Title: Biomass Catalytic Pyrolysis on Ni/ZSM-5: Effects of Nickel Pretreatment and Loading

Abstract

Here in this work, Ni/ZSM-5 catalysts with varied nickel loadings were evaluated for their ability to produce aromatic hydrocarbons by upgrading of pine pyrolysis vapors. The effect of catalyst pretreatment by hydrogen reduction was also investigated. Results indicate that the addition of nickel increases the yield of aromatic hydrocarbons while simultaneously increasing the conversion of oxygenates, relative to ZSM-5, and these effects are more pronounced with increasing nickel loading. Additionally, while initial activity differences were observed between the oxidized and reduced forms of nickel on ZSM-5 (i.e., NiO/ZSM-5 versus Ni/ZSM-5), the activity of both catalysts converges with increasing time on stream. These reaction results coupled with characterization of pristine and spent catalysts suggest that the catalysts reach similar active states during catalytic pyrolysis, regardless of pretreatment, as NiO undergoes in situ reduction to Ni by biomass pyrolysis vapors. This reduction of NiO to Ni was confirmed by reaction results and characterization by NH₃ temperature-programmed desorption, temperature-programmed reduction, and X-ray diffraction. This finding is significant in that the ability to reduce or eliminate the need for a pre-reaction H₂ reduction of Ni-modified zeolite catalysts could reduce process complexity and operating costs in a biorefinery-based vapor-phase upgrading process to produce biomass-derived fuelsmore » and chemicals. The ability to monitor catalyst activity in real time with a molecular beam mass spectrometer used to measure uncondensed, hot pyrolysis vapors allows for an improved understanding of the mechanism for improved activity with Ni addition to ZSM-5, which is attributed to the ability to prevent deactivation by deposition of coke and capping of zeolite micropores.« less

Authors:

Yung, Matthew M. ^[1]; Starace, Anne K. ^[1]; Mukarakate, Calvin ^[1]; Crow, Allison M. ^[1]; Leshnov, Marissa A. ^[1]; Magrini, Kimberly A. ^[1]

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+ Show Author Affiliations

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

Publication Date:

Mon Apr 25 00:00:00 EDT 2016

Research Org.:

National Renewable Energy Laboratory (NREL), Golden, CO (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Workforce Development for Teachers and Scientists (WDTS); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Sustainable Transportation Office. Bioenergy Technologies Office

OSTI Identifier:

1278317

Report Number(s):

NREL/JA-5100-66483
Journal ID: ISSN 0887-0624

Grant/Contract Number:  

AC36-08GO28308

Resource Type:

Accepted Manuscript

Journal Name:

Energy and Fuels

Additional Journal Information:

Journal Volume: 30; Journal Issue: 7; Journal ID: ISSN 0887-0624

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

09 BIOMASS FUELS; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; nickel loadings; aromatic hydrocarbons; pine pyrolysis vapors; biomass; pyrolysis; vapor phase upgrading; acidity; ZSM-5; nickel; reduction