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  1. 2010.09.23 Biofuels Could Be Cleared For Aircraft Use
2010.09.23 16:10 News
By Graham Warwick | AVIATION WEEK  Published: September 21, 2010
In just five years, the aviation industry’s decades-long reliance on petroleum-based fuels has been turned on its head. The future lies in fuels from sources that range from animal fat to microalgae. But with the technology in hand, the question now is whether biofuel producers can raise the investment needed to launch commercial-scale production.

Approval of biofuels for use in aircraft, expected by mid-2011, is a critical step. A standard for jet fuels using synthesized hydrocarbons has already been crafted and the first annex, covering synthetic paraffinic kerosene (SPK) produced via the Fischer-Tropsch (F-T) process, was approved last year. But a second annex covering bio-SPKsalso called hydrotreated renewable jet fuel (HRJ)is eagerly awaited, as these promise to reduce aviation’s greenhouse-gas emissions (see p. 60).

For an industry that has used one jet fuel for decades, development of the new D7566 specification by standards organization ASTM International has moved surprisingly quickly. But it has not been easy, requiring substantial fuel and engine testing to ensure synthetic kerosenes are truly drop-in replacements for petroleum-based jet fuel.

As expected, the proposal to amend D7566 to include bio-SPKs did not pass a ballot of ASTM members in June. Opponents, mainly the engine manufacturers, argued that more data are needed on different fuels from different manufacturers and more engine testing is required. One reason is that most of the fuel tested came from Honeywell company UOP, which won a Pentagon contract to supply HRJ for qualification testing, says Tim Edwards, who is leading biofuels research at the U.S. Air Force Research Laboratory (AFRL).

After the vote, the Air Force agreed to share fuel to allow additional commercial engine demonstrations. The service is also conducting biofuel tests on military derivatives of commercial engines, which will help with certification. These include flight tests of the F117 derivative of Pratt & Whitney’s PW2000 turbofan on the C-17 airlifter. An aircraft flew in August with all four engines fueled by a 50:50 blend of conventional JP-8 and HRJ from beef tallow.

Data from the additional fuel and engine testing will be presented to ASTM members, and a re-ballot in December is expected to succeed. This should lead to approval early next year of an annex to the D7566 synthetic-fuel standard allowing bio-SPKs to be used in aircraft in blends of up to 50% with conventional jet fuel. This will be a pivotal event, as certification is expected to remove a significant barrier to investment in large-scale facilities to produce HRJ fuels in economic quantities.

“Nothing matters until you get that approval,” says Tom Todaro, chief executive of AltAir Fuels and Sustainable Oils, which produces oil from camelina, a plant that largely does not compete with food crops for land or water. “The problem is the availability of financing, not camelina. We can’t get the money until the fuel is certified,” he says.

AltAir Fuels is the first to license UOP’s process to produce HRJ. The Seattle-based company signed memorandums of understanding with 14 airlines in December to negotiate the purchase of up to 750 million gal. of camelina-derived fuel. This is to be produced at a facility in Anacortes, Wash., and would replace about 10% of the fuel consumed annually at Seattle-Tacoma International Airport. “Once ASTM approves the fuel, we can begin the permitting process,” he says, adding that construction will take 18 months.

The creation of AltAir illustrates the challenges of starting biofuel production. Sustainable Oils works by signing contracts with farmers to grow camelina that it will buy back at an agreed price. Farmers grow a specific strain of camelina developed by biotechnology company Targeted Growth. Sustainable Oils extracts the oil from camelina seeds, “but we hoped someone else would build the refinery,” says Todaro.

Eventually, to kick-start the market, Sustainable Oils decided to form AltAir as an independent company. The business plan is to build add-on units at traditional refineries. With 100-million-gal. capacity, these bolt-on facilities will each cost “a couple of hundred million dollars” and provide about 10% of the fuel required annually at an average-sized airport, he says.

A different business model is being pursued by St. Paul, Minn.-based JetE, which is proposing to sell small turnkey HRJ plants to farming cooperatives looking to add value to their feedstock. “Ultimately it is all about feedstock, and who controls it? Farmers. We can put them in the business of making fuel,” says Tim Kubista, senior vice president. JetE’s role includes bringing fuel buyers to the table.

JetE has licensed small-scale hydroprocessing technology from Danish company Haldor Topsoe and is offering a 7.5-million-gal.-per-year plant for $40 million and a 30-million-gal. plant for $85-90 million. Kubista is hopeful of a deal by year-end, and says the feedstocks that are economically viable and available in commercial quantities in the U.S. are crude corn oil from ethanol production, soybean oil and tallow.

