Green Skies Ahead

Business, Aviation biofules
Summer 2017
Canada's Biojet Supply Chain Initiative is working to integrate jet fuel derived from renewable sources into airport-fuelling infrastructure used by commercial airliners around the globe.

Jet Fuel

In one of several town-hall meetings held across the country early this year, Prime Minister Justin Trudeau sparked controversy by pointing to the need for Canada to phase out its use of fossil fuels in the decades ahead. While his remarks generated predictable discomfort in places where the petroleum industry is a major part of the local economy, they likewise cheered advocates for the adoption of alternative and renewable energy sources. As laudable as that goal may be, however, some sectors are going to have a very hard time embracing the shift.

For a sense of where one of the greatest challenges will appear, cast your eyes upward. Depending on where you live, there may well be a large commercial airplane in view or perhaps the horizon-to-horizon cloudy contrail of one that has already passed overhead. According to the International Civil Aviation Organization, as you read these words there are more than 11,000 aircraft of various descriptions overhead around the world. Depending on the average seat count for these vessels, that means the aviation industry now sustains in the lower stratosphere an itinerant population of at least 100,000 people — about the size of a small city like Kamloops, BC — and is steadily welcoming more fliers from the ranks of ever-richer developing countries.

For most of those people, the key ingredient keeping them aloft is jet fuel, a straw-coloured cousin of kerosene that is the lifeblood of commercial airliners at every major destination in the world. For all their cramped seating, noisy cabins and humiliating security rituals, this form of transportation represents nothing less than a miracle of international standardization, allowing travellers from almost anywhere to make their way to almost anywhere else at a pace that would have qualified as science fiction a century ago. We complain about the conditions only because we take so much of this elaborate infrastructure for granted but its success is undeniable. 

Unfortunately, this successful mix of sheer speed and passenger volume has set the bar impossibly high for other options, especially ones that might be considered more environmentally friendly. That bar is far lower when it comes to ground-based transportation, where practical electric cars are beginning to make their way onto the road in significant numbers. Electric aircraft remain highly experimental, since we are only just beginning to build power sources light enough to carry more than one or two passengers aloft. As matters stand now — and probably for those decades ahead as envisioned by the prime minister — only jet fuel can provide the brute force required to heft tons of people or cargo across the sky with anything like the efficiency we have come to expect.

Despite this harsh reality, investigators have been examining what incremental gains may be possible. In 2009 the Green Aviation Research and Development Network (GARDN), a federally funded collaboration, assembled teams from across the country to work on dozens of different projects around the theme of reducing modern air transportation’s environmental footprint. One of those projects is Canada’s Biojet Supply Chain Initiative (CBSI), which is looking specifically at how jet fuel derived from renewable sources can be integrated into the existing system that serves airports across the country.

Fred Ghatala

Fred Ghatala

“Our project’s approach is to look to commercially available and proven biojet production technologies, to create a demonstration project that enables hydrant system blending in an airport,” says Fred Ghatala, a partner in the Vancouver-based Waterfall Group, a clean energy consulting firm that is spearheading this work.

Most air travellers will be comforted to know that jet fuel meets strict standards defined by ASTM International, which also has a special designation for jet fuel made from biological materials as opposed to traditional petroleum refining. Ghatala notes no fewer than five major chemical pathways that can be used to turn feedstocks such as plant sugars and starches or oil seed extracts into bio-based jet fuel, or “biojet.” ASTM has already certified two of these approaches: Fischer-Tropsch (FT) and hydrotreated esters and fatty acids (HEFA).

In fact, biojet is already being used to refuel planes in Los Angeles, Calif. and Oslo, Norway, where governments have introduced strong policy incentives for airport authorities to adopt this more expensive alternative. According to Ghatala, the challenge no longer lies with the chemistry of creating biojet but the intricate logistics of getting it into the tightly knit fuel delivery infrastructure at the heart of modern aviation.

Currently biojet is delivered directly to aircraft using bowser trucks, those low-slung tankers that can pass under a jetliner’s wings on the tarmac. Ghatala regards this method as less efficient than simply mixing both fuels in the ground-based tanks that are served by fuel-pumping hydrants. “The way that more biojet is going to get into the transportation fuel system is via the co-mingled or hydrant fuel system,” he says. “Everybody gets a bit of biojet when it’s put in the commingled supply system.”

CBSI will mark a major milestone this summer when the strategy is implemented at Montréal–Pierre Elliott Trudeau International Airport. Air Canada is one of 14 partners in the project. Others, such as the International Air Transport Association, Transport Canada, Boeing and the National Research Council, will be watching closely to see whether this innovation can withstand the minute-to-minute pressures of refuelling aircraft in a working airport.

Warren Mabee, who holds the Canada Research Chair in Renewable Energy Development and Implementation at Queen’s University, will also be watching closely. Mabee has studied the interface where ambitious public policies to support renewable fuels meet the often-gritty demands of technology responsible to create and deliver those fuels to customers. As part of CBSI he has been especially interested in how airlines might be able to cap their greenhouse gas (GHG) emissions to meet the demands of a low-carbon economy without altering the fundamental design of the jet engine as the industry’s workhorse. “Biojet suddenly starts to play this really interesting and important role inside one specific sector,” he says.

