Research Article pubs.acs.org/journal/ascecg
Carbon Footprint Analysis of Gasoline and Diesel from Forest Residues and Corn Stover using Integrated Hydropyrolysis and Hydroconversion Jiqing Fan,*,† John Gephart,‡ Terry Marker,§ Daniel Stover,∥ Ben Updike,† and David R. Shonnard† †
Department of Chemical Engineering and the Sustainable Futures Institute, Michigan Technological University, 1400 Townsend Drive, Houghton, Michigan 49931, United States ‡ North Shore Forest Products, 5322 Grand Avenue, Duluth, Minnesota 55807, United States § Gas Technology Institute, 1700 S Mount Prospect Road, Des Plaines, Illinois 60018, United States ∥ Cargill Inc, Minneapolis, Minnesota 55440, United States S Supporting Information *
ABSTRACT: With an increasing focus on renewable fuels, it is vital to understand the environmental impacts from various alternative transportation fuel products and processes under development. This study analyzes greenhouse gas (GHG) emissions of renewable gasoline and diesel produced by the integrated hydropyrolysis and hydroconversion (IH2) process at an existing petroleum refinery in Memphis, TN, USA. In this study, we considered forest residues from the southeastern US and corn stover from the Midwest as the two feedstocks. H2 required for the process is either imported from a steam methane reformer using natural gas or produced from C1−C3 gas coproducts of the IH2 process. Life cycle GHG emission savings of 67−86% were calculated for IH2 gasoline and diesel compared to their fossil counterparts, depending on feedstock, transport and H2 sources. Monte Carlo simulations were conducted to assess the impact of input parameter uncertainty on the final GHG emission results. The impact of applying biochar coproduct as a soil amendment and soil carbon change due to residue harvest were also studied. KEYWORDS: Hydropyrolysis, Hydroconversion, Forest residue, Corn stover, Greenhouse gas, Life cycle assessment
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INTRODUCTION
Catalytic hydropyrolysis or integrated hydropyrolysis and hydroconversion (IH2) provides an alternative approach to directly convert biomass to hydrocarbon gasoline and diesel. Catalytic hydropyrolysis is carried out in a fluidized bed at relatively low hydrogen pressure (20−35 bar) and moderate temperature (350−480 °C). This process yields a dark and opaque liquid with low oxygen content (3−6 wt %) and TAN (
