Analysis of Palm Biomass as Electricity from Palm Oil Mills in North Sumatera

Available online at www.sciencedirect.com

ScienceDirect Energy Procedia 47 (2014) 166 – 172

Conference and Exhibition Indonesia Renewable Energy & Energy Conservation [Indonesia EBTKE CONEX 2013]

Analysis of Palm Biomass as Electricity from Palm Oil Mills in North Sumatera Muhammad Ansori Nasutiona,*, Tjahjono Herawana, Meta Rivania a

Indonesian Oil Palm Research Institute (IOPRI), Jalan Brigjen Katamso 51, Medan 20158, Indonesia

Abstract Empty fruit bunch, shell, and fiber are palm biomass waste that can be converted to energy by cogeneration system. On the other hand, electricity shortages severely hampered the development of North Sumatera. Therefore, the objective of this paper is to present a potential analysis of palm biomass waste in generating electricity by palm oil mills in North Sumatera. Some palm oil mills in North Sumatera were analyzed in electric potential by using collected data, questionnaires and interviews. The results show that a POM with 30 tones FFB/hour generates at least 20 MW (20 MW to 35 MW). © 2014 2014The TheAuthors. Authors. Published Elsevier © Published by by Elsevier Ltd.Ltd. Selectionand andpeer-review peer-review under responsibility ofScientific the Scientific Committee of Indonesia Conex 2013. Selection under responsibility of the Committee of Indonesia EBTKEEBTKE Conex 2013 Keywords: renewable energy; palm biomass; electricity; palm oil mill; North Sumatera

Nomenclature CPO EFB FFB GHG GPS kJ kW MW MJ POM

Crude Palm Oil Empty Fruit Bunch Fresh Fruit Bunch Green House gases Global Positioning System kilo Joule kilo Watt Mega Watt Mega Joule Palm oil Mill

* Corresponding author. Tel.: +62-61-7862477; fax : +62-61-7862488 E-mail address: [email protected]

1876-6102 © 2014 The Authors. Published by Elsevier Ltd.

Selection and peer-review under responsibility of the Scientific Committee of Indonesia EBTKE Conex 2013 doi:10.1016/j.egypro.2014.01.210

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1. Introduction Palm oil is currently the world’s largest source of edible oil. POM in Indonesia produces about 23 MT crude CPO or 46% of the total world palm oil producing in 2011 [1]. It is predicted that the demand of world palm oil will remain increase as followed by population growth, food and chemical industrialized. More CPO produced is more palm biomass wastes. A POM wastes around 12 to 15% fiber, 5 to 7% shell, and 20 to 23% EFB based on its capacity. However, this biomass waste is needed to be utilized effectively to overcome its disposal problem since environmental concern today. Palm biomass have been long identified and utilized as renewable energy but there is rare energy power plant applied. The Government of Indonesia has taken steps with this concept with the National Energy Policy in 2006 that is aimed to increase biomass based energy to 5% by 2025. Nowadays, converting POM waste into energy is supposed by Protocol Kyoto with the objective of reducing GHG emissions [2]. Actually, POM is applying a cogeneration system in producing steam and electricity demand in the milling process by using one source of fuel [3, 4]. Cogeneration system consists of boiler, turbine, and generator [3]. Fiber and shell (70:30) are burnt directly in boiler to form saturated or superheated steam. A half of the steam is used for milling process such as sterilization, kernel storage, etc. Residual steam is converted to electricity by using a turbine. EFB is not commonly fed as fuel because it contains high moisture content. EFB is usually applied for mulching in oil palm plantation or compost even though EFB transportation is related to the environmental aspects. However, fiber, shell and EFB have a high caloric value that can be utilized as an energy source for useful purpose. Heat and power generated by cogeneration is more than sufficient for milling process of POM. On the other hand, POM miller needs to reduce palm biomass waste. Due to that many POM burnt more biomass waste to obtain more energy that not only use for milling process but also distribute it excess electricity to employee resident and local people. This delivery electricity concept can be applied to support electricity demand in North Sumatera by using national grid line as the distributing system. This paper describes a study analysis of electrical potential generated by palm biomass in North Sumatera. The analysis is useful for cluster power plant planning in North Sumatera. Others benefit of the study is to reduce GHG emissions risk, increase employment of local people and increase add value of palm oil plantation.

