By Arvin Charles
With all the growing concerns about global warming and the rapid depletion of fossil fuel reservoirs, one cannot help but wonder if we will ever develop the level of technology envisioned in the classic ‘Back to the Future’ movies, particularly the Mr. Fusion Home Energy Reactor. All Doc. Brown has to do in these movies to power his time-travelling car is to feed it with rotting banana skins and stale beer he scavenged from trash bins nearby. Sadly, the closest we could do to power vehicles from biological waste which is commercially viable and currently feasible would be biofuels, namely biodiesel. Synthesized from vegetable oils or used cooking oils and having a cleaner and lower emissions compared to petrodiesels, biodiesel may sound like the “Hail Mary” we have been waiting for that could solve all our energy problems. Nonetheless, the production of biodiesel brings about a plethora of other challenges that have to be addressed before we could even think about a global transition from petroleum fuels to biofuels.
Biodiesel is produced via the transesterification process from the reaction between used cooking oil (UCO) or vegetable oil with methanol leaving fatty acid methyl esters (biodiesel) and a side product of glycerine. The manufacture of biodiesel seems appealing due to the raw materials needed which can be replenished and is also easily available. The only tricky bit in this process would lie in the control of the catalyst (sodium hydroxide) which might cause saponification (the formation of soaps) if too much is added. There is also the task of separating the biodiesel from the glycerine produced in the reaction and also the filtration in the case where UCO is used as the reactant.
The performance and efficiency of the biodiesel produced mainly depends on the types and composition of the fatty acid methyl esters (FAME) in the product which will influence properties such as the density, viscosity, cetane number and oxidative stability. Studies have shown that the combustion of biodiesel produces approximately the same energy content as regular petrodiesels with lower carbon emissions. Biodiesel also has the upper hand when it comes to the lubricity of the fuels which is beneficial for the lifespan of internal combustion engines. Furthermore, biodiesel is also highly preferable as it can be used readily in normal diesel engines compared to other green alternatives like hydrogen powered and electrical hybrid vehicles which require the purchase of a new vehicle. The only drawback when it comes to the performance of the biodiesel would be its high freezing point which causes the biodiesel to agglomerate and causes clogging in engines especially during winter in certain countries. However, ongoing research is being done to lower the freezing point by using chemical depressants making biodiesel with the same quality or perhaps even better compared to crude oil diesel.
Crops for food vs crops for fuel.
With that being said, although most of the challenges regarding the performance of biodiesel as an alternative fuel source is somewhat solved, there are many barriers which prevent the commercial production of biodiesel. The production of biodiesel at a grand scale would indeed increase employment and rural development for many developing countries around the world. However, following these advancements, a trail of ethical issues would also surface, mainly the issue of growing vegetable crops as a raw material for fuel production rather than feed stock. The high demand of crops such as soybean, maize and rapeseed for biodiesel manufacturing would cause many farmers especially in poor
countries to give in to the prospect of surrendering their lands to biodiesel companies to make ends meet rather than cultivating crops to sustain the food market. As a result, there will be a scarcity of food in these countries, unable to meet the demands of an ever growing population. A good example would be the scarcity of corn in Mexico during the 2007-2008 food price rise, believed to have sparked from the high demand of corn to produce clean biofuels in the United States. The sharp rise in the price of the tortilla bread (which was the staple food for the poorest people in Mexico) to almost 400% created a great fear of malnourishment among many Mexicans leading to a massive tortilla protest. Hence, the ethical issue of food security versus growing crops for fuel is one of the major issues that hinder the prospect of biodiesel as an alternative to replace fossil fuels globally.
Green technology or another source of climate change in disguise?
Apart from that, many also believe that biodiesel may even create a bigger environmental impact than fossil fuels. Although the fact that biodiesel produces far less carbon emissions compared to petrodiesel still stands, the push for biodiesel manufacturing may lead to rapid deforestation. This is mainly due to the constant need for fertile land to sustain the growth of crop plantations as a steady feed for biodiesel manufacturing plants. On top of its contribution to greenhouse effects and global warming, deforestation due to biodiesel generation also brings about the destruction of habitats which eventually leads to the extinction of various wildlife species. Brazil for instance, being one of the world’s biggest manufacturer and consumer of biodiesel, achieved total energy independence even though the country does not have any fossil fuel reserves. Hence, due to the economic pressure to produce soybean crop yields to sustain the production of biofuels, agricultural expansions into the Amazon has been increasing. Although laws and legislations such as the Brazilian Forestry Code do exist to protect the Amazon from receding further, there is very little to no enforcement owing to the country’s inefficient judicial system.
In short, biofuels as in the case of biodiesel, does indeed possess the potential to replace fossil fuels as a source of energy. With its mass production comes also the prospect of job opportunities and also development to countries that are blessed with fertile land. However, laws and regulations have to be enforced in order to protect food security and also excessive deforestation that will follow the biodiesel boom.