Well-To-Wheels Analysis of Fast Pyrolysis Pathways with the GREET Model.

Accession Number

DE2012-1036090

Publication Date

Dec 2011

Media Count

76p

Personal Author

A. Elgowainy J. Han J. B. Dunn M. O. Wang R. I. Palou-Rivera

Abstract

The pyrolysis of biomass can help produce liquid transportation fuels with properties similar to those of petroleum gasoline and diesel fuel. Argonne National Laboratory conducted a life-cycle (i.e., well-to-wheels (WTW)) analysis of various pyrolysis pathways by expanding and employing the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The WTW energy use and greenhouse gas (GHG) emissions from the pyrolysis pathways were compared with those from the baseline petroleum gasoline and diesel pathways. Various pyrolysis pathway scenarios with a wide variety of possible hydrogen sources, liquid fuel yields, and co-product application and treatment methods were considered. At one extreme, when hydrogen is produced from natural gas and when bio-char is used for process energy needs, the pyrolysis-based liquid fuel yield is high (32% of the dry mass of biomass input). The reductions in WTW fossil energy use and GHG emissions relative to those that occur when baseline petroleum fuels are used, however, is modest, at 50% and 51%, respectively, on a per unit of fuel energy basis. At the other extreme, when hydrogen is produced internally via reforming of pyrolysis oil and when bio-char is sequestered in soil applications, the pyrolysis-based liquid fuel yield is low (15% of the dry mass of biomass input), but the reductions in WTW fossil energy use and GHG emissions are large, at 79% and 96%, respectively, relative to those that occur when baseline petroleum fuels are used. The petroleum energy use in all scenarios was restricted to biomass collection and transportation activities, which resulted in a reduction in WTW petroleum energy use of 92-95% relative to that found when baseline petroleum fuels are used. Internal hydrogen production (i.e., via reforming of pyrolysis oil) significantly reduces fossil fuel use and GHG emissions because the hydrogen from fuel gas or pyrolysis oil (renewable sources) displaces that from fossil fuel natural gas and the amount of fossil natural gas used for hydrogen production is reduced; however, internal hydrogen production also reduces the potential petroleum energy savings (per unit of biomass input basis) because the fuel yield declines dramatically. Typically, a process that has a greater liquid fuel yield results in larger petroleum savings per unit of biomass input but a smaller reduction in life-cycle GHG emissions. Sequestration of the large amount of bio-char co-product (e.g., in soil applications) provides a significant carbon dioxide credit, while electricity generation from bio-char combustion provides a large energy credit.

Keywords

Biomass feedback
Biomass pyrolysis
Emissions regulation
Figures
Greenhouse gases
Greenhouse Gases Regulated Emissions and Energy Use in Trans
Life cycles analyses
Organic wastes
Product upgrading
Pyrolysis
Pyrolysis pathways
Tables (Data)
Transportation energy use
Well-to-Wheels Analysis


$48.00-COLOR DOCUMENT

Source Agency

Technical Information Center Oak Ridge Tennessee

NTIS Subject Category

97K - Fuels
68C - Solid Wastes Pollution & Control
85H - Road Transportation

Corporate Author

Argonne National Lab., IL. Energy Systems Div.

Document Type

Technical report

Title Note

N/A

NTIS Issue Number

1219

Contract Number

DE-AC02-06CH11357

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