Biofuels are seen as greener than fossil fuels but could cause more harm than good
Keith Carpenter, Straits Times 15 Mar 08;
AS EUROPEAN countries strive to meet their targets for the substitution of fossil fuels by biofuels, and as the United States forges ahead with producing ethanol from corn, the world is questioning if these are bold moves that will save the planet - or environmental madness.
Are biofuels good? Will they lead to a reduction in greenhouse gas emissions? Or are they bad, leading to rising food prices, the destruction of rainforests, the depletion of wildlife diversity and water shortages? Will producing them consume more energy than the biofuels themselves contain, generating more greenhouse gases than burning fossil fuels would?
The answer is: It depends.
Some biofuels are good and some are not so good.
It depends on what the fuel is, how and where the biomass was produced, what else the land could have been used for, how the fuel was processed and how it is used.
There are many different biofuels, but the two that are widely available commercially are ethanol, usually blended in petrol, and biodiesel.
Ethanol
ETHANOL is produced by fermentation of starch and sugars, just as it has been for centuries in beer, wine and spirits. The current major sources are corn, sugar cane, sugar beet and cassava. Put simply, producing ethanol from sugar cane in the tropics, particularly in Brazil, and using it to replace petrol is good for the environment and makes economic sense, even with today's level of technology.
Producing it from corn is much less beneficial, although still better than burning fossil fuel. It has resulted in rising corn prices.
It is projected that 30 per cent of the corn produced in the US will be converted into ethanol this year.
Coupled with a global reduction in stockpiles and a poor harvest in the Ukraine, this has led to sharply rising prices.
So why is there such a strong drive for ethanol as a fuel in the US? The answer really is energy security.
The Energy Independence and Security Act of 2005 set the following target: for biofuels to provide 30 per cent of America's energy needs.
The environment is not mentioned in the title of the Act. Its purpose is to reduce dependence on imported crude oil.
Looking forward, the situation is more optimistic.
There is large investment in alternative technology to produce ethanol from cellulosic waste, such as waste timber. A range of alternative crops is being studied for the production of ethanol and other alcohols as fuel.
These have great potential to reduce dependence on crude oil and, at the same time, lower greenhouse gas emissions.
The situation in Brazil and the tropics is quite contentious. Destroying virgin rainforest in order to plant crops is clearly bad for the environment, no matter what the crops are used for.
However, there does not have to be any link between rainforest destruction and the cultivation of sugar cane or cassava for fuel.
In Brazil, for example, according to the Sugar Cane Industry Association, only 1 per cent of the available arable land is used for ethanol production. It would be possible to double production without any impact on farming practices or rainforests.
Cassava is a relatively hardy crop that can be grown on marginal land. Although it requires more processing than sugar cane, it could provide a source of ethanol in some countries, with no impact on rainforests.
Biodiesel and natural oils
THE current generation of biodiesel is a chemically modified natural oil known as Fatty Acid Methyl Ester (Fame). It can be produced from any natural oil and even waste cooking oil. Current major sources are rapeseed or canola oil and palm oil. Others are soya bean, castor oil, sunflower seeds and, in the Philippines, even coconut oil.
Converting the palm oil produced on an existing plantation into Fame biodiesel makes very good environmental sense. Making the conversion from other sources is also generally good for the environment, although it depends a little on how the crop was grown.
However, palm oil is a valuable commodity. It is used in many consumer products and as cooking oil. It is in high demand and as the supply is limited by the current plantation capacity, its price is rising.
Currently, it is a better commercial proposition to sell refined palm oil than to convert it into biodiesel.
However, the conversion of palm oil into biodiesel keeps upward pressure on the price. A high price may drive people to create palm plantations in what was previously a forest. We do not know whether this will happen and if it can be prevented, given that the amount of palm oil used for biodiesel is presently very small.
Biodiesel has an optimistic future, as Fame can be produced from waste oils.
New processes, such as the Neste Oil process, can convert any oil or fat into high-quality diesel. Finnish oil refiner Neste Oil is building the world's biggest biodiesel plant in Singapore at a cost of $1.18 billion.
Potential new crops may be able to replace palm and rapeseed. Two new sources are Jatropha curcas and marine algae. Both are under development around the world and are being studied here.
Jatropha is a hardy crop that can be cultivated on marginal land. It is not farmed commercially on a large scale yet, but plantations are being developed in China, Indonesia, India and Africa.
It will take some time to develop reliable farming practices, but it holds promise as a source of oil independent of rainforests and of arable land for food production.
Marine algae was studied for many years in the US but this was never taken to a commercial scale for fuels, although there are a few examples of its commercial use in speciality chemicals and as food supplements.
They potentially will not compete with food crops for land, but would require large marine ponds.
Although large-scale cultivation, harvesting and processing do not appear commercially viable at present, it is hoped that with modern biological techniques and modern processing, they could become a feasible source of biomass for fuels and chemicals.
The Singapore perspective
SINGAPORE is very well placed to take advantage of the developments in the next generation of biofuels. There are several active research and development organisations and commercial biodiesel plants, including the new-technology Neste Oil process.
Jatropha is being studied by the Temasek Life Sciences Laboratory and the Institute of Environmental Sciences and Engineering (IESE). The Tropical Marine Sciences Institute is studying marine algae, as is the Institute of Chemical and Engineering Sciences (ICES).
The ICES is also studying cellulosic ethanol, biomass gasification and the production of methanol via fermentation. The ICES and the IESE have both developed enzymatic Fame biodiesel processes, while ICES, the National University of Singapore (NUS) and the Nanyang Technological University (NTU) are investigating different aspects of biogas production from waste.
A promising technology is the gasification of biomass to synthesis gas, or syngas, and then making synthetic fuel from the syngas. The ICES, NTU and NUS are researching different aspects of this technology.
Many of these R&D labs are also investigating the conversion of biomass to chemicals. Although not covered in this article, this will be an equally important use for our natural resources in future.
Most biofuels have some positive impact when used to replace fossil fuels, provided that they do not involve the destruction of virgin rainforests.
There are difficulties, as there always are with new technology.
But biofuels are a potentially valuable weapon against climate change if developed within a proper framework of environmental assessment and a true understanding of the total impact of their production and use on the environment.
The writer is the executive director of the Institute of Chemical and Engineering Sciences (ICES), an institute of the Agency for Science, Technology and Research. This article represents his personal view. Dr P.K. Wong of ICES provided much of the information for this article.