The gains from biojet are real, as NASA recently confirmed in studies on a standard commercial jetliner running on a 50-50 blend of conventional and biojet fuel. In addition to reducing the GHG footprint of the fuel itself, the aircraft’s emissions contained 50-70 percent fewer particles such as soot, leading to much thinner contrails and other atmospheric effects.

And while aviation’s overall environmental impact may be modest compared with other sectors, Mabee has his eye on a larger target: long-haul trucking. Here too the energy and power requirements for sustaining this far-flung delivery network will make it unlikely that any alternative technology will topple the venerable diesel engine from its highway throne in the next few decades. Nevertheless, what members of CBSI learn about delivering biojet at busy airports could readily be applied to making biodiesel more available to the trucking industry. “You start to see the potential for delivering the jet fuel into this small, high profile area and then more fuel into an area that doesn’t get as much attention but is a much more significant problem,” he says.

Before that can happen, though, the companies at the forefront of biorefining will have to develop more sustainable business models for themselves. Fossil fuel refiners have been defining this sector over the course of the past 150 years, which has resulted in a well-established hierarchy of companies that attend to everything from extracting raw product in oil fields to creating highly specialized commodities from it. 

Jet Fule

Mabee suggests that initial attempts to introduce biologically based fuel sources into this system were premised on one-size-fits-all enterprises, where giant firms tried to manage every aspect of the process, from collecting feedstocks in farm fields or forests to shipping the finished fuels to traditional gas stations. The result was a top-heavy corporate structure that remained uncompetitive and led these businesses to appeal for government assistance through organs such as the prominent ethanol lobby in the Midwestern United States. “What we’re starting to see in the biorefining sector is a better configuration of the different tasks and process steps that need to happen in order to actually end up with these fuels at the end of the day,” Mabee says. 

Mabee points to a facility in Sarnia, Ont. that was established by the major US firm BioAmber. The company partnered with the Japanese multinational Mitsui & Co. to build a biorefinery that turns sugars into succinic acid, a platform chemical used in a wide range of personal care agents and food additives. The Sarnia operation has been designed around the application of a specific strain of yeast that has been licensed from food giant Cargill, as well as the presence of southern Ontario agricultural producers who are now raising crops to serve this market. These supply lines are being further strengthened by a new player, Comet Biorefining, which is setting up its own Sarnia facility to turn biomass into high quality dextrose sugar ready for conversion into succinic acid.

This diverse collection of biorefining interests should thrive, Mabee argues, because they are not trying to jump-start a new sector based on a large-scale petroleum refinery model that took decades to evolve.  “This small approach means the individual companies are each taking on a small piece of risk. They have multiple customers for the product that they might make, so they’re not reliant on one blender or one user downstream.”

Mabee says that biojet refining must leap these same hurdles. Any firm that dedicates itself exclusively to this product will be taking on a great deal of technological responsibility and risk for a single market. If various steps in this undertaking can be shared, on the other hand, each participant could pursue other interests.

Mabee also recommends picking a single fuel strategy and sticking with it. “The enemy of innovation sometimes is diversity. There might be six or seven different types of biojet or bioaviation fuels that we could make but if we try to pursue them all we won’t get anywhere.” For just this reason, HEFA has emerged as the preferred conversion technique that CBSI is backing. It has already been approved by ASTM and is commercially available, in contrast to Fischer-Tropsch, which has some significant technical advantages but remains largely experimental in nature. Similarly, CBSI has pointed to HEFA-compatible oil seed crops that are already widely grown in Canada, such as soy or canola. 

Joann Whalen

Joann Whalen 

According to Joann Whalen, a soil ecology specialist with McGill University, non-edible oilseeds can be integrated into existing farming practices in a way that will actually improve the overall output of the land. The leading candidate for this role is a weedy flowering plant called Camelina sativa, which grows on marginal land with little fertilizer. “Camelina is really well suited to grow on lands where wheat is the agricultural crop,” Whalen says, describing how it can be rotated with wheat from year to year, so that the soil does not build up weeds, insect pests and potential disease.

Whalen has spent much of the last decade examining biofuel issues and she has been pleased to see the CBSI take advantage of existing resources to get biojet into the marketplace as quickly as possible. Researchers can then begin to assess the problems that can only be encountered when the production and delivery system is up and running. 

Above all, Whalen says, it will be crucial to sort out these matters for potential users to embrace the concept of biojet or biofuels of any sort. That makes the final hurdle an administrative one, which is determining how to calculate the carbon offset offered by these products and the credit that will go to anyone who employs them. “Are we counting the molecules of carbon that came from a biofuel versus a fossil fuel accurately? How many of those molecules were used to fuel a particular aircraft and how much carbon credit can the airline claim from using biojet? The best way to figure out what’s going to happen is to undertake the test case and see how the whole system responds, from the physical to the economic components.”