Palm Oil Biodiesel – A Preferred Biofuel Feedstock
Palm oil together with corn, rapeseed, soybean and sugar cane are viable feedstocks for use as first generation biofuel.
According to the Food and Agriculture Authority (FAO) from a sustainability perspective, biofuels offer both advantages (energy security, GHG reductions, reduced air pollution) and risks (intensive use of resources, monocultures, reduced biodiversity and even higher GHG through land use change). Therefore, to measure biofuel’s sustainability, economic, environment and social sustainability factors must be considered.
In terms of yield productivity, sugar cane and palm oil rank the highest. Sugar cane yields 6,000 litres of biofuel per hectare (l/ha), followed by oil palm and sugar beet (5,000-6,000 l/ha) but palm oil is superior as it has 27% higher energy content (30.53 MJ/l) than ethanol from sugarcane (24MJ/l). Moderately efficient feedstock’s such as corn, cassava and sweet sorghum yield 1,500-4,000 litres of biofuel per hectare( l/ha). Rapeseed, wheat and soya are the least efficient, yielding less than 1,500 l/ha. Interestingly, it is these moderate to low efficient feedstocks that are used in countries with mandated biofuel programmes; in the US biofuels from soya and corn are used while in EU rapeseed is the preferred choice. Although the use of these feedstocks may not be economical, they become viable due to subsidies and mandates set by the governments.
FAO’s search found sweet sorghum as another possible alternative biofuel feedstock. Although it can rival sugar cane in terms of productivity, it requires quick processing after harvesting and poses challenges for transportation and storage given the bulkiness of the crop.
Jatropha was thought to be a plausible biofuel that would put to rest the “food versus biofuel” debate. As the first generation biofuels are also food crops, there was a fear that using them for biofuel would create a shortage in the food supply and drive up food prices. According to FAO jatropha would require intensive crop management to be successful which, in turn, would result in competition for top farm land. In reality, any crop grown as a source for biofuel feedstock will still compete with food crops for land and water resources. In the end, economics will trump agronomy in making the choice.
In countries where cassava is grown widely, it is a staple food crop. In these countries, the potential to develop it into biofuel is impeded by limited processing technologies and underdeveloped marketing channels. It is unlikely that it will become a large scale biofuel source.
With regard to advanced biofuels (including cellulosic ethanol), it has not reached the stage to be viably produced commercially. Dedicated energy crops (e.g. alfalfa, swithgrass, miscanthus), fast-growing short rotation trees (e.g. poplar, willows, eucalyptus) and wood and agricultural residues offer great potential. Currently, economics and high capital investment for new supply chains remain serious obstacles for second generation biofuels. It is also cautioned that the advent of second generation biofuels would create pressure for land to produce such crops and worsen the competition with food crops.
Economic sustainability requires long-term profitability, minimal competition with food production and competitiveness with fossil fuels. As biofuel programmes are supported by subsidies and mandates, these factors mask the true economic assessment. It is, thus, difficult to assess the long run economic viability of biofuel systems. Nevertheless, FAO opines that despite the added certification cost, feedstock for biofuels made from palm oil and sugar cane produced by developing countries are still able to compete in the European market. This is a clear indication of the economic viability of these two prime biofuel feedstocks.
The issues tied up with environment sustainability may be global (e.g. climate change, GHG mitigation, renewable energy, ) and local (e.g. water pollution, soil quality, erosion, air pollution). Life cycle assessment methods are often used to study these aspects but the methodologies are not standardized and cannot adequately quantify indirect land use changes.
Fossil energy balance, which is the ratio between renewable energy output and fossil energy input is a good factor to compare biofuel sources. Topping the list is palm oil biodiesel with a fossil energy balance of 9.0. This means that a litre of palm oil biofuel contains 9 times the amount of energy as was required for its production. Sugar cane has values ranging from 2.0 to 8.0. Other feedstock’s; rapeseed, soya and corn have values which fall within 1 to 4.
A major portion of the high fossil fuel energy input to produce temperate biofuels is that they require large quantities of fertilizers; thus, the fear of endangering environment sustainability, e.g. water pollution, at the local level. In comparison with soya and rapeseed, oil palm requires lower inputs of fertilizers and agrochemicals.
Sugar cane has the lowest water footprint, with an average of 29 m3/GJ. while oil palm (75 m3/GJ), sunflower (72 m3/GJ) and soya (99 m3/GJ) have medium water footprints. Rapeseed has a very high water footprint ( average 131 m3/GJ).
Irrespective of which biofuel feedstock is grown, there is concern that biomass (for conversion into biofuels) production under intensive agriculture can have negative impacts on biodiversity, including habitat loss, expansion of invasive species and contamination from fertilizers and herbicides, especially if they are monoculture systems. According to FAO, cultivation of biofuel production systems will destabilize the original biodiversity composition. For oil palm, there is the concern that if large areas of planting in the future are carried out on peat or tropical forest, the carbon debt will be high. (Note:The solution as practised in Malaysia is to commit a minimum of 50% of the total land area to be out of bounds for agriculture and maintained as permanent forest to sustain the mega-biodiversity status of the country.)
The social dimension of biofuel sustainability relates to the potential for rural development, poverty reduction and inclusive growth. The Social Impact Assessment should be used as a tool to measure social sustainability. The FAO report did not compare the various kinds of biofuels in this aspect. This lies in the difficulty of translating social sustainability standards and criteria into measurable indicators. As such, most present systems of measuring social sustainability only pay attention to social aspects which have negative impacts; such as child labour, minimum wages or calling for adherence to national laws or international conventions.
FAO states that critical factors e.g. health implications, poverty eradication or smallholder inclusiveness are not included. Social sustainability must move away from just focusing on a few negative impacts and include these factors and development goals where local communities share sustainably in the economic benefits derived from biofuels in comparison with other alternatives.
Note: A survey showed that small holder farmers in Malaysia who grew oil palm and sold the fruits, obtained an average income of RM 1,356 in 2006. This income was way above the national poverty line of RM 529 for the country. The survey also showed that quality of life of the settlers (farmers) in Felda improved (Source: Ahmad Tarmizi (2008): Felda: A success story, Global Oils & Fats,5,1,6-11).
The sustainability of biofuel feedstocks must be viewed holistically based on economic, environment and social aspects. Amongst them, there is a need to find better criteria to evaluate social sustainability. A single biofuel which satisfies all the aspects completely does not exist. Based on a synopsis of the FAO report, amongst the first generation biofuels which support present biofuel programmes, palm oil biodiesel is seen to be a highly sustainable feedstock, far superior than corn, rapeseed and soya.