NextFuels targets palm oil waste for advanced biofuel production
California-based NextFuels has emerged from stealth mode and is unveiling its strategy to produce advanced biofuels from wet, unprocessed agricultural waste via a hydrothermal process originally developed by Shell in the 1980s. The company, a subsidiary of biofuel trading company Enagra Inc., is currently focused on converting agricultural waste from palm oil production in Southeast Asia into drop-in coal and petroleum replacements.
According to Ralph Overend, chief scientist of NextFuels, the company’s bio-liquefaction technology reacts biomass within liquid water at high temperatures and pressures to produce a putty-like substance referred to as GreenCrude, which can be either burned as a coal replacement or further refined into transportation fuels at traditional oil refineries. The reaction is completed under conditions ranging from 300 to 330 degrees Celsius and at pressures of 200 to 230 atmospheres, he continued.
While pyrolysis technologies require the use of dry biomass, Overend stressed that the NextFuels’ hydrothermal process can take in wet biomass, thereby eliminated the costly step to dry feedstock. The ability to take in wet feedstocks makes this technology particularly appropriate for the processing of palm oil residues, which can consist of 60 to 70 percent water.
Another difference between NextFuels’ hydrothermal process and pyrolysis technologies is the oxygen content of the resulting fuel. “Typically, if you look at the organic materials from the fast pyrolysis, you’d find about 35 or 40 percent oxygen, compared with the original 46 to 50 percent oxygen that the biomass had,” Overend said. “In the case of hydrothermal technologies, depending on the conditions, you can get down in the range of 20 to 15 percent oxygen content.”
Prior to NextFuels’ involvement with the technology, Shell operated the process on a pilot scale. According to Overend, the pilot plant operated from 2004 through 2008. During that time, the equipment, which can produce 5 to 8 barrels of green crude oil per day, ran for more than 1,000 hours. “The financial situation of the world collapsed in 2008, and so did the project they were developing,” Overend said. As a result, the pilot plant was disassembled. NextFuels is currently in the process of redesigning and reassembling the pilot plant.
“We are trying to move on the fast track, so we anticipate that the rebuild will be complete by the end of the second quarter of next year,” Overend said, noting that the pilot will be rebuilt in the Netherlands. Palm oil residue will be shipped to the facility from Southeast Asia for testing purposes.
According to Overend, the pilot facility will operate for eight to 12 months. During that time, work will also begin on a full-scale commercial demonstration plant. That facility will be located in Asia. Infomration published by NextFuels states that its commercial-scale facilities are expected to produce approximately 1,000 barrels of oil equivalent per day, via four 250-barrel-per-day modules.
Regarding NextFuels’ business plan, Overend said the company is currently pursuing a joint venture model that aims to build, own and operate production facilities in partnership with palm oil producers. He also said that the company would likely not be averse to pursuing a licensing strategy in the future. Additional feedstocks identified by NextFuels’ for possible future development include sugar beet residues and sugarcane bagasse.