An effect blending of acetone and acetic acid as bio-oil model compound for steam reforming reaction over Ce doped LaNi0.8Fe0.2O3-based perovskite

Abstract

Conversion of biomass tar to useful hydrogen-rich syngas will solve environmental issues related to tar emission as well as increase the overall efficiency of biomass conversion. There are various catalysts to achieve that. In this study, La1-xCexNi0.8Fe0.2O3 (0 ≤ x ≤ 1) is selected, and acetic acid has been used as a biomass tar model. Fixed-bed reactor was used for this investigation, while the catalyst characterization has been done mainly by X-ray Adsorption spectroscopy (XAS), X-ray diffraction (XRD), CO2-temperature programmed desorption (TPD). The results showed that La0.8Ce0.2Ni0.8Fe0.2O3 has the highest acetic acid conversion (68.7%) and hydrogen yield (63.6%). Which is attributed to its more catalytic defect, stable structure and stronger basicity. Furthermore, to express more comprehensively on tar models, La0.8Ce0.2Ni0.8Fe0.2O3 were investigated with blends of acetic acid and acetone with different mole ratios (1:0, 4:1, 3:2, 2:3, 1:4 and 0:1) in temperature ranges (500 °C–900 °C), and weight hourly space velocity (WHSV = 12.02 h−1-15.63 h−1). The highest carbon conversion (85.7%) and hydrogen yield (88.5%) were obtained at 600 °C, mole ratio = 4:1, and WHSV = 14.43 h−1. It is noted that the result of the blend was better; however, based on in situ diffuse reflectance infrared fourier transform spectroscopy (in-situ DRIFTS) investigation, the enhancement ascribed to inhibition of ketonization reaction was occurred with pure acetic acid. In addition, high reaction temperature and weight hourly space velocity decrease the catalytic activity by accelerating sub-reaction and graphitization coke deposition. In a word, La0.8Ce0.2Ni0.8Fe0.2O3 catalyst shows good performance with hydrogen yield over 70% during 1440 min at optimum conditions.