2. Material and method Some materials used are map, GPS, assessment questionnaire, and thermochemical data. Cogeneration data were collected from 21 representatives POM in North Sumatera. Data was obtained from assessment questionnaire, interview, laboratory sampling, GPS mapping. The data were used as a baseline data to calculate energy potential. Analyzing and calculating data used Excel® and it is represented by a graph and chart. x x x x x x x x

The scopes of study were: The distance from POM to the nearest grid line. Process capacity POM (ton FFB/hour) Quantity of POM biomass waste (ton/hour) Actual biomass used for boiler feed (ton/hour) Actual energy generated (MW) Energy consumption of a POM (kW) Potential electricity or energy generated (kW) Potential energy excess of a POM (kW)

The following assumptions or data were used in the calculation: x The process energy balance is started from boiler, turbine, accumulator, generator and grid line. x Caloric value for EFB, shell and fiber in dry basis are 18,838 kJ; 20,108 kJ; and 19,068 kJ [5,6]. x Steam enthalpy at 20 Bar, 260 oC = 2982 kJ/kg steam.

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x Boiler and generator efficiency are 70% and 70%. x POM energy consumption is 27 kWh/ton FFB and 0.55 to 0.60 ton steam/ton FFB [2,7]. 3. Results and discussion 3.1. POM capacity and distance to the national grid line Actually, there are about 83 POM detected by GPS in five districts of North Sumatera, that most are in Asahan and Labuhan Batu district. Then, those POM were selected by representative operating performance and distance between POM and the others in each district. Almost a half of the POM assessed in North Sumatera has 30 tons FFB/hour capacity. Others have higher capacity, 45, 50 and 60 tons FFB/hour. Only around 14% POM has less than 30 tons FFB/hour (Fig. 1). Generally, POM standard capacity is 30 and 45 tons FFB/hour. To up scaling the capacity, POM usually adjoins new operating units without fully change operating system. <30 ton FFB/h 14%

60 ton FFB/h 14% 50 ton FFB/h 14%

45 ton FFB/h 10%

30 ton FFB/h 48%

Fig. 1. Percentages of POM capacity in North Sumatera.

Distance is an important point in the electricity distributing system. The palm biomass power plant has not more than 10 km from POM to grid line [8]. A long distance will increase cost investment in the grid line and inefficient electricity distribution. The distance from POM to the national grid line is available in Fig 2. Most of POM is located not more than 1 km from the low voltage (71% POM) and medium voltage (48% POM) grid line.

Number of POMs (%)

80%

71%

low voltage

medium voltage

70% 48%

60% 50%

29%

40%

24%

19%

30%

10%

20% 10% 0% < 1 km

1-5 km

>5 km

Distance

Fig. 2. Percentage of POM based on the distances to the grid.

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A clustering of palm biomass power plant also needs close distance between POM and others. The distance is not more than 20 km. In North Sumatera, there are around 70% of POM assessed have 10 to 20 km distance from POM to others (Fig.3). A close distance from POM to grid line or to others POM shows that a clustering in producing electricity from palm biomass is possible in North Sumatera. 70%

Number of POM

60% 50% 40% 30% 20% 10% 0%

< 1 km

1-10 km

10-20 km

Fig. 3. Percentage of POM based on the distances to the others POM.

3.2. Palm biomass waste availability Theoretically, increasing of FFB processed, bigger palm biomass waste and lesser energy required. There will require an extra handling of waste that influences the cost. Three bar charts below describe composition of EFB, fiber and shell in the 21 POM assessed. Most POM have 20% EFB, 13% fiber and 7% shell by POM capacity (Fig. 4a, Fig. 4b and Fig. 4c). EFB is the biggest waste (20%) than fiber (14%) and shell (7%). Therefore, utilization EFB as the energy source gives an effect of the amount of energy produced and waste reduced. EFB 22% 14%

Fiber 14% 33%

EFB 23% 5%

EFB 20% 48%

Fiber 13% 67%

Fig. 4a. Composition of fiber at 21 POM assessed.

EFB 21% 33%

Fig. 4b. Composition of EFB at 21 POM assessed.

Shell 7% 52%

Shell 6% 43%

Shell 5% 5%

Fig. 4c. Composition of shell at 21 POM assessed.

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3.3. Actual energy Assessed POM utilizes fiber and shell as boiler feeding. POM burnt all fiber produced by milling process while there are a number of shells are not burnt to boiler. Some POM sells residual shell due to its good market price. However, excess electricity is still obtained without burning all shells produced. Actual electricity produced by POM based on collecting data is shown in Figure 5. All of POM assessed has similar condition such as residual shell is sold and no EFB utilization as boiler feeding. POM assessed generates around 3 to 20 MW electricity from palm biomass waste. A POM with 30 tons FFB/hour generates 8 to 12 MW and a bigger POM capacity must produce higher electricity. Actual energy excess without EFB utilization is available in Figure 6. There is around 9.7 kW/ton FFB excess energy that can be distributed to local people by grid line.

