Synthesis and characterization of cerium promoted Ni/SBA-16 oxygen carrier in cyclic chemical looping steam methane reforming

Meshksar, Maryam; Daneshmand-Jahromi, Sanaz; Rahimpour, Mohammad Reza

doi:10.1016/j.jtice.2017.04.012

Cited by 51 publications

(21 citation statements)

References 45 publications

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“…The improvement of methane conversion with Ni loading percentage could be due to the more available lattice oxygen by increasing the NiO molecules. Afterwards the reduction in the activity is related to the agglomeration tendency of nickel particles at higher Ni weight percentage [48]. It can be concluded from Figure 9 that at higher reduction temperature the difference between catalytic activity and hydrogen production yield of xNi-2.…”

Section: Effect Of Ni Loading Percentage and Temperature On The Catalmentioning

confidence: 86%

“…Another popular strategy in order to avoid carbon formation and/or stabilizing Ni nanoparticles in the channels of two dimensional mesoporous silica is the utilization of promotional oxides such as Ce 2 O 3 , La 2 O 3 , CaO, MgO and Y 2 O 3 [44][45][46][47][48]. Li et al [46] prepared Ce promoted Ni/SiO 2 catalyst using co-impregnation method and applied for producing syngas in the combined partial oxidation of methane with CO 2 reforming.…”

Section: Introductionmentioning

confidence: 99%

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Hydrogen Production from Cyclic Chemical Looping Steam Methane Reforming over Yttrium Promoted Ni/SBA-16 Oxygen Carrier

et al. 2017

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Abstract:In this work, the modification of Ni/SBA-16 oxygen carrier (OC) with yttrium promoter is investigated. The yttrium promoted Ni-based oxygen carrier was synthesized via co-impregnation method and applied in chemical looping steam methane reforming (CL-SMR) process, which is used for the production of clean energy carrier. The reaction temperature (500-750 • C), Y loading (2.5-7.4 wt. %), steam/carbon molar ratio (1-5), Ni loading (10-30 wt. %) and life time of OCs over 16 cycles at 650 • C were studied to investigate and optimize the structure of OC and process temperature with maximizing average methane conversion and hydrogen production yield. The synthesized OCs were characterized by multiples techniques. The results of X-ray powder diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) of reacted OCs showed that the presence of Y particles on the surface of OCs reduces the coke formation. The smaller NiO species were found for the yttrium promoted OC and therefore the distribution of Ni particles was improved. The reduction-oxidation (redox) results revealed that 25Ni-2.5Y/SBA-16 OC has the highest catalytic activity of about 99.83% average CH 4 conversion and 85.34% H 2 production yield at reduction temperature of 650 • C with the steam to carbon molar ratio of 2.

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Section: Effect Of Ni Loading Percentage and Temperature On The Catalmentioning

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Hydrogen Production from Cyclic Chemical Looping Steam Methane Reforming over Yttrium Promoted Ni/SBA-16 Oxygen Carrier

et al. 2017

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“…The reason is that, during first cycles, not all of the nickel particles burn into oxygen to form nickel oxides and by further reduction process, suitable oxidize phases were formed. But, for 15Ni/Ce-SBA-16(∞) OC, methane conversion and hydrogen yield first increase to reach 99.9% and 84.3%, respectively, during four cycles, and then they decrease through three next cycles, but after that, no further reduction was detected, as exhibited in Figure 9a,b, coke formation on the surface of OC causes this reduction of activity [41]. The structural change (BET surface area, pore volume, and pore size) of optimized oxygen carrier after 16 redox cycles is presented in Table 2.…”

Section: Time-on-stream Behavior Of Oxygen Carriermentioning

confidence: 91%

“…As can be seen in Figure 7a, the methane conversion was increased by raising temperature from 500 to 750 • C due to endothermic nature of steam methane reforming [40][41][42]. In addition, the oxygen transform rate of Ni-based oxygen carrier is improved at elevated temperatures.…”

