(346a) Carbon Footprint Analysis of Gasoline and Diesel from Forest Residues and Algae Using Integrated Hydropyrolysis and Hydroconversion Plus Fischer-Tropsch

Authors: 
Winjobi, O., Michigan Technological University
Hossein Tavakoli, H., Michigan Technological University
Handler, R., Michigan Technological University
Marker, T., Gas Technology Institute
Shonnard, D. R., Michigan Technological University
Klemetsrud, B., University of North Dakota
Roberts, M., Gas Technology Institute
Carbon Footprint Analysis of Gasoline and Diesel from Forest Residues and Algae using Integrated Hydropyrolysis and Hydroconversion Plus Fischer-Tropsch (IH2® Plus cool GTL™).

Olumide Winjobi1, Hossein Tavakoli2, Bethany Klemenstrud3, Robert Handler1, Terry Marker4, Michael Roberts4, and David Shonnard1.

1 Department of Chemical Engineering and the Sustainable Futures Institute, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA

2 Department of Civil and Environmental Engineering, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA

3 Department of Chemical Engineering, University of North Dakota, 243 Centennial Dr. Stop 7101, Grand Forks, ND 58202, USA

4 Gas Technology Institute, 1700 S Mount Prospect Road, Des Plaines, Illinois 60018, USA

To address the dual challenge of meeting the rising energy demand while reducing environmental impacts associated with the production and consumption of fossil fuels, it is vital also to understand the environmental impacts from the various alternative transportation fuel products and processes being developed to complement the current fossil-derived fuels. This study evaluated the greenhouse gas (GHG) emissions and the cumulative energy demand (CED) associated with the production of ‘drop-in’ renewable fuels produced by the IH2® Plus cool GTL™ using forest residues and algal biomass augmented with natural gas as feedstock. The IH2® Plus cool GTL™ developed by GTI is a modification to the previous IH2® process also developed by GTI, to achieve a higher yield of biofuels relative to the IH2® process. The IH2® Plus cool GTL™ is a hydropyrolysis, hydroconversion combined with Fischer-Tropsch technology for converting a broad range of biomass types into liquid hydrocarbon transportation fuels spanning the range of diesel and gasoline.

The previous IH2® process uses the biogenic C1-C3 gases produced in the process as feedstock within the steam methane reformer to generate the hydrogen required in the process. However, in the modified IH2® Plus cool GTL™, the biogenic C1-C3 gases are initially processed through a dry reformer to generate syngas that is subsequently processed through a Fischer Tropsch reactor to generate liquid biofuel products, increasing the gasoline and diesel yield from 26 to 38%. Due to the use of the biogenic C1-C3 gases to boost the yield of biofuels in the IH2® Plus cool GTL™, the hydrogen required in the process is from an external source increasing; the amount of fossil fuel used within the process relative to the previous IH2®. This LCA compared the IH2® Plus cool GTL™ to the original base case studied previously by our group (Fan et al. 2015). This work also evaluated the ability of the biofuel produced from the IH2® Plus cool GTL™ to still qualify for a renewable identification number with the addition of fossil methane being added as feedstock.

From our study, a life cycle GHG emission savings of 63.3% was estimated for the optimized IH2® Plus cool GTL™ relative to fossil-derived fuel for forest residue feedstock. Higher emission relative to fossil-derived fuel was estimated for algal feedstock for the IH2® and IH2® Plus cool GTL™ processes. However, GHG savings of about 42% can be potentially achieved if the IH2® Plus cool GTL™ process is in an area with low GHG intensity electricity grid.

Reference

Fan, Jiqing, John Gephart, Terry Marker, Daniel Stover, Ben Updike, and David R. Shonnard. "Carbon footprint analysis of gasoline and diesel from forest residues and corn stover using integrated hydropyrolysis and hydroconversion." ACS Sustainable Chemistry & Engineering 4, no. 1 (2015): 284-290.

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