces 1,500 m /day waste or Methane Gas is renewable energy that replaces fossil 600 tons/day. fuels. According Environmental Protection Agency (EPA) Methane gas capture technology is applied in most of U.S, methane gas power plants with capacity of 1 MW the landfi ll in Indonesia. Moreover, most of the handling landfi ll directly will reduce nearly 2,000 tons of methane of waste in landfi ll in big cities in Indonesia is transported gas emissions each year than when the landfi ll methane and accumulated (58.7%) either with the system opens gas is not free regardless arrested. Indirectly Methane will dumping or controlling landfi lls. Waste processing, such reduce about 5,500 tons of carbon dioxide per year because as: composting technology (processing organic waste into the plant does not use fossil fuels. fertilizer), incineration (burning waste in incinerators), and Landfi ll methane gas or Final Disposal Site (TPA) is recycling (recycling) have been implemented in some cities, produced along the process of decomposition of organic but it was not running maximum due to various constraints waste by anaerobic bacteria in landfill waste. Waste (Kamaluddin, 2007). generated in Indonesian cities has a great potential to Infestation at Indonesia has an opportunity to obtain produce methane gas as largely composed of organic waste. carbon credits from Clean Development Mechanism (CDM) This is because the pattern of everyday life of Indonesian project landfill management through the utilization of society in general is still based on agricultural products so landfi ll methane gas for fl are or to generate electricity. If that the waste cities in Indonesia are typically dominated the production of waste in urban areas in Indonesia reached by type of household organic waste like food scraps and 10 million tons of waste per year, the potential methane vegetables that contain microbes such as bacteria, fungi, emissions from landfi ll waste reach 404 million m3 per year Actinomycetes and aptogen. and this energy can be converted into the equivalent of 79 The average composition of municipal waste in MW of electricity (Morton, 2005). The revenue from carbon Indonesia consists of: 74% of organic waste, paper 10%, fi nance can be reached Rp. 118 billion per year. 8% plastic, glass cups 2%, 2% metal, cloth and leather 2%, and others 2% (Purwasasmita, 2005). It is estimated that MATERIALS AND METHODS within two decades, this composition is still to be 60–75% The data of material ad methode take from case of range in the percentage of organic waste to landfi ll waste TPA Supit Urang Malang, with the volume accumulation from 0.50 to 0.67 kg/person/day and density 200 kg/m3 of 400 tons per day then the amount of waste in time, (Purwasasmita, 2005). Because conditions of humidity t = 5 years. Zamzami Septiropa dan Sunarto 43

To estimate the gas production at a landfi ll can be used electricity generated amounted to 855 kW. So for the case model equations developed by Afvalzorg. NL (Jacobs J, in landfi ll Supit Urang Malang, the electricity generated 2006). can reach 855 KWh. In general, the growth of methane gas describe in αt = ς1.87 AC k e–k1t (1) 0 1 Figure1, where in the begining will be seen very rapid Where: growth will decline further in accodance with the time α 3 -1 t = landfi ll gas production at a given time (m LFG.y ) (Jacob J, 2006). ς = dissimilation factor (0.58) 1.87 = conversion factor (m3LFG.kgC degraded-1) DISCUSSION A = amount of waste in place (Mg) -1 Co = amount of organic carbon in waste (kg C.Mg waste ) (see Landfi ll gas can be collected passively or actively. Table 2) Passive ccollected usually intended to capture and collect -1 k1 = degradation rate constant (0.094 y ) the gas which it will be released into the atmosphere or t = time elapsed since depositing(y) burned (fl are) so that the explosion at the landfi ll waste could be prevented. Either passively or actively, landfi ll Table 2. Content of Organic Material methane gas capture is done by installing a series of Organic carbon content Waste category collector wells or extraction wells made of pipe into the (kgC.Mg–1) heap of garbage that has been given a cover. Illustration Contaminated soil 11 of gas extraction wells are passive (Figure 2) and active Construction & demolition waste 11 Shredder waste 130 (Figure 3). Street cleansing waste 90 Horizontal pipes beneath with cover layer and below Sewage sludge & compost 90 the soil surface mounted. It uses as methane gas collector Coarse household waste 130 channel. The active method of fi shing, usually mounted Commercial waste 111 several vacuum pumps to drain and collect the gas. Some Household waste 130 characteristics of landfi ll gas capture method actively are Source: Jacobs J. (2006) (Jacobs J, 2006). • control valves on gas extraction wells to regulate RESULT pump

