Oxidative Steam Reforming of Raw Bio-Oil over Supported and Bulk Ni Catalysts for Hydrogen Production

Abstract

Several Ni catalysts of supported (on La 2 O 3 -αAl 2 O 3 , CeO 2 , and CeO 2 -ZrO 2 ) or bulk types (Ni-La perovskites and NiAl 2 O 4 spinel) have been tested in the oxidative steam reforming (OSR) of raw bio-oil, and special attention has been paid to the catalysts' regenerability by means of studies on reaction-regeneration cycles. The experimental set-up consists of two units in series, for the separation of pyrolytic lignin in the first step (at 500 • C) and the on line OSR of the remaining oxygenates in a fluidized bed reactor at 700 • C. The spent catalysts have been characterized by N 2 adsorption-desorption, X-ray diffraction and temperature programmed reduction, and temperature programmed oxidation (TPO). The results reveal that among the supported catalysts, the best balance between activity-H 2 selectivity-stability corresponds to Ni/La 2 O 3 -αAl 2 O 3 , due to its smaller Ni 0 particle size. Additionally, it is more selective to H 2 than perovskite catalysts and more stable than both perovskites and the spinel catalyst. However, the activity of the bulk NiAl 2 O 4 spinel catalyst can be completely recovered after regeneration by coke combustion at 850 • C because the spinel structure is completely recovered, which facilitates the dispersion of Ni in the reduction step prior to reaction. Consequently, this catalyst is suitable for the OSR at a higher scale in reaction-regeneration cycles.

Coke formation and deactivation during catalytic reforming of biomass and waste pyrolysis products: A review

“…Nevertheless, a more stable behavior and better renderability of Ni catalyst can be achieved by using Ni-spinel, such as NiAl2O4 [354], bulk Ni [355] or alloys of Ni-Fe [356]. Li et al [357] have found that incorporating CeO2 (or MnO), traces Pt, and MgO to the Ni supported catalyst has a positive impact for having a more stable behavior trough reforming/regeneration cycles.…”

SrxTi1–xCoO3±δ Perovskite‐like Catalysts with Enhanced Activity for Hydrogen Production

“…Autothermal reforming (ATR) with oxygen in the feed stands out for its heat sustainability, as shown in Eq. 2 5, 6. However, oxygen in the ATR feed is normally consumed in the leading upstream zone of the fixed‐bed reactor with a high temperature (up to 1000 °C), and deactivation by oxidation and sintering of catalysts can be found over time 7.…”

Dry Reforming of Methane over NiLa-Based Catalysts: Influence of Synthesis Method and Ba Addition on Catalytic Properties and Stability

“…The world energy matrix is essentially based on the use of fossil fuels with an increasing share of natural gas; this factor, together with the improved efficiency of energy conversion systems, has largely contributed in the last 10-15 years to the mitigation of CO 2 emissions in the electric power sector worldwide. In order to impact on the CO 2 footprint of the chemical and transportation sectors, transition strategies have been developed by oil and energy companies which emphasize the crucial role of a growing exploitation of NG reserves for the production of fuels and chemicals through the indirect conversion into synthesis gas and platform intermediates like methanol [1][2][3][4].…”

“…Even though noble metals exhibit better catalytic performance and higher coke-resistance when compared to nickel catalysts, their high prices and low availability limit their industrial application [18,19]. Aiming to enhance the stability against coke formation and active phase sintering, nickel-based catalysts have been synthesized by diverse routes and on different supports [4,11,20].…”