Oxy-steam Reforming Research Articles

Sustainable syngas production by oxy-steam reforming of simulated biogas over NiCe/MgAl hydrotalcite-derived catalysts: Role of support preparation methods on activity

Herein, a series of hydrotalcite-derived MgAl supports were prepared by co-precipitation and hydrothermal methods. NiCe/MgAl catalysts were prepared by loading Ni (10 wt%) and Ce (2.5 wt%) on supports using sequential incipient wetness impregnation and tested in oxy-steam reforming of simulated biogas to produce syngas. N2-physisorption, XRD, XPS, SEM, TEM, ICP-OES, TGA, and Raman were used for catalyst characterization. Reactivity was evaluated at 600 °C, 700 °C, and 800 °C with a constant GHSV (45,000 ml gcat−1 h−1) and feed ratio (CH4/CO2/O2/H2O = 1/0.67/0.1/0.3). The results demonstrate that increasing the co-precipitation aging temperature and the hydrothermal reaction temperature affected the surface area, pore volume, and Ni crystallite size. However, no significant change in reactivity was observed. The NiCe/MgAl catalyst with co-precipitation aging temperature of 140 °C (NCMA140-Co) exhibited lower carbon deposition probably due to higher Ce4+ concentration. Therefore, NCMA140-Co provided high stability and conversions of CH4 (94%) and CO2 (82%) with H2/CO ratio (1.6) at 800 °C without carbon deposition.

Fourier transform infrared spectroscopic studies of methane and liquefied natural gas reforming processes on Ni/CeO2 catalyst

For the first time, a mechanistic study of methane oxy-steam reforming and LNG (OSR-LNG) processes is presented using Fourier transform infrared (FTIR) spectroscopy. The FTIR measurements were carried out in the temperature range of 200–600 °C in the tested processes. The reaction mechanisms of oxy-steam reforming of CH4 or LNG were proposed from the results obtained. It was found that the dissociation of methane into carbon-containing molecules and/or into carbon molecules adsorbed on the catalyst surface is a crucial step in determining the reaction rate. The results can be used to design catalytic systems for natural gas reforming.

Influence of silica promotion on NiCe/MgAlSi catalysts for the oxy-steam reforming of biogas to syngas

This work has exploited the effects of silica on magnesium aluminum silicate supported NiCe based catalysts (NiCe/MgAlSi) prepared using sol-gel method followed by incipient wetness impregnation for syngas production through oxy-steam reforming (OSR) of biogas. Measurements investigating the effects of increasing Si/Al molar ratio (0–5) on activity and carbon deposition were performed in a once-through flow reactor at atmospheric pressure and temperatures of 600, 700, and 800 °C with a fixed GHSV of 45,000 ml gcat−1 h−1 and molar feed ratio of CH4/CO2/O2/H2O = 1/0.67/0.1/0.3. The catalysts were characterized by N2-physisorption, XRD, SEM, HRTEM, TGA, Raman, and ICP-OES. In the results, the addition of silica has been found to increase Ni crystallite sizes and decrease carbon deposition. Thus, NiCe/MgAlSi with Si/Al = 5 is promising, exhibiting high conversions of CH4 (91.7%), CO2 (80.4%), and H2/CO ratio of 1.6 without carbon deposition and good stability for 120 h at 800 °C.

Oxy-Steam Reforming of Liquefied Natural Gas (LNG) on Mono- and Bimetallic (Ag, Pt, Pd or Ru)/Ni Catalysts

This work presents, for the first time, the comparative physicochemical and reactivity studies of a range of bimetallic Pt-Ni, Pd-Ni, Ru-Ni, and Ag-Ni catalysts in the oxy-steam reforming (OSR) of liquefied natural gas (LNG) reaction towards hydrogen generation. In order to achieve the intended purpose of this work, a binary oxide CeO2·ZrO2 (1:2) support was prepared via a co-precipitation method. The catalysts’ physicochemical properties were studied using X-ray diffraction (XRD), BET, TPR-H2, TPD-NH3, SEM-EDS and XPS methods. The highest activity in the studied process was exhibited by the 1%Pt-5%Ni catalyst supported on CeO2·ZrO2 (1:2) system. The highest activity of this system is explained by the specific interactions occurring between the components of the active phase and between the components of the active phase and the carrier itself. The activity results showed that this catalytic system exhibited above 71% of the methane conversion at 600 °C and 60% yield of hydrogen formation. The results of this work demonstrate that the Pt-Ni and Ru-Ni catalytic systems hold promise to be applied in the production of hydrogen to power solid oxide fuel cells.

