Syngas production by dry reforming of methane using lyophilized nickel catalysts

Chemical Engineering Science 205 (2019) 74–82

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Syngas production by dry reforming of methane using lyophilized nickel catalysts Camilla Daniela Moura-Nickel a,⇑, Camila Gaspodini Tachinski a, Richard Landers b, Agenor De Noni Junior a, Elaine Virmond c, Michael Peterson d, Regina de Fátima Peralta Muniz Moreira a, Humberto Jorge José a a

Department of Chemical and Food Engineering, Federal University of Santa Catarina (UFSC), 88040-900 Florianópolis, Santa Catarina, Brazil Gleb Wataghin Institute of Physics, University of Campinas (UNICAMP), 13083-859 Campinas, São Paulo, Brazil Department of Energy and Sustainability, Federal University of Santa Catarina (UFSC), 88906-072 Araranguá, Santa Catarina, Brazil d Post-Graduate Program of Science and Materials Engineering, University of Extremo Sul Catarinense (UNESC), 88806-000 Criciúma, Santa Catarina, Brazil b c

h i g h l i g h t s
Epoxide-initiated gelation is an efficient method to produce lyophilized catalysts.
Lyophilization in the drying stage of the catalyst has proved to be satisfactory.
The LNi10 catalyst at 800 °C has presented the highest syngas production.
The CCom showed the highest carbon deposition at 600 °C.
The lyophilized nickel catalysts were more efficient than commercial catalyst.

a r t i c l e

i n f o

Article history: Received 17 October 2018 Received in revised form 30 March 2019 Accepted 20 April 2019 Available online 23 April 2019 Keywords: Hydrogen production CO2 utilization Coke Alumina Epoxide-initiated gelation method

a b s t r a c t In this work, lyophilized nickel catalysts were synthesized and compared with a commercial catalyst (CCom) in the process of dry reforming of methane. Ni-Al2O3 catalysts were prepared by epoxideinitiated gelation method and lyophilized with different percentage of active phase: 5 wt% (LNi5), 10 wt% (LNi10), 15 wt% (LNi15) and 20 wt% (LNi20). The catalysts were characterized by physical nitrogen adsorption, infrared spectroscopy, X-ray diffractometry, scanning electron microscopy and X-ray photoelectron spectroscopy. The catalytic tests were performed at 600 °C, 700 °C and 800 °C. All catalysts were active in the reforming reactions except the LNi5 and CCom catalysts at temperatures of 600 °C and 700 °C. The LNi10 catalyst at 800 °C has presented the highest syngas production. The CCom showed the highest carbon deposition at 600 °C with 2.26 mg which represents 4.52% of the initial weight of the catalyst. Increasing the nickel content from 5 wt% to 10 wt% resulted in a syngas gain of 1.31 lmol/min, 0.86 lmol/min and 1.25 lmol/min at 600 °C, 700 °C and 800 °C, respectively. The increase of the active phase from 10 wt% to 15 wt% and 20 wt% did not present significant effects in the syngas production. The lyophilization process in the drying stage of the catalyst has proved to be quite satisfactory in the dry reforming of methane. Ó 2019 Elsevier Ltd. All rights reserved.

1. Introduction Methane and carbon dioxide are the most abundant greenhouse gases and the main contributors to the recent climate-change issues (Aramouni et al., 2018; Noor et al., 2013). In order to reduce the amount of these gases in the atmosphere, extensive research has been conducted to find effective ways to convert CH4 and CO2 into other valuable products. The most interest option is the conversion of CO2 and CH4 to syngas (H2 and CO) owing to a low ⇑ Corresponding author. E-mail address: [email protected] (C.D. Moura-Nickel). https://doi.org/10.1016/j.ces.2019.04.035 0009-2509/Ó 2019 Elsevier Ltd. All rights reserved.

cost and relatively established technology (Bahari et al., 2016; De˛bek et al., 2017). Syngas is a chemical intermediate used for highly selective synthesis of different chemicals and oxygenated fuels, such as methanol and dimethyl ether, or Fischer-Tropsch reactions – for the production of liquid hydrocarbons such as gasoline, kerosene, and lubricants from petroleum (Alipour et al., 2014b; Danghyan et al., 2018; Park et al., 2014). Presently, syngas is commercially produced from steam reforming, partial oxidation and dry reforming of methane (Ayodele et al., 2016b). Academic researchers give direct attention towards Dry Reforming of Methane (DRM) due to its practical interests (Ayodele et al., 2016c,a; Ghelamallah and Granger, 2012) because it utilizes two

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greenhouse gases (Goula et al., 2015; Selvarajah et al., 2016). DRM produces a H2/CO ratio of unity which allows its application for the synthesis of oxygenated chemicals (Wurzel et al., 2000) and Fischer-Tropsch (Nieva et al., 2014). In addition, the DRM process is also cheaper than other methods since it eliminates the gas separation of products (San-José-Alonso et al., 2009). The DRM occurs when methane (CH4) reacts with carbon dioxide (CO2) producing carbon monoxide and hydrogen (1).