Section: Effect Od Si To Ce Molar Ratios On the Activitymentioning

confidence: 99%

Synthesis and Application of Cerium-Incorporated SBA-16 Supported Ni-Based Oxygen Carrier in Cyclic Chemical Looping Steam Methane Reforming

et al. 2018

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Hydrogen, as a clean energy carrier, could be produced aided by cyclic oxidation-reduction of oxygen carriers (OCs) in contact with carbonaceous fuel in chemical looping steam methane reforming (CL-SMR) process. In this study, the cerium was incorporated into the SBA-16 support structure to synthesize the Ni/Ce-SBA-16 OC. The supports were synthesized using hydrothermal method followed by impregnation of Ni and characterized via low and wide angle X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), coupled with energy dispersive X-ray (EDX) spectroscopy, and transmission electron micrograph (TEM) techniques. In addition, the effect of various Si/Ce molar ratios (20-60) in the support structure, Ni loading (10-30 wt %), reaction temperature (500-750 • C), and life time of optimal oxygen carrier over 16 cycles were investigated. The results of wide angle XRD and SEM revealed that the incorporation of CeO 2 in the channels of SBA-16 caused the formation of nickel metallic particles with smaller size and prevents the coke formation. The results showed that OC with 15 wt % Ni and Si/Ce molar ratio of 40 (15Ni/Ce-SBA-16(40)) has the best performance when compared with other OCs in terms of catalytic activity and structural properties. The methane conversion of about 99.7% was achieved at 700 • C using 15Ni/Ce-SBA-16(40) OC. We anticipate that the strategy can be extended to investigate a variety of novel modified mesoporous silica as the supporting material for the Ni based OCs.

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“…The required oxygen carrier should be able to undergo repeated redox cycles. Furthermore, some important screening criteria such as high methane conversion, low cost, an acceptable oxygen transfer capacity, attrition and agglomeration resistance, non-toxicity and sufficient reversibility should be considered for a correct choice [36,37]. Some possible transition metals including active oxides of nickel, copper, cobalt, iron and manganese, possess greatly conditions mentioned above [36,38].…”

Section: Introductionmentioning

confidence: 99%

Promotion of Ca-Co Bifunctional Catalyst/Sorbent with Yttrium for Hydrogen Production in Modified Chemical Looping Steam Methane Reforming Process

et al. 2017

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Abstract:In this study, the application of a calcium-based bifunctional catalyst/sorbent is investigated in modified chemical looping steam methane reforming (CLSMR) process for in situ CO 2 sorption and H 2 production. The yttrium promoted Ca-Co samples were synthesized and applied as bifunctional catalysts/sorbent. The influence of reduction temperature (500-750 • C), Ca/Co and Ca/Y ratios (1.5-∞ and 3-18, respectively) and catalyst life time are determined in CLSMR process. The physicochemical transformation of fresh, used and regenerated samples after 16 redox cycles are determined using X-ray powder diffraction (XRD), N 2 adsorption-desorption, field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM) techniques. The effect of yttrium promoter on the structure of catalyst and regeneration step on the reversibility of bifunctional catalyst/sorbent was two important factors. The characterization results revealed that the presence of yttrium in the structure of Ca-9Co sample could improve the morphology and textural properties of catalyst/sorbents. The suitable reversibility of bifunctional catalyst/sorbents during the repeated cycles is confirmed by characterization of calcined samples. The Ca-9Co-4.5Y as optimal catalyst illustrated superior performance and stability. It showed about 95.8% methane conversion and 82.9% hydrogen yield at 700 • C and stable activity during 16 redox cycles.

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Synthesis and characterization of cerium promoted Ni/SBA-16 oxygen carrier in cyclic chemical looping steam methane reforming

Cited by 51 publications

References 45 publications

Hydrogen Production from Cyclic Chemical Looping Steam Methane Reforming over Yttrium Promoted Ni/SBA-16 Oxygen Carrier

Hydrogen Production from Cyclic Chemical Looping Steam Methane Reforming over Yttrium Promoted Ni/SBA-16 Oxygen Carrier

Synthesis and Application of Cerium-Incorporated SBA-16 Supported Ni-Based Oxygen Carrier in Cyclic Chemical Looping Steam Methane Reforming

Promotion of Ca-Co Bifunctional Catalyst/Sorbent with Yttrium for Hydrogen Production in Modified Chemical Looping Steam Methane Reforming Process

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