New catalytic process to convert lignin into jet-range hydrocarbons
11 December 2015
Researchers at Washington State University (WSU) Tri-Cities have developed a catalytic process to convert corn stover lignin into hydrocarbons (C7–C18)—primarily C12–C18 cyclic structure hydrocarbons in the jet fuel range. The work is featured on the cover of the December issue of the RSC journal Green Chemistry.
The developer of the process, Bin Yang, an associate professor of biological systems engineering at WSU and his team are working with Boeing Co. to develop and test the hydrocarbons targeted to be jet fuel. Yang has filed for a patent on the process, with WSU as the assignee.
Lignin is an organic polymer that makes plants woody and rigid; after cellulose, it is the most abundant renewable carbon source on Earth. Ordinarily, it is wasted when plant biomass, including cellulose, is converted into biofuels such as ethanol.
Between 40 and 50 million tons of lignin are produced annually worldwide, mostly as a non-commercialized waste product, according to the International Lignin Institute.
Due to its availability, low oxygen to carbon (O/C) ratio, and markedly low total oxygen content compared to biomass-derived carbohydrates (~36% versus ~50%, respectively), lignin is a promising feedstock for production of renewable hydrocarbon fuels and chemicals. However, lignin’s native molecular structure is, approximately C800-C900—far higher than the carbon chain lengths required for fuel applications (~C6-C20). To be used as a source for fuel, the lignin must be depolymerized, its H/C ratio increased, and its O/C ratio must be further decreased.
To date, virtually no approach has proven successful for converting lignin into hydrocarbon liquids or chemicals.
Yang’s procedure involves the aqueous-phase hydrodeoxygenation (HDO) of dilute alkali-extracted corn stover lignin catalyzed by a noble metal catalyst (Ru/Al2O3) and acidic zeolite (H+-Y), yielding a range of hydrocarbons. The resulting product must be separated and purified to obtain the jet-fuel hydrocarbons.
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In addition to hydrocarbons suitable for jet turbine engines, Yang is using lignin to produce a variety of other chemicals and materials. Through two recent grants funded by the US Department of Energy, both headed by Texas A&M University, he leads WSU’s effort to produce lipids and bioplastics created from lignin.
He also is working with the nearby Pacific Northwest National Laboratory and the National Renewable Energy Laboratory in Colorado on projects to convert lignin into a range of chemicals, including supercapacitors.
Yang and his team’s research is supported by the Defense Advanced Research Projects Agency (DARPA) through the US Department of Defense, as well as the US Department of Energy, the National Science Foundation, the Sun Grant from the US Department of Transportation, the National Renewable Energy Laboratory and the Seattle-based Joint Center for Aerospace Technology Innovation.
Resources
Hongliang Wang, Hao Ruan, Haisheng Pei, Huamin Wang, Xiaowen Chen, Melvin P. Tucker, John R. Cort and Bin Yang (2015) “Biomass-derived lignin to jet fuel range hydrocarbons via aqueous phase hydrodeoxygenation” Green Chem. 17, 5131-5135 doi: 10.1039/C5GC01534K
US 20150099868 A1: Apparatus and process for preparing reactive lignin with high yield from plant biomass for production of fuels and chemicals
aqueous-phase hydrodeoxygenation
Might be more energy efficient than other processes.
Posted by: SJC | 11 December 2015 at 12:10 PM