CH4 + CO2 ¡ 2CO + 2H2 DH = +247 kJ/mol

ð1Þ

This endothermic reaction requires high temperatures and, consequently, consumes high amounts of energy, even though operating at low pressures. In general, it occurs at temperatures ranging from 600 °C to 900 °C (Lau et al., 2011). The challenge in DRM process is to develop a catalyst that exhibits high activity and catalytic stability (Souza et al., 2004), besides being resistant to the deposition of carbon on the surface, avoiding its deactivation (Usman et al., 2015). In addition, these new catalysts need to be economically viable to be applied at industrial scale (Pompeo et al., 2007). Numerous studies have been published for the development of active and coke-resistant catalysts for the DRM reaction (AL-Fatesh et al., 2011; Alipour et al., 2014; Ayodele et al., 2016b, 2016a, 2016c; Bahari et al., 2016; Ghelamallah and Granger, 2012; Nieva et al., 2014; Park et al., 2014; Selvarajah et al., 2016; Wurzel et al., 2000). Most of the metals of the group VIII are known as catalysts of the DRM reaction (Nakamura et al., 1994; Wehinger et al., 2015). Moreover, noble metals such as ruthenium (Ru) and rhodium (Rh) are reported to be efficient in terms of activity and less sensitive to coke deposition compared to transition metals (Zhang et al., 2007). Despite this, the high cost of the noble metals limits their industrial application. Among all the transition metals, Ni-based catalysts and particularly nickel impregnated on alumina (Ni/Al2O3) have been recognized as the most effective in dry reforming of methane due to their low cost and high activity, although it suffers from carbon deposition (Aramouni et al., 2018; Gangadharan et al., 2012; Gurav et al., 2017; Muraleedharan Nair and Kaliaguine, 2016). The synthesis method of the catalyst has a direct effect on the catalytic performance and the physicochemical properties. The catalysts synthetized by sol-gel method present greater metal-support interaction, surface area, metal dispersion, and lesser carbonaceous deposition than those obtained using other synthesis methods (Bang et al., 2012; Yang et al., 2016). In the sol-gel preparation, the use of propylene oxide as a gelling agent has been shown to be a simple and efficient route (Bang et al., 2012; Moura-Nickel et al., 2019; Song et al., 2016; Yoo et al., 2015). The drying and calcination of catalyst are equally crucial in determining the final morphology, which is predominantly influenced by the preparation steps. Usually, the freeze drying improves the nanoparticle distribution over a support and maintains the high surface area and pore volume in a catalyst (Aw et al., 2014). Nevertheless, few studies have been reported to show the advantages of freeze drying (Carrier et al., 2003; Kim et al., 2009; Kraiwattanawong et al., 2011; Vergunst et al., 2001; Xi et al.,

2009; Yüksel Alpaydın et al., 2019). Recently, Cao (2017) compared the conventional oven drying and freeze drying on the performance of Ni/Al2O3 in DRM. The sublimation process in freeze drying increased the BET surface area but maintained small and uniform pore structure which protect NiO particle from aggregation. In this contribution, for first time, lyophilized catalysts containing different amounts of nickel were prepared by epoxide-initiated gelation method and applied in DRM. These catalysts were compared with a commercial catalyst and evaluated in terms of syngas production and coke deposition. 2. Material and methods 2.1. Synthesis of the lyophilized catalysts Catalysts with 5 wt% (LNi5), 10 wt% (LNi10), 15 wt% (LNi15) and 20 wt% (LNi20) of nickel were synthesized by the epoxide-initiated gelation method (Moura-Nickel et al., 2019). Nickel nitrate hexahydrate Ni(NO3)26H2O (Sigma Aldrich) was used as the nickel source of the active phase and aluminum nitrate nonahydrate Al(NO3)39H2O (Sigma Aldrich) was applied as support. A commercial reforming catalyst (CCom) with 10 wt% of nickel (given on a confidential basis) was also used in DRM to compare the catalytic performance with the lyophilized catalysts. The nickel and aluminum nitrate precursors were dissolved in ethanol CH3CH2OH (Neon) and stirred for 20 min at 500 rpm at room temperature until a homogeneous mixture was obtained. Propylene oxide C3H6O (Sigma Aldrich) was added as a gelling agent and after 6 min an opaque and green coloring gel was formed. The gel was matured at room temperature for 48 h to obtain a gel of uniform density. Subsequently, the gel was immersed in ethanol for 12 h. The solvent was changed and the gel was submerged for another 12 h in ethanol. The gel was then placed in the ultrafreezer (Liotop modelo UFR30) at  90 °C for 24 h and then lyophilized (Liotop modelo L101) for 24 h. The lyophilized nickel catalyst was calcined at 700 °C for 5 h at a heating rate of 10 °C∙min1. After synthesis, the catalyst was sieved (dp < 50 mm) and storage. 2.2. Characterization of the catalysts The catalysts were characterized by physical nitrogen adsorption, infrared spectroscopy (FTIR), X-ray diffractometry (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The physical adsorption of nitrogen was carried out in a Quantachrome equipment. The samples were submitted to 200 °C for 4 h to remove the water from the surface of the solid. The determination of the specific surface area was performed by the BET (Brunauer-Emmett-Teller) method, and the volume and pore diameter were determined by the BJH (Barret-Joyer-Halenda) adsorption method. Absorption spectra in the infrared region were obtained on a Fourier Transform Spectrophotometer (Shimadzu) using potassium

Table 1 Specific surface area (SBET), volume and pore diameter for LNi5, LNi10, LNi15, LNi20 and CCom catalysts. Catalyst

Ni (wt%)

SBET (m2g1)

Pore volume (cm3g1)

Average pore diameter (nm)