The case of TPA Supit Urang Malang, with the • The depth of extraction wells ranges from 50% to 90% volume accumulation of 400 tons per day (Bapeko Kota depth of landfi ll waste

Malang,2008) then the amount of waste in time, t = 5 • extraction wells made of iron pipe or plastic pipe years: • The number and spacing of each well depending on A = 400 ton × (5 th × 365 hari) = 730,000 ton depth, density, pressure, humidity and gas levels. If Co = 130 production of gas per year (see Table 2): Therefore Gas Production,

αt = 0.58 × 1.87 × 730,000 × 130 × 0.094 e - 0.0945 = 6,047,074 m3/year Electricity that can be generated from landfi ll methane gas produced can be estimated as follows: methane gas calorifi c value of 33,810 kJ/m3(Maaskant, 2006) and if 50% of landfi ll gas is methane, then the calorifi c value 16,905 kJ/ m3. Within one year has resulted in 6,047,074 m3 of landfi ll gas or 690 m3 per hour, heating capacity per hour is: Heating capacity = 16,905 kJ/m3 × 690 m3 = 11,664,450 kJ

If the assumed turbine generator requires 13,650 kJ Figure 1. Model Gas Production of Landfill (first order model) to produce 1 kilowatt (KW) (Maaskant W, 2006), the (Jacobs J, 2006) 44 Feasibility of Landfi ll Gas Utilization for Power Plant

Figure 2. Passive Methane Gas Capture on the Landfill (Jacobs J, 2006)

Figure 4. Capturing methane gas pipeline (Jacobs J, 2006)

Gas is channeled through pipe is controlled by the valves. It regulates gas fl ow and take samples of gas. Sampling is necessary to know how much gas is produced, composition, and gas pressure. This data was used to adjust the valves controlling the pump. Gas is collected then goes through the process of fi ltering and purifying it before burning to drive the gas turbine power plant (Figure 5).

The mechanisms of direct combustion (open fl aring) Figure 3. Active Methane Gas Capture on the Landfill (Jacobs are shown in Figure 6, is the simplest way to reduce the J, 2006) impact of global warming due to methane gas. Methane gas

which is burned into smaller effect of CO2 gas that is 1/21

Figure 5. Gas Collection System and Power Plant (Jacobs J, 2006) Zamzami Septiropa dan Sunarto 45

Figure 6. Open Flaring System (Jacobs J, 2006) compared with methane gas is not burned, left Just released Kamaluddin LM, 2007. Proyek Pengembangan Biogas di TPA into the atmosphere. Melalui Program CDM, Global Eco Rescue Foundation From calculation above with such capacity, the Ltd. construction of landfi ll gas power plants will reduce total Maaskant W, 2006. Global Warming and Landfi ll Gas Collection for Electricity, Workshop Kebersihan Kota Manajemen TPA emissions until 129,356.25 tons carbon. It is equivalent Kaitannya dengan Program CDM, UMM with direct reduction 113,853.49 tons carbon. Total carbon Morton J, 2005. World Bank Experience in Landfill Gas reduction is equivalent to the emissions released by more and Prospects for Indonesia, Workshop, Landfill Gas than 25,000 vehicle. Development and the CDM, Bali. Purwasasmita M, 2005. Solusi Tuntas Mengolah Sampah, REFERENCES http://turatea-berita.blogspot.com/2005/12/solusi-tuntas- mengolah-sampah.html Agency (EPA) U.S., - http://www.epa.gov. Yusgiantoro P, 2006. Peran Energi Terbarukan dalam Ketahanan Jacobs J, 2006. Landfi ll Management, Workshop Kebersihan Energi Nasional, Orasi Ilmiah Wisuda UMM. Kota Manajemen TPA Kaitannya dengan Program CDM, UMM