Superior performance of freeze-dried Ni/ZnO-Al₂O₃ adsorbent in the ultra-deep desulfurization of high sulfur model gasoline

TY - JOUR

T1 - Superior performance of freeze-dried Ni/ZnO-Al2O3 adsorbent in the ultra-deep desulfurization of high sulfur model gasoline

AU - Ullah, Rooh

AU - Bai, Peng

AU - Wu, Pingping

AU - Etim, U. J.

AU - Zhang, Zhanquan

AU - Han, Dezhi

AU - Subhan, Fazle

AU - Ullah, Saif

AU - Rood, Mark J.

AU - Yan, Zifeng

N1 - Publisher Copyright: © 2016 Elsevier B.V.

PY - 2017/2/1

Y1 - 2017/2/1

N2 - Reactive adsorption desulfurization (RADS) is an effective approach to the ultra-deep desulfurization under mild conditions. The sulfur adsorption capacity of the adsorbents strongly depends on the pore structure, the chemical states and the dispersion of active species. In this work, ZnO-Al2O3 mixed oxides with an improved structure were synthesized via a freeze-drying modified cation-anion double hydrolysis (CADH) technique and used as the support. The fresh and spent catalysts were characterized through N2 adsorption-desorption, H2-temperature programmed reduction, X-ray diffraction, UV–vis diffuse reflection spectroscopy, Fourier transformed infrared spectroscopy and transmission electron microscopy (TEM). Freeze drying technique provided the adsorbent with a smaller sized ZnO and an improved pore structure compared with the normal oven drying method. Evaluation results in the RADS of a high sulfur model gasoline reveals that the freeze-dried Ni/ZnO-Al2O3 (40 °C) with a crystallization temperature of 40 °C exhibits a superior RADS performance with an accumulative sulfur adsorption capacity of 90 mg S/g, which is 5.3% and 118% higher than those of adsorbents prepared by the normal oven drying and the conventional kneading methods. A high amount of small ZnO particles, improved textural properties and the absence of inactive NiAl2O4 phase are among the factors accounting for the superior RADS performance of Ni/ZnO-Al2O3 adsorbent prepared by the freeze-drying method. Upon four RADS-regeneration cycles, sample Ni/ZnO-Al2O3 (40°C) exhibited a high stability without evident activity loss.

AB - Reactive adsorption desulfurization (RADS) is an effective approach to the ultra-deep desulfurization under mild conditions. The sulfur adsorption capacity of the adsorbents strongly depends on the pore structure, the chemical states and the dispersion of active species. In this work, ZnO-Al2O3 mixed oxides with an improved structure were synthesized via a freeze-drying modified cation-anion double hydrolysis (CADH) technique and used as the support. The fresh and spent catalysts were characterized through N2 adsorption-desorption, H2-temperature programmed reduction, X-ray diffraction, UV–vis diffuse reflection spectroscopy, Fourier transformed infrared spectroscopy and transmission electron microscopy (TEM). Freeze drying technique provided the adsorbent with a smaller sized ZnO and an improved pore structure compared with the normal oven drying method. Evaluation results in the RADS of a high sulfur model gasoline reveals that the freeze-dried Ni/ZnO-Al2O3 (40 °C) with a crystallization temperature of 40 °C exhibits a superior RADS performance with an accumulative sulfur adsorption capacity of 90 mg S/g, which is 5.3% and 118% higher than those of adsorbents prepared by the normal oven drying and the conventional kneading methods. A high amount of small ZnO particles, improved textural properties and the absence of inactive NiAl2O4 phase are among the factors accounting for the superior RADS performance of Ni/ZnO-Al2O3 adsorbent prepared by the freeze-drying method. Upon four RADS-regeneration cycles, sample Ni/ZnO-Al2O3 (40°C) exhibited a high stability without evident activity loss.

KW - Freeze drying

KW - Mixed oxide

KW - NiO

KW - Reactive adsorption desulfurization

KW - Thiophene

KW - ZnO

UR - http://www.scopus.com/inward/record.url?scp=84999828419&partnerID=8YFLogxK

U2 - 10.1016/j.fuproc.2016.10.022

DO - 10.1016/j.fuproc.2016.10.022

M3 - 文章

AN - SCOPUS:84999828419

SN - 0378-3820

VL - 156

SP - 505

EP - 514

JO - Fuel Processing Technology

JF - Fuel Processing Technology

ER -