LNi5 LNi10 LNi15 LNi20 CCom

5 10 15 20 10

43 23 16 12 8

0.03530 0.00969 0.00982 0.00987 0.00436

3.29 1.66 2.44 2.96 2.15

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bromide (KBr) as the dispersing agent. The spectra were obtained in the region of 4000–400 cm1. The qualitative analysis of the crystalline phases was performed in a diffractometer (Shimadzu) using powder samples in the range of 2h between 10° to 80° with Cu-Ka radiation, wavelength k = 1.5420 Å with a scanning speed of 0.05°∙s1. The micrographs were obtained on a scanning electron microscope (Jeol). The samples were deposited to the stub with a double-faced carbon tape, covered with gold metallic ions, and then analyzed at acceleration voltage of 10 kV. XPS spectra were determined with an HA-100 spherical analyzer (VSW) and Al-Ka radiation (hv = 1486.6 eV) with 44 eV, which

produces a full width at half-maximum line width of 1.6 eV for the Au (4 f7/2) line. The samples were fixed to a stainless-steel holder with double-faced carbon tape. Charging effects were corrected so that the C 1s line had 284.6 eV. 2.3. Catalytic tests The catalytic activity of the lyophilized catalysts samples and the quantification of carbon deposit in DRM were evaluated in a differential reactor using Dyntherm-HP-ST high pressure thermobalance (Rubotherm). This thermobalance is consists of two modules: The Magnetic Suspension Balance (BSM) and the Gas

Fig. 1. N2 adsorption/desorption isotherms for lyophilized and commercial catalysts.

LNi5 600

LNi10

LNi5 Intensity (u.a.)

Transmittance (%)

LNi10 CCom

LNi15

400

LNi15

200

LNi20

LNi20

CCom 0

4000

3000

2000

1000 -1

Wavenumber (cm ) Fig. 2. Fourier transform infrared absorption spectra for LNi5, LNi10, LNi15, LNi20 and CCom catalysts.

10

20

30

40

50

60

70

80

2 Fig. 3. X-ray diffractograms for LNi5, LNi10, LNi15, LNi20 and CCom catalysts.

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Fig. 4. SEM images for LNi5, LNi10, LNi15, LNi20 and CCom catalysts.

Table 2 Catalytic performance using lyophilized and commercial catalysts in DRM. Catalyst

Temperature (°C)

H2/CO

H2 (mmol/min)

CO (mmol/min)

Coke (mg)

LNi5 LNi10 LNi15 LNi20 CCom

600 600 600 600 600

0.14 0.97 0.96 0.96 0.05

2.29E03 0.66 0.53 0.62 7.65E05

1.58E02 0.67 0.53 0.65 1.68E03

1.59 2.02 1.67 2.11 2.26

LNi5 LNi10 LNi15 LNi20 CCom

700 700 700 700 700

0.00 0.87 0.80 0.78 0.03

0.00 0.41 0.61 0.64 7.65E05

0.02 0.47 0.77 0.83 2.78E03

1.29 1.68 1.25 1.73 1.63

LNi5 LNi10 LNi15 LNi20 CCom

800 800 800 800 800

0.79 0.87 0.79 0.68 0.69

0.23 0.82 0.69 0.66 0.60

0.29 0.95 0.86 0.97 0.87

0.97 1.49 1.02 1.48 1.35

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Dosing System (SDG). As described in previous publications (Domenico et al., 2019; Moura-Nickel et al., 2019; Pacioni et al., 2016), the balance corrects the baseline and recalibrates during the procedure, ensuring highly accurate and stable weight measurements. The weight changes of the catalyst were measured at 10 s intervals with an accuracy of 10 lg. The use of a thermobalance enabled the measurement of the syngas production and the coke deposition in a single experimental procedure. Identification and quantification of the gas products formed during the dry reforming reaction were performed on a GC-TCD/ FID gas chromatograph with a coupled methanizer (MTN-1) (Shimadzu). For the dry reforming of methane, 50 mg of catalyst was used. The reaction temperatures studied were 600 °C, 700 °C and 800 °C, at atmospheric pressure with WHSV of 168,000 mL∙h1g1 cat. The weight hour space velocity value is higher than usually showed in literature to ensurance differential reactor conditions and that there is no external resistance to mass transfer (Fogler, 2016). The experimental procedure in thermobalance consisted in consecutive steps (Moura-Nickel et al., 2019). Initially, a purge was performed using argon at 300 mL∙min1 for 1 h at room temperature to remove residual gases present in the system. Then, each catalyst was activated using argon and hydrogen with a flow rate of 100 mL∙min1 and 25 mL∙min1, respectively, for 1 h with a heating rate of 20 °C∙min1 until the temperature reached 800 °C. The activation of the catalysts was ensured by measuring weight loss in the activation step until constant weight, in order to reduce the nickel oxide to the metallic form (Ni0). A purge with argon was performed again at 300 mL∙min1 for 20 min to withdraw the hydrogen gas present in the system during activation. In this step, was stabilized the reaction temperature. Then, the DRM reaction was performed using the argon, methane and carbon dioxide gases at flow rates of 100 mL∙min1, 20 mL∙min1 and 20 mL∙min1, respectively, for 5 h. Two more purges with argon occurred, of 30 min each, to clean the system and to cool it.

