Chemistry

Metal oxide supported Ni-impregnated bifunctional catalysts for controlling char formation and maximizing energy recovery during catalytic hydrothermal liquefaction of food waste

Document Type

Article

Abstract

Nickel (Ni)-impregnated metal oxide catalysts, Ni/CeZrOx, Ni/ZrO2, and Ni/CeO2, were investigated to maximize energy recovery and reduce char yield during catalytic hydrothermal liquefaction (CHTL) of food waste. Yields of char, biocrude, water soluble products, and gas were measured at 300 °C and 1 hour for both the parent oxides (CeZrOx, ZrO2, and CeO2) and the Ni-impregnated versions. Using Ni-based catalysts reduced the carbon-weighted char yield from 16-24% to 60%. Ni/ZrO2 and Ni/CeO2 show the greatest potential for controlling char growth and maximizing energy recovered from food waste. The crystalline structures of all three oxides were hydrothermally stable. Catalyst reuse tests indicate that the biocrude and char yields remained the same for the first and second use (within uncertainty) and that the catalyst retains its initial crystallinity and 93% of its initial Ni content. Molecular composition of biocrudes analyzed by the state-of-the-art analytical platforms (including GC-MS, GC × GC, FT-ICR MS, and 1H NMR) revealed minor differences in the chemical constituents of biocrudes obtained using different catalysts and provided some insight regarding reaction mechanism.

Publication Title

Sustainable Energy and Fuels

Publication Date

2-21-2021

Volume

5

Issue

4

First Page

941

Last Page

955

ISSN

2398-4902

DOI

10.1039/d0se01662d

Keywords

catalysts, cerium oxide, chemical analysis, crystallinity, food waste, liquefaction, mass spectrometry, metals, zirconia

Link to Full Text

Share

COinS