Jetting on Biofuels

ClearFuels and Rentech are integrating their technologies for a demonstration facility that will produce drop-in renewable fuels, one of several developments taking shape in the advanced biofuels industry.
By Lisa Gibson | May 31, 2010
By the end of 2011, Rentech Inc. and ClearFuels Technology Inc. will have an integrated demonstration biorefinery that will serve as a model for their commercial-scale plans at sugar mills and wood products facilities. The two companies' technologies complement each other perfectly, they say, and the project will have a significant impact on the advanced biofuels industry.

The partnership will facilitate the installation of ClearFuels' biomass gasification system in Rentech's Commerce City, Colo., product demonstration unit (PDU). The gasifier will be attached to Rentech's syngas-to-liquid technology, which is based on the Fisher-Tropsch process. The PDU has been producing drop-in synthetic fuels from natural gas but the integration will allow production of fully renewable fuels from wood waste, sugarcane bagasse and other virgin biomass.

"Clearly, we think it is a major step forward to show essentially a shoot-to-tank demonstration from wood waste and sugarcane bagasse to RenDiesel and RenJet coming out the back end of the plant," says Harold Wright, Rentech's chief technology officer. The fuel produced currently with Rentech's technology is certified and ASTM-approved. RenJet was tested in April on an engineering validation flight by United Airlines, marking the first time a commercial airline has used synthetic fuel in flight, according to Rentech, although that fuel was made with natural gas. "We're substituting CO (carbon monoxide) and hydrogen from biomass," says ClearFuels CEO Eric Darmstaedter. "It doesn't matter where it comes from. The end product-the fuel-is the same. The fuel is already certified, whether it comes from coal, natural gas or biomass, it doesn't matter. Once we integrate with Rentech, it's a fully renewable fuel."

How the Process Works

Rentech believes its PDU is the only fully integrated synthetic transportation fuels facility in the U.S., producing about 420 gallons per day of fuels and chemicals. The technology uses a cheaper, proprietary iron-based catalyst and has a unique proprietary design, Wright says. "The beauty of our technology is it will work on a wide variety of renewable feedstocks as well as fossil-based feedstocks like natural gas," he says. Rentech chose ClearFuels' technology from a pool of more than 200 candidates because it has the capacity to maximize liquid yields and hasn't been deployed on a demonstration scale, according to Wright. "We had made an investment in ClearFuels' technology because of its ability to integrate well in an integrated biorefinery to produce high volumes of liquids," he explains.

ClearFuels' gasifier, dubbed High Efficiency Hydrothermal Reformer, is characterized as an indirect-fired steam reformer. With steam instead of oxygen or air, the system does not process nitrogen and needs no oxygen plant for operation, Darmstaedter says. It also allows for control of the residence time of the biomass and steam inside the reformer to adjust the syngas characteristics without redesigning the reformer. "We can operate it in one configuration to make 65 percent hydrogen," he explains. "In another configuration, we can make 40 percent hydrogen and 40 percent carbon monoxide. That's the same reformer." ClearFuels focuses only on unprocessed biomass such as crop residues, corn stover, sawdust and bark to allow for the simplest possible process and operation.

Coupling the two technologies results in the highest yield at the lowest cost for the best fit. "It's a great integration of our technology to theirs," Darmstaedter says. "We just happened to come together and see the fit." The project received $23 million from the U.S. DOE, and is one of 19 biorefinery endeavors to receive a total of $564 million from the American Recovery and Reinvestment Act to accelerate construction and operation of pilot, demonstration and commercial-scale systems.

"Our focus on advanced biofuels really has been one that's based on energy independence, and the idea is to replace foreign sources of fuel with domestic sources of fuel," says Valri Lightner, acting biomass program manager for the DOE. "Biofuels offer a near-term, clean, domestic source of liquid transportation fuel." The program's overall goals include achieving energy security, developing clean energy, advancing science and technology, and creating jobs, she says, adding that biofuels support all of them.

The DOE is currently cost-sharing 27 biorefinery projects, one of which is operating now-Verenium Corp.'s 1.4 million-gallon-per-year cellulosic ethanol plant in Jennings, La.-and the rest scheduled for operation by 2011 or 2013, Lightner says. The ARRA funding recipients were chosen through a four-step process beginning with a compliance review, which includes basic criteria such as ensuring all the proper forms were completed and submitted. Next is the technical merit review, where external experts evaluate the technical merit and rationale for the project, ensure it demonstrates credible economics and a competitive advantage, and assess the project management and execution. The policy review by DOE staff follows, ensuring geographic and technological diversity, and evaluating how well the project fits the DOE portfolio as well as its ability to meet the ARRA schedule. Last, a selection official makes the final decision based on all the criteria. Sustainability is an important aspect of a project's viability, Lightner emphasizes, saying the department considers 100 million dry metric tons per year of available feedstock to be a good standard.

"What we're really looking to do in these projects is to validate both the cost and the technology," Lightner says, adding that it helps bridge the "Valley of Death" between a proven concept at laboratory scale and enablement of a commercial reality in the future. Financers look for projects that are proven at one-tenth to one-fiftieth of commercial scale with data over a period of time, she explains. "We're trying to assist these companies in getting the data that would be necessary for them to go out and get private financing for the commercial replication."

When awarding money, the DOE favors fuels that meet the renewable fuels standard, including the greenhouse gas (GHG) reduction requirements, so the scale-ups can qualify toward the standard, Lightner says. Rentech's fuels meet the requirements, Wright says, reducing nitrogen dioxide, sodium oxide, particulate matter, carbon monoxide and tailpipe carbon emissions. When made from biomass, the fuels also have low life-cycle GHG emissions. "We think that the fuels meet a demand for cleaner fuels from the tailpipe perspective, but also meet the needs of cleaner fuels from the overall carbon emissions perspective," he says.

