Life cycle energy efficiency and potentials of biodiesel production from palm oil in Thailand
Introduction
During this energy crisis, record high prices of crude oil and environmental concerns have driven the Thai government to set its national energy policy with an emphasis on renewable energy such as biodiesel and bioethanol in order to reduce fossil fuel consumption and to increase the energy security of the country. Besides, the Ministry of Energy has forced a mandatory measure on “B2” biodiesel (2% of B100) instead of conventional diesel fuel effective from 1 February 2008. This measure encourages the use of about 1.2 million liters of biodiesel a day. In Thailand, palm oil is a biomass resource which has high potential as a renewable energy source for biodiesel (B100 or palm oil methyl ester, PME) production. In addition, the low heating value (LHV) of PME is quite comparable to that of diesel (35.5 MJ/L for PME compared to 38 MJ/L for diesel) and a potential decrease in the greenhouse gases by PME use makes it more interesting (Demirbas, 2007). The crude palm oil (CPO) yield from palm fruit is approximately 180 kg per ton fresh fruit bunch (FFB) (H-Kittikun et al., 2000). In 2007, FFB production levels of almost 6.4 million tons per year may theoretically be used to produce 1.15 million tons of CPO per year (OAE, 2009).
There are several issues to be considered upon planning or implementing biofuel production. These are energy balance (Prueksakorn and Gheewala, 2008), petroleum substitution, greenhouse gas emissions (Dale, 2007), land use efficiency (Dale, 2007; Nonhebel, 2005), and water use (Gerbens-Leenes et al., 2009). The net energy is a primary factor used to evaluate whether there is a loss or gain of energy of the biofuel production. This is achieved by comparing all input energy required (or consumed) within the system boundary throughout the life cycle of the biodiesel with the output energy of biodiesel per functional unit. Consequently, net energy could be used as one of the relevant factors to indicate the long-term sustainability of biodiesel.
The energy consumption for biodiesel production was related to the energy required both directly (petroleum products, electricity) and indirectly (used for producing materials and for equipment) in the fuel life cycle. The energy analysis performed by Hovelius and Hansson (1999) on rapeseed oil biodiesel indicated that the energy consumption mainly came from the fertilizers and diesel used in cultivation. Janulis (2004), while studying the energy usage of rapeseed methyl ester (RME) and rapeseed ethyl ester (REE) production, which consisted of agriculture, oil pressing, and transesterification, showed that energy consumption for production was 31,406.9 MJ per ton for RME and 30,426.5 MJ per ton for REE. Tan et al. (2004) reported a consumption of heat energy and electricity energy of 2.08 and 3.25 MJ, respectively, for the production of 1 kg of coconut biodiesel. Prueksakorn and Gheewala (2008) studied the life cycle energy balance of Jatropha biodiesel production; in the case where all by-products are used, net energy will be only slightly gained or even at a loss. On the other hand, if all by-products would be used, the net energy will be positive for all scenarios.
As it has been shown that the energy balances of biofuel production depend on agricultural patterns and processes, as well as the technology used, this study aimed to (1) evaluate the life cycle energy consumption of PME production in Thailand, (2) estimate the energy potentials of PME, and (3) compare the energy performance differences among several fuels. The analysis covered 4 stages: the oil palm plantation, the crude palm oil and its derivative production, the transportation, and finally the conversion to biodiesel. All energy inputs in each stage were evaluated and compared with the energy output of the biodiesel product.
Section snippets
Goal and scope of research
The goal of this study was to evaluate the life cycle energy balance and potential of palm oil methyl ester (PME) production in Thailand. The scope includes the oil palm plantation and harvesting, CPO and its derivative production, transesterification, and all transportation activities within the system boundary. Fig. 1 shows all stages and the system boundary of the PME life cycle.
The functional unit (FU) of this study was defined as 1 kg of PME produced from palm oil and its derivative as
Net energy analysis
The results of the life cycle energy analysis for the production of 1 kg PME are shown in Fig. 3. It is clear that the transesterification, or conversion, stage has the highest energy consumption, followed by the oil palm plantation and harvesting, and the transportation stage. The CPO extraction stage is lowest because of the use of biomass residues (palm fiber) as fuel in this stage for power and steam production. FFB processing to CPO and co-products consumes 7.2 MJ/kg CPO, more than 95% of
Conclusion
The present study shows the results of the life cycle energy analysis performed for palm oil methyl ester (PME) production. All life cycle elements of PME, including oil palm plantation and harvesting, CPO extraction, transesterification, and transportation, are evaluated based on 1 kg of PME. The energy analysis results of the present situation show the NEG and NER of PME biodiesel to be 24.03 MJ/FU and 2.48, respectively. It is shown that major energy consumption comes from the
Acknowledgements
This research is supported by the National Metal and Materials Technology Center under National Science and Technology Development Agency, Ministry of Science and Technology (Thailand). The authors would like to thank all contributors for the data used in this study.
References (33)
Importance of biodiesel as transportation fuel
Energy Policy
(2007)- et al.
The water footprint of energy from biomass: a quantitative assessment and consequences of an increasing share of bio-energy in energy supply
Ecological Economics
(2009) Reduction of energy consumption in biodiesel fuel life cycle
Renewable Energy
(2004)Renewable energy and food supply: will there be enough land?
Renewable and Sustainable Energy Reviews
(2005)- et al.
Energy and energy analysis of rapeseed oil methyl ester (RME) production under Swedish conditions
Biomass and Bioenergy
(1999) - et al.
Net energy, CO2 emission, and life-cycle cost assessment of cassava-based ethanol as an alternative automotive fuel in China
Applied Energy
(2004) - et al.
Environmental aspects of ethanol derived from no-tilled corn grain: nonrenewable energy consumption and greenhouse gas emissions
Biomass and Bioenergy
(2005) - et al.
Full chain energy analysis of biodiesel production from palm oil in Thailand
Applied Energy
(2009) - et al.
Carbon balance implications of coconut biodiesel utilization in the Philippine automotive transport sector.
Biomass and Bioenergy
(2004) - et al.
A review of assessments conducted on bio-ethanol as a transportation fuel from a net energy, greenhouse gas, and environmental life cycle perspective
Journal of Cleaner Production
(2007)
Life cycle assessment of palm biodiesel: revealing facts and benefits for sustainability
Applied Energy
Renewable energy from palm oil—innovation on effective utilization of waste
Journal of Cleaner Production
The energy balance in the palm oil-derived methyl ester (PME) life cycle for the cases in Brazil and Colombia
Renewable Energy
Thinking clearly about biofuels: ending the irrelevant ‘net energy’ debate and developing better performance metrics for alternative fuels
Biofuels, Bioproducts & Biorefining
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