in the region of 3400–3600 cm1, which corresponds to the stretching and flexion vibrations of the OH groups of water on the alumina surface (Fig. 2). OH groups is related to coke removal capacity on the catalyst surface (Goula et al., 1996). It was observed that the band intensity increased with the nickel content in the catalyst. The commercial catalyst follows the same behavior, but with a deviation because of different composition and preparation method. 3.3. X-ray diffractograms The X-ray diffractograms for LNi5, LNi10, LNi15, LNi20 and CCom catalysts are presented in Fig. 3. The diffraction peaks at 38°, 46° and 67° refer to the NiAl2O4 nickel aluminate phase (Xu et al., 2001). These peaks are characteristic of c-alumina (Alipour et al., 2014b). The characteristic peaks of the NiO crystalline phase were not identified since the wide

2,5

Carbon Deposition (mg)

78

LNi5 LNi10 LNi15 LNi20 CCom

2,0

1,5

1,0

0,5 600

700

3. Results and discussion 3.1. Physical nitrogen adsorption

800

Temperature (°C) Fig. 5. Carbon deposition on LNi5, LNi10, LNi15, LNi20 and CCom catalysts after dry reforming of methane at temperatures of 600 °C, 700 °C and 800 °C.

The specific surface area (SBET), volume and pore diameter obtained for the lyophilized and commercial catalysts are presented in Table 1. Table 1 shows that the specific surface area values (SBET) of the lyophilized catalysts (LNi5, LNi10, LNi15 and LNi20) decreased as the metal content increased. This result suggests a coating of the support by the metal, which is also deposited inside the pores, blocking them and reducing the area of the catalyst. The adsorption/desorption isotherms in Fig. 1 demonstrates this behavior. According to the metal addition in the catalyst matrix, the mesopores are filled becoming micropores with reduction of the surface area. It was observed that the isotherm changes from the type IV (LNi5) to type I (Ni > 5 wt%). In addition, the commercial catalyst presented the smallest surface area (isotherm type II). The increase in the surface area is related to the preparation method, suggesting better catalytic performance using lyophilized nickel catalysts.

Fig. 6. Catalyst (A) before and (B) after the dry reforming of methane.

3.2. Infrared spectroscopy The Fourier transform infrared absorption spectra for LNi5, LNi10, LNi20 and CCom catalysts are shown in Fig. 2. The catalysts exhibited spectra in the 1385 cm1 band, corresponding to the formation of NiO, and a band in the region of 1600–1650 cm1, corresponding to OH bonds, which may be characteristic of Ni(OH)2 (Coates, 2006). In addition, it presented a band

Table 3 Elemental concentration (wt%) by XPS before and after DRM at 700 °C and 800 °C. Catalyst

LNi10

LNi10-700

LNi10-800

Ni O Al C

6.73 30.94 62.33 –

4.64 28.33 52.03 15.00

2.17 20.00 72.11 5.71

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peaks of c-Al2O3 may be superimposed on NiO peaks thus masking their presence, or else, the nickel content is below the detection limit of the equipment (Gill et al., 2010; Xu et al., 2001). It was observed too an increase in the intensity of the peaks due to the increase in the nickel content. The commercial catalyst showed low crystallinity. This behavior can be associated to the smaller particle size as well as smaller percentage in relation to the nominal value of Ni. Studies of the literature state that because of the proximity of the main peaks of the NiO and NiAl2O4, compounds with the cAl2O3 peaks, the identification of the phases becomes very difficult since displacements in the angular position of the diffraction peaks in function of the interaction between them and thus occur an

79

overlapping of the characteristic peaks (Moura-Nickel et al., 2019; Yoo et al., 2015).

3.4. Scanning electron microscopy Fig. 4 shows the electron microscopy images for lyophilized and CCom catalysts. The morphology of the lyophilized and commercial catalysts is of particles of several sizes and has no defined shape. In addition, the catalysts synthesized (LNi5, LNi10, LNi15 and LNi20) present more compact formats when compared to the commercial catalyst.

Fig. 7. XPS spectra for LNi10 before and after DRM at 700 °C (LNi10-700) and 800 °C (LNi10-800): (a) Ni 2p3/2, and (b) O 1s.

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LNi10 800

LNi10 700

Fig. 8. SEM images of spent LNi10 after DRM at 700 °C (LNi10-700) and 800 °C (LNi10-800).

3.5. Catalytic testing Table 2 presents the data obtained after 5 h of reaction for LNi5, LNi10, LNi15, LNi20 and CCom catalysts at temperatures of 600 °C, 700 °C and 800 °C. The LNi10 catalyst produced more syngas than the other catalysts (0.82 mmol/min H2 and 0.95 mmol/min CO) at 800 °C. Moreover, at temperatures of 600 °C, 700 °C and 800 °C the LNi10 catalyst showed the highest H2/CO ratio 0.97, 0.87 and 0.87 respectively. The catalyst with the lowest carbon deposition was LNi5 at 800 °C, with 0.97 mg, and was also the one that produced the lowest syngas concentration (0.23 mmol/min H2 and 0.29 mmol/min CO). Rathod and Bhale (2014) tested the catalyst content 10 wt% Ni/ Al2O3 (ball-shaped) in dry reforming of methane at temperatures of 550–700 °C, with CH4/CO2 = 1 ratio. The results showed that with temperature increase, there was an increase in the volume of syngas with reduction of CH4 and CO2, indicating an increase in the degree of conversion. The increase of the nickel content from 5 wt% to 10 wt% favored the dry reforming reaction with higher H2/CO ratio and higher amount of syngas produced (Table 2). However, it was observed that when the nickel content increased from 10 wt% to 15 wt% and 20 wt% the H2/CO ratio was lower than at 10 wt% nickel at all temperatures. Fig. 5 presents the carbon deposition at the end of the dry reforming of methane for LNi5, LNi10, LNi15, LNi20 and CCom catalysts at temperatures of 600 °C, 700 °C and 800 °C. The highest carbon formation, 2.26 mg (Fig. 5), occurred at 600 °C using CCom, corresponding to 4.52% of the initial weight of the catalyst. This can be explained thermodynamically by the Boudouard equation, in which carbon deposition is favored at low temperatures. Moreover, the presence of nickel species in the form of crystallites (NiO) favors the diffusion of carbon atoms by the presence of CO in the gas product. This diffusion occurs more easily in the presence of NiO because this species does not interact so strongly with the support, being the carbon atoms more easily distributed on the surface between the metal and support (Bradford and Vannice, 1996). Fig. 6 showed the catalyst before and after dry reforming of methane. Carbon deposition occurred in all reactions. 3.6. Characterization after DRM The XPS results for LNi10 catalyst before and after DRM at 700 °C (LNi10-700) and 800 °C (LNi10-800) are shown in Table 3 and Fig. 7. The highest carbon (C) concentration on the surface was found after reaction at 700 °C (Table 3), in agreement with the coke measured in the catalytic tests (Table 2 and Fig. 5). The XPS spectra are

