Fueling The Future

Green is the new black when it comes to meeting the world’s energy demands, and biofuels have a major role to play in securing a sustainable future.

AsianScientist (Jul. 19, 2019) – Bloodshot eyes, clammy skin, furtive over-the-shoulder glances and the unsuppressed shudder of withdrawal—these signs, among others, give an addict away. What starts out as an experiment or coping mechanism eventually grows to become an all-consuming habit, hard to sustain, even harder to kick.

But confront the addict about his vice, and you will likely see a reaction resembling the Kübler-Ross model of grief: denial, anger, bargaining, depression and acceptance. Addiction resists attempts to call it out and correct it, yet as a society, we still try to extend a hand to those caught up in its web. Perhaps, the same attitude should apply to our addiction to fossil fuels.

Approximately 80 percent of the world’s energy needs today are met by burning fossil fuels, a tradition that traces back thousands of years, but which really only took hold during the First Industrial Revolution some 200 years ago. Coal—the cheap and abundant black ‘rock’ that burns—became the bedrock of manufacturing and transportation in the 1800s, driving an explosion of economic growth. Then in 1859, American businessman Edwin Drake drilled the first oil well in Texas, US, gaining access to petroleum and natural gas, thereby further entrenching our dependence on the combustible remains of long-dead things.

Like the junkie on the street corner who utters “just one more fix and I’m quitting,” we’ve dug coal mine after coal mine and scoured the deepest depths of the ocean for crude oil, always seeking more ‘black gold.’ The global economy and society has progressed as a result, but the environmental cost of this addiction is quickly catching up with its benefits.

Stem the black tide

In 2018, the United Nations (UN) issued a warning that the world has slightly over a decade left to prevent irreversible damage from climate change. Fossil fuels contribute significantly to this man-made phenomenon because of the greenhouse gases they produce upon combustion. Although voices of denial and anger persist, governments and companies across the globe are beginning to acknowledge the threat of climate change and are seeking cleaner, renewable alternatives to fossil fuels.

“The UN’s Sustainable Development Goals call on UN member states to take concrete actions to generate affordable and clean energy. This is urgently needed if we want to create a sustainable society,” said Dr. Kengo Suzuki, director and general manager of R&D at Japanese biotechnology firm euglena Co., Ltd, which has a business unit that produces biofuels from microalgae—tiny organisms found in ponds and moist soil.

Small as they may be, microalgae hold great promise as a sustainable fuel source. Appearing green in color due to the chlorophyll—a light-capturing pigment—inside them, microalgae carry out photosynthesis as plants do, capturing the sun’s energy and absorbing carbon dioxide to grow. Researchers at euglena Co., Ltd have since found ways to hijack this process to turn microalgae into biofuel factories. The trick is to tweak the conditions under which microalgae are cultivated.

“Some types of microalgae belonging to the genus Euglena can be efficiently grown under conditions of high carbon dioxide. Basically, we introduce carbon dioxide and light into a culture device containing a fixed number of microalgae cells, allowing those cells to photosynthesize and grow,” Suzuki explained.

Thereafter, the cells are recovered and kept in a dark, oxygen deficient state. Tricked into thinking that they need to endure a period of starvation, the cells begin to store wax ester, a feedstock for biodiesel and aviation biofuel. The microalgae are subsequently dried, and the wax ester is extracted using an organic solvent. In this manner, microalgae double up as a carbon sink and biofuel source.

Suzuki tells Asian Scientist Magazine that euglena Co., Ltd completed the construction of its first biodiesel production plant in October 2018. The plant has a production capacity of 125,000 liters per year, and is now running trials for biofuel production using microalgae. If black is the flagship color of pollutive fossil fuels, then green may well be the hue of renewable energy sources that have lower carbon footprints.

Oiling the gears of sustainability

Growing huge vats of microalgae and then wringing oil from them is but one way to obtain fuels from biomass. Vegetable oil and animal fat can also be chemically converted into renewable energy sources. Importantly, with the right techniques, even waste fat from the food and agriculture industries can find a new lease of life as biofuels. This is what Finnish energy giant Neste is doing at its oil refineries, one of which is located in Singapore.

“The chemistry to obtain renewable diesel from a broad range of waste animal fats and vegetable oil-based residues involves passing triglycerides—the main constituent in vegetable and animal fats—through a hydrodeoxygenation process,” said Mr. Kenneth Lim, site director of Neste Singapore.

