Fossil fuels have dominated the global energy market for centuries, and so most people find it surprising to learn that the first ever diesel engine (1892) was run entirely on peanut oil. German engineer Sir Rudolf Diesel who built the engine was almost prophetic when he said the use of vegetable oils for engine fuels “may seem insignificant today, but such oils may become in course of time as important as petroleum and the coal tar products of the present time.”
Because petroleum fuels were easily available (and at low costs) in the early and mid-nineteenth century, few people were interested in alternatives. But this is no longer the case today: with climate change slowly but surely upending our ecological balance, countries are now urgently exploring cleaner fuel alternatives. And biofuels have, in recent years, been proposed as a promising option. But it is one thing to develop an economically viable biofuel, and a whole other to ensure it does not compete with food crops (the longstanding food vs fuel debate) to create a global food crisis.
In this blog, we examine the commercially available biofuels today and new research on potential options for the future.
What are biofuels and how can they help?
Biofuels are produced either directly or indirectly from biomass. They are broadly classified into three categories: Solid biofuels (fuelwood, wood residues, animal waste, vegetal material), liquid biofuels (biogasoline, biodiesel, bio jet kerosene) and biogases (from anaerobic fermentation and thermal processes).
In the last few years, more and more countries are turning to biofuels over conventional fossil fuels because the former is unlikely to deplete as an energy source in the future.
Other advantages include:
- A reduced dependence on imported fossil fuels
- Less air pollution and lower net carbon emissions than fossil fuels
- A catalyst for rural regeneration that will lead to more agricultural jobs
First and next generation biofuels
Today, ethanol and biodiesel are the two most used biofuels around the world, both of which represent the first generation of biofuel technology. First-generation biofuels are produced from crops like sugar cane, maize (corn) and soybeans.
In recent years, governments and private industries have been increasingly investing in developing next-generation biofuels made from wastes, cellulosic biomass, and algae-based resources. They see it as necessary – and even crucial – to move away from first-generation crops for reasons that include efficiency and cost-effectiveness, and due to recent criticisms of first-generation biofuels for competing with food crops (increasing the risk of food insecurity).
The case for more ‘efficient’ biofuels is made even stronger when their emissions are compared with first generation biofuels. The use of traditional biofuels has shown to result in 40-80% less greenhouse gas (GHG) emissions compared to gasoline or diesel, while next-generation biofuels can result in up to 100% fewer GHG emissions on a life-cycle basis!
Next generation biofuels in development
Although most people would concur with the need to switch to biofuel (and to the next generation versions in particular), the ground-reality is a bit more complex. Only last month, Brussels-based not-for-profit Transport & Environment (T&E) revealed that biofuels are adding €17bn a year to Europe’s fuel bill due to the rising cost of feedstock. Biodiesel is now between 70% and 130% more expensive than fossil diesel on the wholesale market. Experts from T&E stress that the EU should end mandates for crop biofuels and commit to truly sustainable technologies instead.
Fortunately, new research in the works promises some options for the near future:
- A team of Agricultural Research Service (ARS) scientists at the National Center for Agricultural Utilization Research in Peoria, Illinois, recently found a more cost-effective technique to produce cellulosic ethanol. Using a microbiology procedure called ‘adaptive laboratory evolution’, they developed a specialized yeast strain called Clavispora NRRL Y-50464, which outperforms the industry standard Saccharomyces cerevisiae. This new strain is ‘tougher’ in that it shows better heat tolerance, faster growth, and an ability to detoxify harmful by-products like furfural while producing ethanol. The strain also makes its own beta-glucosidase, which eliminates the need to add the enzyme externally and lowers production costs.
- The U.S. Department of Energy’s Pacific Northwest National Laboratory with its partners at Oregon State University and LanzaTech have developed a patented process for converting alcohol sourced from renewable or industrial waste gases into jet or diesel fuel. The new PNNL-patented catalyst converts ethanol directly into a versatile chemical called n-butene. Up until now, n-butene was produced from fossil-based feedstocks using energy-intensive cracking of large molecules. The new technology uses renewable or recycled carbon feedstocks instead, which reduces carbon dioxide emissions in the process. The team is already working toward commercialization by integrating the new process into microchannel reactors built using 3D printing technology. 3D printing allows the team to create a pleated honeycomb of mini-reactors that greatly increase the effective surface-area-to-volume ratio available for the reaction.
- Previously, scientists have had to chemically stitch together chains of cyclopropanes to develop fuel, but this may now be naturally possible using bacteria. According to a recently published study, engineered bacteria can brew chains of three-membered rings that are “more energy dense than some rocket fuels.” The biology behind this is intriguing: an antifungal compound called jawsamycin, produced by Streptomyces bacteria, has five spiky cyclopropane rings in its chain. But its bulky end group makes the molecule difficult to functionalize into a fuel. To work around this problem, the team engineered another Streptomyces strain whose enzymes also produce polycyclopropanes – but without jawsamycin’s bulky ending. However, this research is just proof of concept for now, as they work on ways to scale up synthesis.
- Researchers predict that fourth generation (4G) biofuels like biohydrogen will bring fundamental breakthroughs in the field of biofuels. Although the technology for production is still underway, the concept is based on direct conversion of solar energy into fuel by using raw materials that are inexhaustible, inexpensive and widely available. These next generation biofuels are also known as electrofuels, synthetic fuels or power-to-liquid-fuels. They can be produced with zero emissions and without land use implications associated with other biofuels.
Beyond these specific examples, research continues across multiple avenues to develop alternative feedstocks and advanced technologies so that industries can sidestep combustion during biofuel production. World Biofuel Day calls us to reflect on our fuel usage impact on the environment and explore ways to do this more sustainably in the long term.
Do you have new research to share with us about biofuels around the world? Let us know in the comments below!