similar for all samples (Fig. 7). The XPS spectra in the Ni2 p3/2 region (Fig. 7a) shows three peaks. The small first peak in the range of 853 eV could be ascribed to Ni2+ species in the form of free NiO (Charisiou et al., 2019). The second (large) peak for LNi10-800 (856.38), corresponding to Ni 2p3/2, was higher than the value for LNi10-700 (856.33 eV). A higher binding energy suggests a stronger interaction between the active phase and the support (Moura-Nickel et al., 2019; Wang et al., 2014). Furthermore, all catalysts showed a satellite peak (862 eV), that is typical for NiAl2O4 spinel (Xu et al., 2014), also detected from XRD results (Fig. 3). The O 1s region (Fig. 7b) showed characteristic peaks at 529.97– 531.01 eV ascribed to O2 in the lattice corresponding to AlAO and NiAO bonds, 531.57–532.49 eV corresponding to surface hydroxyl species and/or adsorbed oxygen (Charisiou et al., 2018; Wang et al., 2014). These results are in agreement with the FTIR spectra, as the same bonds were observed (Fig. 2). For the two peaks in the O 1s region, the binding energy decreased in the following order: LNi10> LNi10-800 > LNi10-700. The same behavior was observed in the Ni 2p3/2 region due coke deposition during DRM (Fig. 7a). These results are in agreement with those obtained in DRM (Table 2). Fig. 8 shows the SEM images of the spent LNi10. No significant differences occur after DRM at 700 °C and 800 °C. So, there was not changes in the catalyst morphology. The catalysts have been calcined at 700 °C and the reaction temperature were in the range of 600–800 °C, but the freeze drying has guaranteed the nickel distribution even after the DRM (Figs. 4 and 8). Low calcination temperatures could result in weak interaction between the active phase and support, and form agglomerates (Courson et al., 2002). However, freeze drying could overcome this agglomeration (Cao, 2017), how observed in Fig. 8.

4. Conclusions The lyophilization process in the drying stage of the catalyst has shown to be satisfactory in the dry reforming of methane. All catalysts were active and stable during the reaction of dry reforming, except for LNi5 and CCom at temperatures of 600 °C and 700 °C, which had H2/CO ratios close to zero. The highest carbon formation, 2.26 mg, representing 4.52% of the initial weight of the catalyst, occurred at the lowest temperature, 600 °C using CCom. The increase in nickel content from 5 wt% to 10 wt% resulted in a syngas gain of 1.31 lmol/min, 0.86 lmol/min and 1.25 lmol/min at 600 °C, 700 °C and 800 °C, respectively. The increase of the content of the active phase from 10 wt% to 15 wt% and 20 wt% did not present significant effects in syngas production. The LNi10 catalyst at 800 °C showed the highest syngas production while the LNi10 at 600 °C showed the highest H2/CO ratio, but produced 25% less syngas than LNi10 at 800 °C.

