Fischer-Tropsch Synthesis Catalyzed by Solid Nanoparticles at the Water/Oil Interface in an Emulsion System

Abstract

Fischer-Tropsch synthesis (FTS) was carried out in a water/oil mixture medium, using a Ru catalyst supported on a multi-walled carbon nanotube/MgO-Al2O3 hybrid as a catalyst support. The nanohybrid particles at the water/oil interface facilitated and stabilized the formation of water-in-oil emulsion, giving rise to an oil/emulsion/water trilayer liquid structure. FTS occurred at the emulsion phase with much higher conversion rates than those in oil single-phase reactions, yielding products with Anderson-Schulz-Flory distribution. Alkane-enriched hydrocarbons migrate to the top oil phase, while short alcohols remain in the bottom water phase. Thus, this multiphase liquid structure facilitates the separation of products according to their solubility in different phases. This significant advantage of combined reaction and separation is unique to the multiphasic system. In addition, differences in solubility could be used to enhance tolerance against impurities and catalyst poisons in the syngas feedstock. As a preliminary case study, hydrochloric acid and pyridine were chosen as model contaminants commonly found in biosyngas. It was found that their presence did not affect the catalytic activity as severely as could be expected in a conventional FTS process. Thus, emulsion-phase FTS could be beneficial to operations where syngas production such as biomass gasification and FTS are integrated. The several advantages of using emulsion systems in FTS are discussed in light of the current results.

Department(s)

Chemical and Biochemical Engineering

Comments

Financial support from the National Science Foundation (NSF)/Experimental Program to Stimulate Competitive Research (EPSCoR) Research Infrastructure Improvement Award (EPS 0814361) for the reaction part and from the U.S. Department of Energy (DOE)/EPSCoR (Grant DE SC0004600) for the emulsion and catalyst characterization part is gratefully acknowledged.

Keywords and Phrases

Anderson-Schulz-Flory distributions; Biomass Gasification; Liquid structures; Model contaminant; Nanohybrid particles; Solid nanoparticles; Water in oil emulsions; Water/oil interfaces, Catalyst poisoning; Catalyst supports; Emulsification; Emulsions; Fischer-Tropsch synthesis; Impurities; Solubility; Synthesis gas, Phase interfaces

International Standard Serial Number (ISSN)

0887-0624; 1520-5029

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2013 American Chemical Society (ACS), All rights reserved.

Publication Date

01 Oct 2013

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