Wright adds that Rentech's fuels can be used today in planes, trains and automobiles. "We think that, because we have the ability to make drop-in fuels-diesel and jet fuel-that will fit into today's pipeline and today's infrastructure and today's engines, that this will be a major step forward for the industry," Wright says. "There will be other players in the industry, but many don't produce drop-in fuels. I think there will be a lot of interest in these drop-in fuels as we go forward." Not only that, but Rentech's fuels can be produced cost-competitively and at commercial scale, adds Julie Dawoodjee, Rentech's vice president of investor relations and communications.

Rentech now has a 25 percent strategic ownership interest in ClearFuels and the companies plan to polish their process during the demonstration, using its success as a blueprint for commercial biorefineries co-located with sugar mills and wood products facilities. The setup would allow for readily available feedstock with little transportation costs.

Branching Out

The first such project is planned for Hughes Hardwood International Inc. in Collinwood, Tenn., slated for operation by early 2014. The memorandum of understanding (MOU) specifies Hughes Hardwood will supply 1,000 dry tons of wood products per day for the production of about 16 million gallons of synthetic jet or diesel fuel and 4 million gallons of naphtha per year, along with about 8 megawatts of renewable power. The wood products will be mostly byproducts and waste from Hughes Hardwood, but may include slash and other residues harvested directly from the forest, Darmstaedter says. The only difference in the gasifier from demonstration to commercial scale is the number of tubes in the reformer, altering the capacity from 20 tons per day to 250 tons per day. The commercial systems will utilize four 250-ton-per-day modules.

"If the demonstration is successful, the next step is a commercial plant," Darmstaedter says, adding that he fully expects positive results and is in discussions with more possible co-location partners. "We're confident enough in the expected outcome of the demonstration that we're in project development on four commercial facilities, one of which we've announced." Darmstaedter believes ClearFuels' technology could be a good fit for other syngas-to-liquid processes, too, allowing for a wider imprint on the advanced biofuel market. "We won't fit with every application, but there are enough of them out there where we think we do fit well, where we think we'll help make a difference."

Rentech is working on several projects separate from ClearFuels as well, developing two production facilities, both of which already have off-take agreements with airlines. The proposed Strategic Fuels and Chemicals Complex near Natchez, Miss., would use fossil fuel feedstock such as natural gas to produce about 30,000 barrels per day of synthetic fuels and chemicals, while exporting more than 120 megawatts of power. Thirteen domestic and international airlines have signed MOUs for a fuel supply from the facility.

The proposed Rialto Renewable Energy Center in Rialto, Calif., would produce about 640 barrels of RenDiesel per day from urban woody green waste and export about 35 megawatts of power. The facility will employ Rentech's technology, coupled with the SilvaGas biomass gasification system. Rentech has multiyear agreements with eight domestic airlines to supply up to 1.5 million gallons per year of fuel for ground service equipment at Los Angeles International Airport (LAX) beginning in late 2012, when the facility is expected to go on line. "That allows the airlines at the airport to meet all of their environmental regulations without changing their ground service fleet," Wright emphasizes. "There are emissions issues around LAX and so they're under some mandates to reduce those and this fuel allows them to meet those mandates without actually changing any of the engines or any of the equipment they have on the ground today."

United Airlines will purchase 5,500 gallons per month of RenDiesel from Rialto for use in vans, trucks and specialized aircraft support equipment such as aircraft tugs, ground power support units and forklifts, according to United spokesman Mike Trevino. "From a business standpoint, United and other airlines at LAX have the opportunity to utilize a domestically produced fuel that does not depend on overseas crude oil, and hopefully will be available at a stable price," he says. The agreement will lower United's carbon footprint by 1.8 million pounds annually and, when combined with its addition of electric-powered vehicles, will bring emissions from United's ground equipment at LAX close to zero.

Driving Development

Progress in the advanced biofuels industry may not be speeding up, but the recent developments are encouraging, according to Michael McAdams, president of the Advanced Biofuels Association. "I'm delighted to see the development," he says. "We've been waiting for it and now we're actually seeing some commercial demonstrations being brought forward." McAdams cites a 75 MMgy Dynamic Fuels LLC renewable diesel plant in Geismar, La., that is nearly complete. A 50/50 joint venture between Tyson Foods Inc. and Syntroleum will convert Tyson's large byproduct stream of beef tallow, pork lard, chicken fat and various greases to fuel.

But even with all the recent progress, the advanced biofuels industry could use a boost, one that could come in several forms, such as an investment tax credit or continued funding from the DOE, which has exhausted its integrated biorefinery funding for 2010-'11. "The No. 1 obstacle is financing," McAdams says, adding that mature technologies are emerging from the point of having been demonstrated in a lab or small pilot. "The roadblock has been financing the first new plants because the appetite in the loaning community has been very slow to react to funding the first type of any technology and so what you see that's exciting in the biofuels space, in the bioproducts space, are some things that are the first of a kind."

Companies such as ClearFuels and Rentech that received funding get a giant boost, enabling scale-up and possibly attracting more investors. "They should be very excited," McAdams says. "We're excited about this development. This shows the deployment of these new technologies. It shows cross-partnership and it moves us one step closer to commercializing that kind of development."

Wright agrees. "The future's bright for renewable diesel and renewable jet fuel," he says. BIO

Lisa Gibson is a Biomass Magazine associate editor. Reach her at or (701) 738-4952.