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Declaration of interest The authors declared that there is no conflict of interest. Acknowledgements The authors would like to thank the National Council for Scientific and Technological Development (CNPq/Brazil, Processes N°. 140698/2015-9 and N°. 153813/2018-0) and the Coordination for the Improvement of Higher Level Personnel (CAPES/Brazil) for their financial support. They also acknowledge the Central Laboratory of Electronic Microscopy (LCME-UFSC/Brazil) for technical support. References Al-Fatesh, A.S.A., Fakeeha, A.H., Abasaeed, A.E., 2011. Effects of selected promoters on Ni/Y-Al2O3 catalyst performance in methane dry reforming. Chinese J. Catal. 32, 1604–1609. https://doi.org/10.1016/S1872-2067(10)60267-7. Alipour, Z., Rezaei, M., Meshkani, F., 2014a. Effects of support modifiers on the catalytic performance of Ni/Al2O3 catalyst in CO2 reforming of methane. Fuel 129, 197–203. https://doi.org/10.1016/j.fuel.2014.03.045. Alipour, Z., Rezaei, M., Meshkani, F., 2014b. Effect of alkaline earth promoters (MgO, CaO, and BaO) on the activity and coke formation of Ni catalysts supported on nanocrystalline Al2O3 in dry reforming of methane. J. Ind. Eng. Chem. 20, 2858– 2863. https://doi.org/10.1016/j.jiec.2013.11.018. Aramouni, N.A.K., Touma, J.G., Tarboush, B.A., Zeaiter, J., Ahmad, M.N., 2018. Catalyst design for dry reforming of methane: analysis review. Renew. Sustain. Energy Rev. 82, 2570–2585. https://doi.org/10.1016/j.rser.2017.09.076. ˇ rnivec, I.G., Djinovic´, P., Pintar, A., 2014. Strategies to enhance Aw, M.S., Osojnik C dry reforming of methane: synthesis of ceria-zirconia/nickel–cobalt catalysts by freeze-drying and NO calcination. Int. J. Hydrogen Energy 39, 12636–12647. https://doi.org/10.1016/j.ijhydene.2014.06.083. Ayodele, B.V., Hossain, S.S., Lam, S.S., Osazuwa, O.U., Khan, M.R., Cheng, C.K., 2016a. Syngas production from CO2 reforming of methane over neodymium sesquioxide supported cobalt catalyst. J. Nat. Gas Sci. Eng. 34, 873–885. https://doi.org/10.1016/j.jngse.2016.07.059. Ayodele, B.V., Khan, M.R., Cheng, C.K., 2016b. Catalytic performance of ceriasupported cobalt catalyst for CO-rich hydrogen production from dry reforming of methane. Int. J. Hydrogen Energy 41, 198–207. https://doi.org/10.1016/j. ijhydene.2015.10.049. Ayodele, B.V., Khan, M.R., Lam, S.S., Cheng, C.K., 2016c. Production of CO-rich hydrogen from methane dry reforming over lanthania-supported cobalt catalyst: kinetic and mechanistic studies. Int. J. Hydrogen Energy 41, 4603– 4615. https://doi.org/10.1016/j.ijhydene.2016.01.091. Bahari, M.B., Phuc, N.H.H., Abdullah, B., Alenazey, F., Vo, D.-V.N., 2016. Ethanol dry reforming for syngas production over Ce-promoted Ni/Al2O3 catalyst. J. Environ. Chem. Eng. 4, 4830–4838. https://doi.org/10.1016/j.jece.2016.01.038. Bang, Y., Seo, J.G., Youn, M.H., Song, I.K., 2012. Hydrogen production by steam reforming of liquefied natural gas (LNG) over mesoporous Ni-Al2O3 aerogel catalyst prepared by a single-step epoxide-driven sol-gel method. Int. J. Hydrogen Energy 37, 1436–1443. https://doi.org/10.1016/j.ijhydene. 2011.10.008. Bradford, M.C.J., Vannice, M.A., 1996. Catalytic reforming of methane with carbon dioxide over nickel catalysts I. Catalyst characterization and activity. Appl. Catal. A Gen. 142, 73–96. https://doi.org/10.1016/0926-860X(96)00065-8. Cao, P., 2017. The Development of Ni Based Catalysts for Carbon Dioxide Reforming of Methane. University of Nottingham. Carrier, X., Lambert, J.-F., Kuba, S., Knözinger, H., Che, M., 2003. Influence of ageing on MoO3 formation in the preparation of alumina-supported Mo catalysts. J. Mol. Struct. 656, 231–238. https://doi.org/10.1016/S0022-2860(03)00328-4. Charisiou, N.D., Siakavelas, G., Tzounis, L., Sebastian, V., Monzon, A., Baker, M.A., Hinder, S.J., Polychronopoulou, K., Yentekakis, I.V., Goula, M.A., 2018. An in depth investigation of deactivation through carbon formation during the biogas dry reforming reaction for Ni supported on modified with CeO2 and La2O3 zirconia catalysts. Int. J. Hydrogen Energy 43, 18955–18976. https://doi.org/ 10.1016/j.ijhydene.2018.08.074. Charisiou, N.D., Tzounis, L., Sebastian, V., Hinder, S.J., Baker, M.A., Polychronopoulou, K., Goula, M.A., 2019. Investigating the correlation between deactivation and the carbon deposited on the surface of Ni/Al2O3 and Ni/La2O3-Al2O3 catalysts during the biogas reforming reaction. Appl. Surf. Sci. 474, 42–56. https://doi. org/10.1016/j.apsusc.2018.05.177. Coates, J., 2006. Interpretation of infrared spectra, a practical approach. In: Encyclopedia of Analytical Chemistry. John Wiley & Sons, Ltd, Chichester, UK. https://doi.org/10.1002/9780470027318.a5606. Courson, C., Udron, L., S´wierczyn´ski, D., Petit, C., Kiennemann, A., 2002. Hydrogen production from biomass gasification on nickel catalysts: tests for dry reforming of methane. Catal. Today 76, 75–86. https://doi.org/10.1016/S09205861(02)00202-X. Danghyan, V., Calderon Novoa, S., Mukasyan, A., Wolf, E.E., 2018. Pressure dilution, a new method to prepare a stable Ni/fumed silica catalyst for the dry reforming of