Put simply, the triglycerides are reacted with hydrogen under heat and pressure in the presence of a platinum catalyst to remove impurities such as sulfur, oxygen and nitrogen. The reaction is exothermic, and the excess heat produced is used to heat up the incoming feed, thus reducing the requirement for external energy. At the end of the reaction, paraffinic hydrocarbons—compounds with a specific proportion of carbon and hydrogen atoms (CnH2n+2)—are produced, which can be further refined into renewable diesel.

“Neste’s renewable diesel is fully compatible with existing engines and distribution systems,” Lim noted.

Although conventional biodiesel can only be blended with fossil diesel up to a maximum of ten percent of the total fuel volume (above which problems with the engines and emissions arise because of impurities and oxidation), Lim highlighted that Neste’s renewable diesel has no blend limit and can even be used as a standalone fuel.

Neste’s Singapore refinery currently produces 1.2 billion tons of renewable diesel and other renewable products annually. It recently announced an additional €1.4 billion investment to double its production capacity as well as upgrade its facilities to produce aviation fuel, which is held to a higher standard of purity and efficiency, said Lim. According to Neste president and chief executive Mr. Peter Vanacker, this is the single biggest investment in Neste’s history, a testament to the company’s commitment to renewables and sustainability.

Room for improvement

Both euglena Co., Ltd and Neste are continuing to invest in R&D to improve their respective approaches to biofuel production. For instance, Neste is exploring the use of novel catalysts that will allow it to increase the range of feedstock material that can be converted into renewable fuel.

“We are also developing ways to treat higher impurity feedstocks that we can then feed into the catalysis process,” Lim said.

Meanwhile, euglena Co., Ltd’s Suzuki leads research on microalgae strains that produce and store more wax esters.

“A large number of cultured Euglena cells are irradiated with an ion beam, and the genes are randomly changed for each cell,” Suzuki explained.

Among the mutants generated, his team then identifies cells that contain higher oil content and carries out selective breeding to expand microalgae populations that are more efficient at biofuel production.

Scientists can also use metabolic engineering tools to reduce the element of chance in creating desirable mutant strains, as well as expand the repertoire of microorganisms that can ‘manufacture’ biofuels.

“Metabolic engineering is very powerful, and if performed properly, can result in the direct production of biofuels by fermentation rather than involving complicated chemical processes,” said Professor Lee Sang Yup at the Korea Advanced Institute of Science and Technology, South Korea.

By understanding and optimizing not only the common pathways closely related to biofuel formation, but the entire metabolic network of specific microorganisms like yeast, Lee’s research group has successfully developed many different microbial strains capable of producing gasoline and butanol from biomass.

“With a good engineered strain, lower direct fixed capital costs and lower energy will be required to produce biofuels at scale,” Lee emphasized.

Raise the green banner

Nonetheless, both Lee and Lim acknowledge that biofuels are currently more expensive to produce than fossil fuels, which means that there will inevitably be some inertia to its widespread use. Overcoming this inertia will take political will, something still relatively lacking in Asia.

“The demand for renewable fuels is currently driven by governments with strong sustainability agendas, for example, the Renewable Energy Directive II (RED II) by the European Union and the Low-Carbon Fuel Standard (LCFS) by the US. These countries are now setting the example for the rest of the world,” said Lim, adding that “it will be a significant step forward if Asia or ASEAN member states can come together and agree to comply with RED II.”

Trade associations also have a role to play in encouraging the uptake of biofuels, and on this front, the International Air Transport Association (IATA) is making significant inroads. Representing 292 airlines, of which 45 are from the Asia-Pacific region, IATA has set an ambitious target of achieving carbon-neutral growth of the air transport industry by 2020, and the airlines are responding.

Japan’s largest airline ANA, for one, will be using euglena Co., Ltd’s microalgae-derived biofuel in its operations in the near future, while the fleet of Germany’s largest airline Lufthansa already runs on renewable aviation fuel from Neste.

Certainly, biofuels are not the panacea to all our problems, and there is still a long way to go before the world kicks its addiction to fossil fuels, but small incremental steps like these are important if we are to leave our planet a better place for generations to come. By making sustainability a key priority of science, industry and policy, we may still be able to avoid the hot, sooty future that our old habits have put us on the trajectory towards.

This article was first published in the July 2019 print version of Asian Scientist Magazine.

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Copyright: Asian Scientist Magazine.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Jeremy received his PhD from Nanyang Technological University, Singapore, where he studied the role of the tumor microenvironment in cancer progression.

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