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| Fig. 1: Oil Palm Plantation in Malaysia. (Source: Wikimedia Commons) |
While palm-oil is a valuable commodity that is used as cooking oil, food additives, and cosmetic products, it is also used in a variety of forms as a renewable energy source. [1,2] Its main use is for the production of palm-oil based biodiesel. Palm oil biodiesel is nontoxic and biodegradable in addition to emitting far fewer carbon emissions than traditional petro-diesel. In addition to palm oil biodiesel, oil palm tree biomass can be turned into methane, bio-plastics, organic acids, bio-compost, active carbon, plywood, and animal feedstock. [1] Fig. 1 depicts an oil palm plantation in Malaysia.
With the increasing pressure of climate change, there is an increasing demand for biofuels that are less carbon heavy than traditional diesel. The vegetable oils used to make various forms of biodiesel come from the seeds of oil-bearing crops, in this case, oil palm fruit. Palm oil has the highest yields of oil per hectare of plantation, making it the cheapest vegetable oil use in biodiesel today. It is also a perennial crop with a lifespan of around 25 years so it can produce high yields of oil for a long duration of time. These characteristics make it an attractive economic opportunity for a developing country with a growing economy such as Malaysia. [2] It has been a significant contributor to the development of the Malaysian economy and has brought many out of poverty. The industry, in Malaysia alone, provides ~860,000 indirect and direct employment opportunities, serving a large need in the area. Malaysian palm oil exports have been estimated to feed 1.3 billion people in around 150 different countries. [1] While there are many environmental effects of the oil palm industry, in particular deforestation of tropical forests, there are also oxygenation benefits that the crop cultivation brings. Large oil palm plantations can act as large carbon sequestering sinks which is another economic advantage for the people of Malaysia. This can be converted to carbon credit which is a commodity that can be traded for economic value. While the forests that originally remained there were also a carbon sink, and perhaps a better one, they did not bring economic value to Malaysians for this service. [1]
While there are many overall benefits to biodiesel there are a few disadvantages that make the switch from petrodiesel to biodiesel economically challenging. Bio-diesel is chemically different from petro-diesel and produced from a different substance, mostly vegetable oil triglycerides. [2] Traditional diesel from petroleum based compounds contain long hydrocarbon chains but have no oxygen compound. [3] It has a much lower sulfur content, which is great because the burning of high sulfur petro diesel contributes to atmospheric pollution and specifically the development of acid rain. It also has a much lower pouring point than petro-diesel, meaning it can be produced for feasible use in colder climates. Additionally, not only does palm oil biodiesel produce fewer carbon emissions but also leaves less carbon build up in diesel engines. On the contrary there are physical characteristics that make it difficult: it has a higher flashpoint, a higher viscosity and most importantly a lower gross heat of combustion. [2] While these characteristics pose an issue for running diesel engines fully on biodiesel, these characteristics are almost negligent when implemented in small mixing percentages such as 5-10%. This has been done in the U.S. using ethanol from corn to produce E85, which contains 15% ethanol relative to 85% petrodiesel. [3] In Malaysia, government policy is trying to implement B95, which contains 5% palm oil. [1,2]
The implementation of small percentages of palm oil biodiesel into our traditional petrodisel would result in fewer carbon emissions when combusted in a diesel engine, however, its overall environmental impact may outweigh its potential benefits. Deforestation for the planting of oil palm is a huge problem for the industry. It is a massive loss of biodiversity as tropical forests are home to some of the most significant biodiversity on our planet. This deforestation has also caused mass amounts of soil erosion and ground water pollution. [2] It also acts as a significant loss of carbon sequestration. While proponents of the oil palm industry suggest that plantations do operate as a carbon sink in a similar fashion to the forests, there is significant debate as to whether they sequester as much carbon as the tropical forests. The oil palms take about 12 years to become fully grown, in which time the forests could have been continuously sequestering carbon. To that point, does the small percent carbon reduction in combustion outweigh the removal of large carbon sequestering forests? Finally, the development of biodiesel is renewable but not clean: carbon and other pollutants are emitted in the processing and refining steps of oil palm biodiesel production. [2] These are all issues that need to be addressed effectively before more investment is made into palm oil biodiesel that provide significant barriers to the palm oil industry and Malaysian economic development.
© Eva Wallack. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] S. Sumathi, S. P. Chai, and A. R. Mohamed, "Utilization of Oil Palm as a Source of Renewable Energy in Malaysia," Renew. Sust. Energy Rev. 12, 2404 (2008).
[2] R. Pool, The Nexus of Biofuels, Climate Change, and Human Health: Workshop Summary (National Academies Press, 2014).
[3] R. El-Araby et al., "Study on the Characteristics of Palm Oil-Biodiesel-Diesel Fuel Blend," Egypt. J. Pet. 27, 187 (2018).