81

methane. Appl. Catal. B Environ. 234, 178–186. https://doi.org/10.1016/j. apcatb.2018.04.033. De˛bek, R., Motak, M., Grzybek, T., Galvez, M., Da Costa, P., 2017. A Short review on the catalytic activity of hydrotalcite-derived materials for dry reforming of methane. Catalysts 7, 32. https://doi.org/10.3390/catal7010032. Domenico, M.D., Amorim, S.M., Collazzo, G.C., José, H.J., Moreira, R.F.P.M., 2019. Coal gasification in the presence of lithium orthosilicate. Part 1: Reaction kinetics. Chem. Eng. Res. Des. 141, 529–539. https://doi.org/10.1016/j. cherd.2018.11.011. Fogler, H.S. (Ed.), 2016. Elements of Chemical Reaction Engineering. fifth ed. Pearson Education (US), Upper Saddle River. Gangadharan, P., Kanchi, K.C., Lou, H.H., 2012. Evaluation of the economic and environmental impact of combining dry reforming with steam reforming of methane. Chem. Eng. Res. Des. 90, 1956–1968. https://doi.org/10.1016/j. cherd.2012.04.008. Ghelamallah, M., Granger, P., 2012. Impact of barium and lanthanum incorporation to supported Pt and Rh on a-Al2O3 in the dry reforming of methane. Fuel 97, 269–276. https://doi.org/10.1016/j.fuel.2012.02.068. Gill, S.K., Brown, P., Ogundiya, M.T., Hope-Weeks, L.J., 2010. High surface area alumina-supported nickel (II) oxide aerogels using epoxide addition method. J. Sol-Gel Sci. Technol. 53, 635–640. https://doi.org/10.1007/s10971-009-2142-8. Goula, M., Lemonidou, A., Efstathiou, A., 1996. Characterization of carbonaceous species formed during reforming of CH4 with CO2 over Ni/CaO–Al2O3 catalysts studied by various transient techniques. J. Catal. 161, 626–640. https://doi.org/ 10.1006/jcat.1996.0225. Goula, M.A., Charisiou, N.D., Papageridis, K.N., Delimitis, A., Pachatouridou, E., Iliopoulou, E.F., 2015. Nickel on alumina catalysts for the production of hydrogen rich mixtures via the biogas dry reforming reaction: influence of the synthesis method. Int. J. Hydrogen Energy 40, 9183–9200. https://doi.org/ 10.1016/j.ijhydene.2015.05.129. Gurav, H.R., Dama, S., Samuel, V., Chilukuri, S., 2017. Influence of preparation method on activity and stability of Ni catalysts supported on Gd doped ceria in dry reforming of methane. J. CO2 Util. 20, 357–367. https://doi.org/10.1016/j. jcou.2017.06.014. Kim, H.J., Choi, S.M., Nam, S.H., Seo, M.H., Kim, W.B., 2009. Effect of Rh content on carbon-supported PtRh catalysts for dehydrogenative electrooxidation of cyclohexane to benzene over polymer electrolyte membrane fuel cell. Appl. Catal. A Gen. 352, 145–151. https://doi.org/10.1016/j.apcata.2008.10.014. Kraiwattanawong, K., Sano, N., Tamon, H., 2011. Low-cost production of mesoporous carbon/carbon composite cryogels. Carbon N. Y. 49, 3404–3411. https://doi.org/10.1016/j.carbon.2011.04.018. Lau, C.S., Tsolakis, A., Wyszynski, M.L., 2011. Biogas upgrade to syn-gas (H2–CO) via dry and oxidative reforming. Int. J. Hydrogen Energy 36, 397–404. https://doi. org/10.1016/j.ijhydene.2010.09.086. Moura-Nickel, C.D., Costa, R.L., Salvador Ferreira, S.R., de Fátima Peralta Muniz Moreira, R., José, H.J., 2019. Ni Y2O3Al2O3 aerogel catalysts with high coke deposition resistance for syngas production by biogas reforming. Int. J. Hydrogen Energy. https://doi.org/10.1016/j.ijhydene.2019.03.022. Muraleedharan Nair, M., Kaliaguine, S., 2016. Structured catalysts for dry reforming of methane. New J. Chem. 40, 4049–4060. https://doi.org/10.1039/C5NJ03268G. Nakamura, J., Aikawa, K., Sato, K., Uchijima, T., 1994. Role of support in reforming of CH4 with CO2 over Rh catalysts. Catal. Lett. 25, 265–270. https://doi.org/ 10.1007/BF00816306. Nieva, M.A., Villaverde, M.M., Monzón, A., Garetto, T.F., Marchi, A.J., 2014. Steammethane reforming at low temperature on nickel-based catalysts. Chem. Eng. J. 235, 158–166. https://doi.org/10.1016/j.cej.2013.09.030. Noor, Z.Z., Yusuf, R.O., Abba, A.H., Abu Hassan, M.A., Mohd Din, M.F., 2013. An overview for energy recovery from municipal solid wastes (MSW) in Malaysia scenario. Renew. Sustain. Energy Rev. 20, 378–384. https://doi.org/10.1016/j. rser.2012.11.050. Pacioni, T.R., Soares, D., Domenico, M. Di, Rosa, M.F., de Moreira, R., José H.J., F.P.M., 2016. Bio-syngas production from agro-industrial biomass residues by steam gasification. Waste Manag. 58, 221–229. https://doi.org/10.1016/j. wasman.2016.08.021. Park, N., Park, M.-J., Baek, S.-C., Ha, K.-S., Lee, Y.-J., Kwak, G., Park, H.-G., Jun, K.-W., 2014. Modeling and optimization of the mixed reforming of methane: maximizing CO2 utilization for non-equilibrated reaction. Fuel 115, 357–365. https://doi.org/10.1016/j.fuel.2013.07.035. Pompeo, F., Nichio, N.N., Souza, M.M.V.M., Cesar, D.V., Ferretti, O.A., Schmal, M., 2007. Study of Ni and Pt catalysts supported on a-Al2O3 and ZrO2 applied in methane reforming with CO2. Appl. Catal. A Gen. 316, 175–183. https://doi.org/ 10.1016/j.apcata.2006.09.007. Rathod, V., Bhale, P.V., 2014. Experimental investigation on biogas reforming for syngas production over an alumina based nickel catalyst. Energy Proc. 54, 236– 245. https://doi.org/10.1016/j.egypro.2014.07.267. San-José-Alonso, D., Juan-Juan, J., Illán-Gómez, M.J., Román-Martínez, M.C., 2009. Ni, Co and bimetallic Ni–Co catalysts for the dry reforming of methane. Appl. Catal. A Gen. 371, 54–59. https://doi.org/10.1016/j.apcata.2009.09.026. Selvarajah, K., Phuc, N.H.H., Abdullah, B., Alenazey, F., Vo, D.-V.N., 2016. Syngas production from methane dry reforming over Ni/Al2O3 catalyst. Res. Chem. Intermed. 42, 269–288. https://doi.org/10.1007/s11164-015-2395-5. Song, J.H., Han, S.J., Yoo, J., Park, S., Kim, D.H., Song, I.K., 2016. Hydrogen production by steam reforming of ethanol over Ni-Sr-Al2O3-ZrO2 aerogel catalyst. J. Mol. Catal. A Chem. 424, 342–350. https://doi.org/10.1016/ j.molcata.2016.09.013.

