Title: Characterization and Catalytic Upgrading of Aqueous Stream Carbon from Catalytic Fast Pyrolysis of Biomass

Abstract

Catalytic fast pyrolysis (CFP) of biomass produces a liquid product consisting of organic and aqueous streams. The organic stream is typically slated for hydrotreating to produce hydrocarbon biofuels, while the aqueous stream is considered a waste stream, resulting in the loss of residual biogenic carbon. Here, we report the detailed characterization and catalytic conversion of a CFP wastewater stream with the ultimate aim to improve overall biomass utilization within a thermochemical biorefinery. An aqueous stream derived from CFP of beech wood was comprehensively characterized, quantifying 53 organic compounds to a total of 17% organics. The most abundant classes of compounds are acids, aldehydes, and alcohols. The most abundant components identified in the aqueous stream were C1-C2 organics, comprising 6.40% acetic acid, 2.16% methanol, and 1.84% formaldehyde on wet basis. The CFP aqueous stream was catalytically upgraded to olefins and aromatic hydrocarbons using a Ga/HZSM-5 catalyst at 500 degrees C. When the conversion yield of the upgraded products was measured with fresh, active catalyst, 33% of the carbon in the aqueous stream was recovered as aromatic hydrocarbons and 29% as olefins. The majority of the experiments were conducted using a molecular beam mass spectrometer and separate GC-MS/FID experiments were used tomore » confirm the assignments and quantification of products with fresh excess catalyst. The recovered 62% carbon in the form of olefins and aromatics can be used to make coproducts and/or fuels potentially improving biorefinery economics and sustainability. Spent catalysts were collected after exposure to varying amounts of the feed, and were characterized using multipoint-Brunauer-Emmett-Teller (BET) adsorption, ammonia temperature programmed desorption (TPD), and thermogravimetric analysis (TGA) to monitor deactivation of Ga/HZSM-5. These characterization data revealed that deactivation was caused by coke deposits, which blocked access to active sites of the catalyst and spent catalysts regained total activity after regeneration.« less

Authors:

Starace, Anne K. ^[1]; Black, Brenna A. ^[1]; Lee, David D. ^[1]; Palmiotti, Elizabeth C. ^[1]; Orton, Kellene A. ^[1]; Michener, William E. ^[1]; ten Dam, Jeroen ^[2]; Watson, Michael J. ^[2]; Beckham, Gregg T.  ^[1];

• Search DOE PAGES for author "Beckham, Gregg T."
• Search DOE PAGES for ORCID "0000-0002-3480-212X"

Magrini, Kimberly A. ^[1]; Mukarakate, Calvin  ^[1]

• Search DOE PAGES for author "Mukarakate, Calvin"
• Search DOE PAGES for ORCID "0000-0002-3919-7977"

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+ Show Author Affiliations

1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
2. Johnson Matthey Technology Centre, Billingham, Cleveland (United Kingdom)

Publication Date:

Mon Oct 23 00:00:00 EDT 2017

Research Org.:

National Renewable Energy Lab. (NREL), Golden, CO (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE), Sustainable Transportation Office. Bioenergy Technologies Office

OSTI Identifier:

1408085

Report Number(s):

NREL/JA-5100-70293
Journal ID: ISSN 2168-0485

Grant/Contract Number:  

AC36-08GO28308

Resource Type:

Accepted Manuscript

Journal Name:

ACS Sustainable Chemistry & Engineering

Additional Journal Information:

Journal Volume: 5; Journal Issue: 12; Journal ID: ISSN 2168-0485

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

09 BIOMASS FUELS; CFP AQUEOUS STREAMS; WASTEWATER TREATMENT; HZSM-5; COPRODUCTS; COKE FORMATION