(650a) Life Cycle Assessment of Jet Fuel Produced from IH2-Cool Gtl Integrated Process

Biofuels with lower associated GHG emissions could help to address issues associated with climate change in a sustainable manner. Woody biomass is a source for biofuels that is widely available (1 billion metric tons/year) [1]. Because of its lignocellulosic nature, woody biomass requires biochemical and thermochemical conversion technologies and upgrading steps to be transformed into “drop-in” fuels. Many potential sources of renewable methane biogas are also available, including food waste, animal manures, and wastewater treatment sludge, and the use of these biogas streams can often be environmentally favorable for avoiding methane emissions [2]. The integrated hydropyrolysis–hydroconversion plus Cool GTL process (IH2 Plus Cool GTL) is a thermochemical process for the conversion of a broad range of biomass types into a wide range of liquid hydrocarbon biofuels. The Cool GTL sub-process can also be used to convert a biogas stream of CO₂/CH₄ to renewable fuels.

This presentation will report on the current life cycle assessment results of a DOE-funded project led by GTI with collaborators from PSRI, Hatch Engineering, Veolia, Synsel Energy, and Michigan Technological University. The project team is working to understand the implications of integrated IH2-Cool-GTL processing of both wood-derived biogas and biogas from MSW landfill collection or anaerobic digestion of food waste and animal manure mixtures. Commercial-scale process modeling from Hatch project partners served as the foundation for the LCA study, combined with peer-reviewed reports and GTI information on the production of different renewable feedstocks and IH2 processing, respectively. Greenhouse gas (GHG) emissions and fossil energy demand are the primary environmental impacts of interest, although water use will also be quantified in the project. Initial LCA results indicate that biofuels can be produced with either feedstock that offer significant environmental improvements compared to fossil fuels. This work will also highlight the potential benefits of utilizing a novel electric reformer instead of a traditional gas-fired reformer.

Key LCA results show that production of hydrocarbon biofuels from the IH2 Plus Cool GTL process converting forest residue biomass produces 45.2 g CO₂ eq / MJ biofuel when H2 is produced using steam fossil methane reforming (SfMR), which is a 50% reduction compared to fossil aviation fuel. For a case where renewable H2 and electricity are utilized in the process, greenhouse gas emissions reduce to 26.4 g CO₂ eq / MJ biofuel. Finally, when the Cool GTL process is operated in isolation to produce biogas from anaerobic digestion of mixtures of food waste and cattle manure, hydrocarbon biofuel emissions are -338.8 g CO₂ eq / MJ liquid hydrocarbon biofuel mainly due to avoiding landfill and conventional manure management emissions.

References

[1] Langholtz, et al. (2016). 2016 Billion-ton report: Advancing domestic resources for a thriving bioeconomy, Volume 1: Economic availability of feedstock. Oak Ridge National Laboratory, Oak Ridge, Tennessee, managed by UT-Battelle, LLC for the US Department of Energy, 2016, 1-411.

[2] Ankathi, S.K.; Potter, J.S.; Shonnard, D.R. (2018) Carbon footprint and energy analysis of Bio-CH4 from a mixture of food waste and dairy manure in Denver, Colorado. Environ. Prog. Sustain., 37, 1101-1111.