Jump to main content
Jump to site search


Multistage torrefaction and in situ catalytic upgrading to hydrocarbon biofuels: analysis of life cycle energy use and greenhouse gas emissions

Abstract

A well-to-wheel life cycle assessment (LCA) model is developed to characterize the life cycle energy consumption and greenhouse gas emissions profiles of a series of novel multistage torrefaction and pyrolysis systems for targeted thermochemical conversion of short rotation woody crops to bio-oil and in situ catalytic upgrading to hydrocarbon transportation fuels, and benchmark the results against a base-case fast pyrolysis and hydrodeoxygenation (HDO) platform. Multistage systems utilize a staged thermal gradient to fractionate bio-oil into product streams consisting of distinct functional groups, and multi-step chemical synthesis for downstream processing of bio-oil fractions to hydrocarbon fuels. Results at the process scale reveal that multistage systems have several advantages over the base-case including: (1) ~40% reduction in process hydrogen consumption and (2) the product distribution for multistage systems are skewed towards longer carbon chain compounds that are fungible with diesel-range fuels. LCA reveals that the median Energy Return On Investment (EROI) and life cycle greenhouse gas (GHG) emissions for multistage systems range from 1.32 to 3.76 MJ-Fuel/MJ-Primary Fossil Energy and 17.1 to 52.8 gCO2e/MJ-Fuel respectively, over the host of co-product scenarios and allocation schemes analyzed, with fossil-derived hydrogen constituting the principle GHG and primary energy burden across all systems. These results are compelling and indicate that multistage systems exhibit comparatively higher gasoline/diesel-range fuel yield relative to current technology and produce a high quality infrastructure compatible hydrocarbon transportation fuel capable of achieving over 80% reduction in life cycle GHG relative to baseline petroleum diesel.

Back to tab navigation
Please wait while Download options loads

Supplementary files

Publication details

The article was received on 10 Mar 2017, accepted on 20 Apr 2017 and first published on 20 Apr 2017


Article type: Analysis
DOI: 10.1039/C7EE00682A
Citation: Energy Environ. Sci., 2017, Accepted Manuscript
  •   Request permissions

    Multistage torrefaction and in situ catalytic upgrading to hydrocarbon biofuels: analysis of life cycle energy use and greenhouse gas emissions

    G. G. Zaimes, A. W. Beck, R. J. Reddy, D. Resasco, S. Crossley, L. lobban and V. Khanna, Energy Environ. Sci., 2017, Accepted Manuscript , DOI: 10.1039/C7EE00682A

Search articles by author