Global Fossil Fuel Consumption
During the past few decades, fossil fuel consumption has accelerated dramatically around the world. A significant driver of global fossil fuel consumption is directly linked to transportation systems. As the global automobile population has continued to increase over the past century, fossil fuel consumption has grown precipitously. Population growth and rising household incomes in developing regions like Southeast Asia and Africa are projected to contribute to an increasing number of new automobiles on the road. According to economic reports, sustained growth in the global population of vehicles is expected to rise from one billion automobiles in 2016 to over two billion automobiles by 2040 (Sioshansi & Webb, 2019). To accommodate more cars and trucks on the road, while also being conscious of global carbon emissions, researchers have been evaluating the viability of biodiesel as an alternative fuel.
Alternative Fuels Research
Research related to alternative fuel development has increased significantly since the early 2000s. Dramatic fluctuations in the price of gasoline and diesel and concerns related tp climate change have led policy leaders around the world to fund alternative fuels research. Environmentalists hope that the transition away from conventional internal combustion engine vehicles will continue to intensify in the coming decades. Research has shown that electric vehicles are already starting to have an impact on global oil consumption. Similarly, the notion of transportation systems fueled by natural gas has also attracted the interest of automakers and policy initiatives from the U.S. Department of Energy. While electric vehicles and natural gas transportation systems have been in the media headlines in recent years, biodiesel is often an overlooked option as a fuel for conventional internal combustion engine vehicles.
Biodiesel is known as an alternative fuel derived from biomass and biological sources like edible and nonedible oils, waste cooking oils, and animal fats. This diesel-equivalent fuel can be developed by processing biodegradable and non-toxic substances into a variety of alternative fuels that can be used in transportation systems and for energy generation. Moreover, some scientists and environmentalists believe that investments made in biodiesel technology could be a crucial part of efforts to reduce global greenhouse gas emissions. One of the best aspects of biodiesel is that it can be used as fuel in traditional diesel engines without the needs to make engine modifications. Since the transportation sector accounts for over 50 percent of the global oil demand and produces about 25 percent of global carbon emissions, replacing conventional petroleum-based fuels with biodiesel may reduce emissions and lower the demand for fossil fuels (Ibeto and Ugwu, 2018).
The world’s developing countries like China and India make up about 10 percent of the global automobile population and a little more than 20 percent of the world’s transportation-related energy consumption (Ibeto and Ugwu, 2018). With the rapid rates automobile adoption in these countries, global greenhouse gas emissions are destined to continue increasing if alternative fuel technologies are not adopted. As a result of the expected increase in automobile ownership in the developing world, Morgan Stanley economic researchers have forecasted that the global demand for petroleum-based fuels will triple by the mid-2030s (Domm, 2018). Could the development of biodiesel technology make these researchers rethink their calculations?
Global Biodiesel Supplies
The world’s supply of biodiesel grew from 3.9 billion liters in 2005 to just over 18.1 billion liters in 2010 (Rouhany and Montgomery, 2019). By 2025, economic analysis predicts that 41.4 billion liters could be produced globally, which would represent a 25 percent increase over 2016 levels (Rouhany and Montgomery, 2019). While traditional diesel has become the subject of increasing scrutiny because of the clean diesel emissions scandal, biodiesel has the ability to substantially reduce greenhouse gas emissions. When compared to traditional gasoline and diesel using a lifecycle emissions assessment, research has shown that biodiesel can reduce greenhouse gas emissions by 20 to 80 percent (Pacini et al, 2014). As crude oil continues to become more challenging and energy intensive to extract, the life cycle efficiencies of biodiesel may continue to climb.
While studies have shown the biodiesel is a much more environmentally friendly option when compared to traditional diesel and gasoline, the process for making biodiesel can be lengthy and expensive. However, biodiesel prices have been on a downward decline due to pressure from declining petroleum prices. At an international level, prices for biodiesel are expected to increase over the next 10 years, as the expected recovery in crude oil prices will drive up the price of biodiesel feedstock (Rouhany and Montgomery, 2019).
The process for making biodiesel has interestingly been compared to the process of making homemade soap. After starting with a base oil substance like animal fats or cooking oil, potassium hydroxide or sodium hydroxide is added and mixed with methanol. After these substances are mixed together and processed further, a chemical reaction takes place that produces biodiesel and glycerin, which is a common base substance used to make a variety of soaps. While the process may seem somewhat straightforward, many individuals who try to make their own biodiesel end up making mistakes due to the highly caustic nature of mixing methanol, potassium hydroxide, sodium hydroxide, and cooking oils together. Because of the corrosive nature of these substances, a stainless-steel mixing drum must be used to avoid any unwanted chemical reactions that could damage a vehicle’s engine.
In addition to not using a stainless-steel mixing drum, another common mistake that is made with small-scale biodiesel operations is related to the mixing method itself. If potassium hydroxide and methanol are mixed together too rapidly, the reactants could combine explosively. Therefore, small-scale biodiesel operations are urged to combine substances using a slow trickle over constant low heat for 12 to 14 hours. After the liquids have mixed together completely, another 24 hours is needed to allow for the chemical reaction to fully subside. Following this step, the glycerin byproduct should be fully separated from the biodiesel. After separating the remaining glycerin from the biodiesel, the fuel is ready to be filtered and stored for use as an alternative fuel. As a whole, making biodiesel is a laborious and time-intensive process that may not service to be cost-effective solutions for small-scale operations looking to save money on fuel.