82

C.D. Moura-Nickel et al. / Chemical Engineering Science 205 (2019) 74–82

Souza, M. de M.V., Clavé, L., Dubois, V., Perez, C.A., Schmal, M., 2004. Activation of supported nickel catalysts for carbon dioxide reforming of methane. Appl. Catal. A Gen. 272, 133–139. https://doi.org/10.1016/j.apcata.2004.05.026. Usman, M., Wan Daud, W.M.A., Abbas, H.F., 2015. Dry reforming of methane: influence of process parameters—a review. Renew. Sustain. Energy Rev. 45, 710–744. https://doi.org/10.1016/j.rser.2015.02.026. Vergunst, T., Kapteijn, F., Moulijn, J.A., 2001. Monolithic catalysts—non-uniform active phase distribution by impregnation. Appl. Catal. A Gen. 213, 179–187. https://doi.org/10.1016/S0926-860X(00)00896-6. Wang, Y., Wang, L., Gan, N., Lim, Z.-Y., Wu, C., Peng, J., Wang, W.G., 2014. Evaluation of Ni/Y2O3/Al2O3 catalysts for hydrogen production by autothermal reforming of methane. Int. J. Hydrogen Energy 39, 10971–10979. https://doi.org/10.1016/j. ijhydene.2014.05.074. Wehinger, G.D., Eppinger, T., Kraume, M., 2015. Detailed numerical simulations of catalytic fixed-bed reactors: heterogeneous dry reforming of methane. Chem. Eng. Sci. 122, 197–209. https://doi.org/10.1016/j.ces.2014.09.007. Wurzel, T., Malcus, S., Mleczko, L., 2000. Reaction engineering investigations of CO2 reforming in a fluidized-bed reactor. Chem. Eng. Sci. 55, 3955–3966. https://doi. org/10.1016/S0009-2509(99)00444-3. Xi, X., Nie, Z., Jiang, Y., Xu, X., Zuo, T., 2009. Preparation and characterization of ultrafine cobalt powders and supported cobalt catalysts by freeze-drying. Powder Technol. 191, 107–110. https://doi.org/10.1016/j.powtec.2008.09.017.

Xu, L., Miao, Z., Song, H., Chou, L., 2014. CO2 reforming of CH4 over rare earth elements functionalized mesoporous Ni–Ln (Ln = Ce, La, Sm, Pr)–Al–O composite oxides. Int. J. Hydrogen Energy 39, 3253–3268. https://doi.org/ 10.1016/j.ijhydene.2013.12.077. Xu, Z., Li, Y., Zhang, J., Chang, L., Zhou, R., Duan, Z., 2001. Bound-state Ni species—a superior form in Ni-based catalyst for CH4/CO2 reforming. Appl. Catal. A Gen. 210, 45–53. https://doi.org/10.1016/S0926-860X(00)00798-5. Yang, T., Chen, W., Chen, L., Liu, W., Zhang, D., 2016. Promotion effect between Ni and Co aerogel catalysts in CH4 reforming with CO2 and O2. J. CO2 Util. 16, 130–137. https://doi.org/10.1016/j.jcou.2016.07.005. Yoo, J., Bang, Y., Han, S.J., Park, S., Song, J.H., Song, I.K., 2015. Hydrogen production by tri-reforming of methane over nickel–alumina aerogel catalyst. J. Mol. Catal. A Chem. 410, 74–80. https://doi.org/10.1016/j.molcata.2015.09.008. Yüksel Alpaydın, C., Gülbay, S.K., Ozgur Colpan, C., 2019. A review on the catalysts used for hydrogen production from ammonia borane. Int. J. Hydrogen Energy. https://doi.org/10.1016/j.ijhydene.2019.02.181. Zhang, J., Wang, H., Dalai, A., 2007. Development of stable bimetallic catalysts for carbon dioxide reforming of methane. J. Catal. 249, 300–310. https://doi.org/ 10.1016/j.jcat.2007.05.004.