Purdue team demonstrates proof-of-concept of H2Bioil process; liquid fuel range hydrocarbons from biomass

17 November 2014

H2Bioil concept. Venkatakrishnan et al. Click to enlarge.

Researchers at Purdue University report a proof-of-concept of a their novel consecutive two-step process (H₂Bioil) for the production of liquid fuel range hydrocarbons (C₄₊) with undetectable oxygen content from cellulose and an intact biomass (poplar). (Earlier post.)

Purdue University filed a patent application on the H2Bioil concept, which is based on fast-hydropyrolysis and downstream vapor-phase catalytic hydrodeoxygenation (HDO), in 2008. The process adds hydrogen into the biomass-processing reactor and is made possible by development of a new catalyst and the innovative reactor design. Findings are described in a research paper published online in the RSC journal Green Chemistry.

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The carbon recovery as C₁–C⁸⁺ hydrocarbons is ~73% (C₄₊ ~55%) from cellulose and ~54% (C₄₊ ~32%) from poplar.

The demonstration is a step toward commercialization. Because the process can produce hydrocarbons in a single tandem step, it clearly has a potential to have a positive impact on the biofuels sector. The successful lab-scale demonstration of the H2Bioil concept paves the way for rapid conversion of biomass species to liquid fuel and chemicals.

Furthermore, we envision that the process can be built on a distributed scale for widespread use. Ultimately, with proper design, this concept is amenable to providing mobile plants that could be transported from one biomass-available site to another.

The H2Bioil reactor is capable of processing all kinds of available biomass including wood chips, switch grass, corn stover, rice husks and wheat straw. It sidesteps a fundamental economic hurdle in biofuels: Transporting biomass is expensive because of its bulk volume, whereas liquid fuel from biomass is far more economical to transport. The technology could be used to process biomass into liquid fuel at agricultural sites with a mobile platform, and then transport it to a central refinery for further processing.

Critical to the technology is a new platinum-molybdenum catalyst and design of the hydropyrolysis reactor system. The new method offers advantages over conventional technologies because it produces biofuel from all biomass as opposed to a portion of the biomass such as cellulose or lignin only, Agrawal said.

Biomass along with hydrogen is fed into a high-pressure reactor and subjected to extremely fast heating, rising within a second to as hot as 500 ˚C.

The work is led by Agrawal; Fabio H. Ribeiro, the R. Norris and Eleanor Shreve Professor of Chemical Engineering; and W. Nicholas Delgass, the Maxine Spencer Nichols Emeritus Professor of Chemical Engineering, all at Purdue. The research paper was authored by doctoral student Vinod Kumar Venkatakrishnan, Delgass, Ribeiro and Agrawal.

The Purdue researchers previously invented an approach called a “hybrid hydrogen-carbon process,” or H2CAR. The research has been funded by the National Science Foundation and the Center for Direct Catalytic Conversion of Biomass to Biofuels (C3Bio), an Energy Frontier Research Center in Purdue’s Discovery Park funded by the US Department of Energy, Office of Science. C3Bio is directed by Professor Maureen McCann.

Resources

• Vinod Kumar Venkatakrishnan, W. Nicholas Delgass, Fabio H. Ribeiro and Rakesh Agrawal (2015) “Oxygen removal from intact biomass to produce liquid fuel range hydrocarbons via fast-hydropyrolysis and vapor-phase catalytic hydrodeoxygenation,” Green Chem. doi: 10.1039/C4GC01746C