While the near-term focus is on plant oils and animal fats as feedstocks, aviation is enamored of algae because it promises high-oil yields from small land areas and does not compete with food for land or water. Work is underway scaling up algae production in both open ponds and closed bioreactors, in a bid to drive down costs, but San Francisco-based Solazyme says it is ready to move into commercial-scale oil production using a different algae pathway.

Solazyme has adapted the fermentation process used to produce ethanol, replacing yeast with algae. Sugars produced from a wide range of feedstocks―switchgrass, corn stover, sugar cane, municipal waste and cellulosic biomassare fed to the algae, which convert the sugar to oil. The oil is then extracted from the algae and converted to HRJ using UOP’s process. Solazyme has delivered 1,500 gal. of algal HRJ to the U.S. Navy for engine testing.

The company says it is on track to be cost-competitive with petroleum-based fuel in 18-24 months, targeting $60-80 a barrel. “We should be producing quantities that can fill some demand in the aviation market in the next three years,” says CEO Jonathan Wolfson.

Solazyme is talking to airlines about long-term supply agreements and to refining partners about establishing a supply chain. “We are working with numerous partners to provide a rapid path to commercialization that includes access to feedstock and financing,” he says, noting the addition of U.S. agribusiness Bunge as a strategic investor “is an indicator of how we are thinking about feedstock . . . we are confident that the supply will be there.”

After playing a key role in the rapid progress of biofuels from idea to reality, UOP is turning its attention to new processes and feedstocks.

“We’ve made [bio-SPK] fuels from about 12 different types of natural oils,” says Jim Rekoske, vice president and general manager of UOP’s renewable energy business. “We are confident we can look at an oil and say what yield of jet fuel you will get from that feedstock.”

UOP’s process “is completely feedstock flexible,” Rekoske says, and can convert any natural oil with hydrocarbon chains of appropriate lengths into jet fuel. “A flexible process allows you to source the cheapest available oil.” The challenge now, he says, is in bringing together three different industries?agriculture, refining and transportation?to reach long-term agreements that will provide the confidence needed to scale up feedstock and fuel production. “That’s the process that is taking time.”

Feedstock flexibility will allow an HRJ fuel producer to switch to a higher-yield feedstock. “If the question is, do you want to invest in growing camelina if you can be supplanted in five years by algae, the answer is long-term agreements with customers and refiners. It’s just negotiation,” says Rekoske. He believes there has been significant progress, with two groups close to definitive supply agreements with airlines.

With approval for bio-SPKs now within sight, interest is shifting to more advanced biofuels, and there is growing excitement?and debate?over which pathways will be next to be approved. “Part of our work is to figure out what is next, what’s the most mature,” says AFRL’s Edwards. “It starts with people sending us fuels. We’re working on different feedstocks, different processes and fully synthetic fuels.”

Much of the work is focused on processes for producing jet fuel from ligno-cellulosic feedstocks such as forest, agricultural and municipal waste, which is available in huge quantities. UOP is working on upgrading pyrolysis oil to liquid fuel. Fast pyrolysis is the rapid decomposition of biomass in the presence of heat and absence of oxygen. The resulting bio-oil can be upgraded to fuel. “We are looking at a variety of different things for next-generation fuels. But there is a tremendous capacity to supply natural oils without going to biomass and other carbon sources,” argues Rekoske.

One of the most promising new pathways, Edwards says, is being called “alcohol oligomerization.” This starts with an alcohol-like ethanol or butanol, removes the oxygen and grows hydrocarbons from the molecules. Gevo, Virent and Swedish Biofuels are among the companies working on this “catalytic renewable jet” pathway. Brazilian biotechnology company Amyris, meanwhile, is pursuing an advanced fermentation process that goes direct from cellulosic biomass to liquid fuel using specially tailored microorganisms.

Richard Altman, executive director of the Commercial Aviation Alternative Fuels Initiative, says the catalytic, fermentation and pyrolysis renewable jet pathways are competing to be the next process approved by ASTM in the 2013 timeframe. ASTM, meanwhile, has formed a task force to look at fully synthetic fuels, called SKAs, for “synthetic kerosene with aromatics.”

Synthetic paraffinic kerosenes are limited to 50% blends by the need for aromatic hydrocarbons found in conventional jet fuel, but synthesized aromatics―or changes to engine seal materials―could allow 100% synthetic fuels. “We are doing a lot of work on fully synthetic fuels,” says Edwards. Honeywell and the FAA are working to determine by 2013-14 the minimum aromatics required in engines, says Rekoske, adding that “100% synthetic is still the goal.”
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