Steam Reforming of Bio-Compounds with Auto-Reduced Nickel Catalyst

Abstract

Abstract:As an extension of chemical looping combustion, chemical looping steam reforming (CLSR) has been developed for H 2 production. During CLSR, a steam reforming (SR) process occurs following the reduction of catalysts by the reforming feedstock itself (termed "auto-reduction"), as opposed to a separate, dedicated reducing agent like H 2 . This paper studied SR performances of four common bio-compounds (ethanol, acetone, furfural, and glucose) with a nickel catalyst that had undergone auto-reduction. A packed bed reactor was used to carry out the experiment of auto-reduction and subsequent SR. The effects of temperature and steam to carbon ratio (S/C) on the carbon conversions of the bio-compounds to gases and yields of gaseous products were investigated. The carbon deposition on spent catalysts was characterized by CHN elemental analysis and Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX). The SR performance with the auto-reduced catalyst was close to that with the H 2 -reduced catalyst. In general, an increase in temperature or S/C would lead to an increase in H 2 yields. The dependence of SR performance on temperature or S/C was specific to the type of bio-compounds. Accordingly, the main bottlenecks for SR of each bio-compound were summarized. A large amount of CH 4 existed in the reforming product of ethanol. Severe carbon deposition was observed for SR of acetone at temperatures below 650 • C. A high thermal stability of furfural molecules or its derivatives restricted the SR of furfural. For SR of glucose, the main problem was the severe agglomeration of catalyst particles due to glucose coking.

Performance of an Auto-Reduced Nickel Catalyst for Auto-Thermal Reforming of Dodecane

“…The performances of Ni-based monolith reforming catalysts for the SR, POx, and ATR of n-dodecane have also been evaluated [14][15][16]. In particular, the catalytic properties and carbon-decomposition resistance of nickel-alumina catalysts have been studied in the SR reactions of various hydrocarbon fuels [17][18][19][20][21]. Nickel-alumina-based catalysts are usually prepared by impregnation or co-precipitation, with the former method being simpler than the latter.…”

Hydrogen production from bio-oil: A thermodynamic analysis of sorption-enhanced chemical looping steam reforming

“…In this study, furfural was also selected because its molecular formula (C5H4O2) closely matches that of the moisture-free bio-oil model mixture shown in Table 3. Furfural has been used as a model compound by several authors [38,59]. Remón et al [60] used a statistical analysis to identify that acetic acid and furfural were the compounds which had the most significant effect on bio-oil reforming performance.…”

“…The CLSR concept has also been applied to alternative fuels from bioenergy sources, including glycerol [33,34], waste lubricating oil [35], and bioethanol [36]. This also includes the CLSR of bio-oil and its model compounds on nickel-based OTMs [37][38][39].…”

Autothermal Reforming of Acetic Acid to Hydrogen and Syngas on Ni and Rh Catalysts

“…The aim of this study is to test the autothermal reforming of acetic under thermodynamically determined optimum conditions to measure conversion, product gas composition and carbon deposition using cobalt-free catalysts with composition and structure with industrial reforming relevance in packed and structured bed. Particulates from broken pellets of Ni on Al 2 O 3 and of CaO-Al 2 O 3 quadralobe raschig rings, were already tested on HAc feedstock for SR [28][29][30], and chemical looping steam reforming [31], with sorption enhancement [32]. We compare these catalysts in packed bed in the same ATR conditions with made in house Rh-Al 2 O 3 powder as well as structured catalysts made by TST Ltd., Hull, UK, i.e., Rh-Al 2 O 3 and Rh/Ce-Al 2 O 3 washcoated honeycomb cordierite monoliths.…”