60 ton FFB/h 17-20 MW 14%

< 30 ton FFB/h 3-7 MW 14%

40-50 ton FFB/h 13-16 MW 24%

30 ton FFB/h 8-12 MW 48%

Fig. 5. Actual energy generated by POM assessed (based on biomass data and without EFB utilization).

Fig. 6. Energy excess of POM (without utilizing EFB).

However, there are some problems that can cause difference in energy produced. They are improper blending of fiber and shell, moisture content of materials, incomplete combustion and air flowing [7]. Another problem is steam quality. The presence of water in steam (wet steam) decreases generation efficiency. Some POM utilizes superheated steam to obtain high dryness steam. Steam produced by boiler is delivered to turbine. The steam turbine normally used in POM is one or two stage impulse with backpressure type.

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3.4. Potential energy Many researchers had reported that mulching and composting only can be applied for particular POM [2, 9]. Mulching and composting consume fuel for transport EFB and distribute it to the plantation. It is not only considerable with the cost but also CO2 emissions. The energy produced is higher than actual energy at POM if all of palm biomass waste is utilized as boiler feeding. Figure 7 shows that a POM with 30 tons FFB/hour generates electricity 20 to 25 MW. It is higher two times than without EFB utilization. It also gives a higher surplus of electricity, which is around 530 kW/ton FFB or 54 times higher than if without EFB utilization (Fig. 8). 30 ton FFB/h 20-25 MW 48%

< 30 ton FFB/h 8-15 MW 14%

40-50 ton FFB/h 30-36 MW 24%

60 ton FFB/h 41-43 MW 14%

Fig. 7. Energy potential generated by POM assessed (based on biomass data and with EFB utilization).

Fig. 8. Energy excess of potential energy of POM (with EFB utilization).

Nowadays, North Sumatera suffers electricity shortages that disturb its development and industrialized. A palm biomass power plant is a promising solution to overcome that the electricity shortage in due to North Sumatera has many palm oil industries. Some small POM capacity in one area of regency can supply their biomass waste to the power plant. The power plant employs cogeneration with proper and better unit specification to generate high electricity. This concept is called clustering energy. However, it requires a large investment but many advantages obtained, such as revenue, lower milling cost, environmental risk and support national electricity.

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4. Conclusion The study found that the current generation system generated lower electricity than its potential. Utilization of EFB as energy source produce around 530 kW/ton FFB energy excess or increase two times than no EFB utilization. Its high potential should be commercially exploited by national grid line distributing. Some POM in North Sumatera have energy potential and also meet the distance grid line requirement. However, utilization of palm biomass wastes support electricity demand in North Sumatera and contribute to the national energy based on renewable sources. Acknowledgements Authors are thankful to Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH Indonesia for research funds. References [1] Oil World. Statistics for 17 oils and fats, database 2011. Germany: Oil World; 2012. [2] Arrieta FRP, Teixeira FN, Yáñez E, Lora E, Castill E. Cogeneration potential in the Columbian palm oil industry: Three case studies. Biomass and Bioenergy 2007; 3:503-511. [3] Shuit SH, Tan KT, Lee KT, Kamaruddin AH. Oil palm biomass as a sustainable energy source : A Malaysia case study. Energy 2009; 34:1225-1235. [4] Goyal HB, Seal D, Saxena RC. Biofuel from thermochemical conversion of renewable resources : A review. Renewable Sustainable Energy Rev 2008; 12:504-517. [5] Nasrin AB, Ravi N, Lim WS, Choo YM, Fadzil AM. Assessment of the performance and potential export renewable energy (RE) from typical cogeneration plants used in palm oil mills. J. Eng. Applied Sci 2011; 6(6):433-439. [6] Vijaya S, Chow MC, Ma AN. Energy database of oil palm. Palm Oil Eng. Bull. 2004; 70:15-22. [7] Husain Z, Zainal ZA, Abdullah MZ. Analysis of biomass-residue-based cogeneration system in palm oil mills. Biomass and Bioenergy 2003; 24:117-124. [8] Yoon LC, Iwata T, Shimada S. System analysis for effective use of palm oil waste as energy resources. Biomass and Bioenergy 2011; 35:2925-2935. [9] Danida RE/EE. A Malaysian Danish environment cooperation programme. Renewable energy and energy efficiency component. Barrier analysis for the supply chain of palm oil processing biomass (Empty Fruit Bunch) as renewable fuel integrated resource planning 2. Malaysia; 2006.