While small-scales operations may take up to 48 hours to make a single drum of biodiesel, large-scale producers have started to develop technology that can produce biodiesel in a matter of minutes (Datta and Mandal, 2016). From a chemical perspective, scientists refer to biodiesel as a monoalkyl ester of long chain fatty acids. Biodiesel produces much less carbon dioxide than petroleum-based fuels, has a very low level of particulate matter, and contains no sulfur. Biodiesel also contains more free oxygen than regular diesel, which means that a more complete level of combustion is able to take place within a vehicle’s engine. Reduced levels of combustion, as is typical with older diesel vehicles, produces significantly more smog-causing particulate matter.
Microalgae as Fuel
In addition to using plant-based oils and animal fats to produce biodiesel, microalgae are rapidly becoming a new and promising source of biodiesel. Microalgae are very small, photosynthetic microorganisms that can reproduce quickly and be grown in many climatic conditions throughout the year. While petroleum-based diesel fuel produces a number of harmful gases and other toxins when burned, the pollutants that are released from fossil fuels can serve as beneficial nutrients for microalgae (Srivastava and Gaurav, 2019). Therefore, producing microalgae for fuel would not only reduce vehicle tailpipe emissions, but may help reduce levels of carbon dioxide in the atmosphere. If large-scale microalgae farms are developed, these microorganisms may be able to mitigate some of the harmful emissions that are produced by using fossil fuels in other economic sectors.
The overall environmental benefit of biodiesel production is still the subject of continued debate. While biodiesel is fully biodegradable and provides air quality benefits in the form of reduced carbon emissions, volatile organic compounds, and sulfur oxides, a great deal of criticism is focused on the negative impacts from using agriculturally based biomass feedstock as a source for biodiesel. If fossil fuels were to be reduced dramatically from the global transportation system and replaced with biodiesel, the massive growth in industrialized biomass feedstock farms would adversely impact forests and grasslands, increase food and animal feed prices, initiate a loss of biodiversity from large mono-cropped fields, and create even more water resource management challenges (Rouhany and Montgomery, 2019). Small-scale biodiesel operations that make use of biomass or other biological materials that are already labeled as waste materials would achieve a net environmental benefit. However, the prospect of industrialized biodiesel operations creates numerous challenges related to sustainability.
A Globally Traded Fuel
Even with recent negative media coverage related to petroleum-based diesel fuel scandals, the global share of diesel vehicles has been increasing in comparison to the global share of gasoline vehicles. The production of biodiesel has also followed this upward trend in recent years. The implementation of numerous pro-biodiesel policies in the European Union and the U.S. has been a driving force for the development of more commercial biodiesel operations. While biodiesel has historically not been a fuel that has been traded on the global market, soy-based biodiesel from Argentina and palm-based biodiesel from Indonesia have started to be exported globally.
Between 2005 and 2015, the global production of biodiesel increased by more than 20 percent annually, which ended up initiating a sevenfold expansion in a single decade (Rouhany and Montgomery, 2019). Even with this substantial increase, biodiesel still only accounts for about four percent of the world’s transportation fuels (Rouhany and Montgomery, 2019). According to the United Nations’ Food and Agriculture Organization and the Organization for Economic Cooperation and Development, biodiesel production is only expected to increase gradually over the next decade. Instead, automakers and global policy leaders are shifting their attention to the production of electric vehicles.
The global biodiesel market has grown impressively over the past decade. However, concerns related to environmental sustainability and the viability of large-scale production facilities has hindered progress within the past couple of years. Moreover, there are very few studies available that indicate how biodiesel production can be profitable without government subsidies and other production incentives. Biodiesel advocates often point to fossil fuel subsidies as evidence that government support could help the biodiesel industry take flight. Lobbyists continue to advocate for a reduction in fossil fuel subsidies in place of subsidies for biodiesel production. Renewable energy directives and alternative fuel mandates could also serve to benefit the future of global biodiesel production. While the notion of reduced greenhouse gas emissions makes biodiesel appear to be an attractive fuel, there are still numerous challenges that must be overcome for biodiesel to become a viable fuel on the global marketplace.
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Domm, P. (2018). “Electric vehicles: The little industry that could take a bite out of oil demand.” CNBC.
Ibeto, C., & Ugwu, C. (2018). “Exhaust Emissions from Engines Fueled with Petrol, Diesel and their Blends with Biodiesel Produced from Waste Cooking Oil.” Department of Pure and Industrial Chemistry, University of Nigeria: Polish Journal of Environmental Studies. Volume 28, Number 5, Pages 3197-3206.
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Srivastava, N., and Gaurav, K. (2019). “Biodiesel and its Production: Renewable Source of Energy.” Journal of Biochemistry Technology: Volume 10, Number 3, Pages 1-10.