Influence of NiO/La2O3 Catalyst Preparation Method on Its Reactivity in the Oxy-Steam Reforming of LNG Process

The oxy-steam reforming of liquefied natural gas reaction (OSR-LNG) is promising process for syngas generation. In this paper, the catalytic properties of NiO/La2O3 systems prepared by wet impregnation and co-precipitation methods were extensively investigated in OSR-LNG reaction. The physicochemical properties of the studied catalytic materials were determined using various techniques including Temperature programmed reduction (TPR-H2), Temperature programmed desorption (TPD-NH3), Brunauer, Emmett and Teller (BET), X-ray diffraction (XRD) and Scanning electron microscopy (SEM) with an energy dispersive X-Ray spectrometer (EDS). Reactivity measurements performed in the OSR-LNG process showed that the catalyst preparation method and the calcination temperature significantly affected the activity of NiO/La2O3 catalysts in the OSR-LNG reaction. The catalytic activity tests showed that NiO/La2O3 system prepared by a wet impregnation method and calcined at 700 °C showed the total conversion of the LNG component at 900 °C and the highest H2 yield at 700 and 900 °C. The phase composition studies confirmed the formation of the LaNiO3 structure in the case of the NiO/La2O3 catalyst prepared by wet impregnation, calcined at the temperature of 700 °C. Catalytic activity measurements showed that the reactivity of the catalysts was related to their phase composition and acidity. SEM images of spent catalysts showed that the smallest amount of carbon deposit was detected on the surface of the most active systems.

The Effect of Modifiers on the Performance of Ni/CeO2 and Ni/La2O3 Catalysts in the Oxy-Steam Reforming of LNG.

This work interrogates for the first time the catalytic properties of various monometallic Ni catalysts in the oxy-steam reforming of LNG. Various research techniques, including X-ray diffraction (XRD), specific surface area and porosity analysis (BET method), scanning electron microscopy with X-ray microanalysis (SEM-EDS), temperature-programmed desorption of ammonia (TPD-NH3), temperature-programmed reduction (TPR-H2) and the FTIR method, were used to study their physicochemical properties. The mechanism of the oxy-steam reforming of LNG is also discussed in this paper. The high activity of monometallic catalysts supported on 5% La2O3–CeO2 and 5% ZrO2–CeO2 oxides in the studied process have been proven and explained on the basis of their acidity, specific surface area, sorption properties in relation to the reaction products, the crystallite size of the metallic nickel and their phase composition.

Catalysts for Hydrogen Generation via Oxy-Steam Reforming of Methanol Process.

The production of pure hydrogen is one of the most important problems of the modern chemical industry. While high volume production of hydrogen is well under control, finding a cheap method of hydrogen production for small, mobile, or his receivers, such as fuel cells or hybrid cars, is still a problem. Potentially, a promising method for the generation of hydrogen can be oxy–steam-reforming of methanol process. It is a process that takes place at relatively low temperature and atmospheric pressure, which makes it possible to generate hydrogen directly where it is needed. It is a process that takes place at relatively low temperature and atmospheric pressure, which makes it possible to generate hydrogen directly where it is needed. This paper summarizes the current state of knowledge on the catalysts used for the production of hydrogen in the process of the oxy–steam-reforming of methanol (OSRM). The development of innovative energy generation technologies has intensified research related to the design of new catalysts that can be used in methanol-reforming reactions. This review shows the different pathways of the methanol-reforming reaction. The paper presents a comparison of commonly used copper-based catalysts with other catalytic systems for the production of H2 via OSRM reaction. The surface mechanism of the oxy–steam-reforming of methanol and the kinetic model of the OSRM process are discussed.

Oxy-Steam Reforming of Natural Gas on Ni Catalysts—A Minireview

Nowadays, the reforming of natural gas is the most common of hydrogen or syngas generation process. Each reforming process leads to the achievement of specific goals and benefits related to investment costs. The disadvantage of the reforming process is the need to preclean it mostly from the sulfur and nitrogen compounds. The solution to this problem may be liquefied natural gas (LNG). Liquefied natural gas has recently been seen as an energy source and may be a promising replacement for natural gas. The constant development of the pipeline network, safe transport and a lot of advantages of LNG were contributed to the research development related to the usage of LNG in energy generation technologies. The presented review is a literature discussion on the processing of methane used to produce hydrogen with particular emphasis on the processes of oxy-steam reforming of natural or liquefied natural gas (OSR-LNG). In addition, a key consideration in this article includes Ni catalyst systems used in the oxy-steam reforming of methane or LNG reactions. An analysis of the OSR process conditions, the type of catalyst and the OSR of the methane reaction mechanism may contribute to the development of a modern, cheap catalyst system, which is characterized by high activity and stability in the oxy-steam reforming of natural gas or LNG (OSR-LNG).

Effect of Ag-Addition on the Catalytic and Physicochemical Properties of Ni/ZrO2 Catalyst in Oxy-Steam Reforming of CH4 and LNG Processes

This work presents, for the first time, the catalytic studies of bimetallic Ag-Ni catalysts in the oxy-steam reforming (OSR) of liquefied natural gas (LNG) to hydrogen generation. The physicochemical properties of monometallic Ni and bimetallic catalysts were investigated using various techniques, such as: BET, TPR-H2, TPD-NH3, XRD, TG and SEM-EDS. The catalytic studies showed that the promotion of 20% Ni/ZrO2 catalyst by silver (by 1 or 2 wt.%) improves the efficiency of the produced hydrogen in the oxy-steam reforming of LNG at high temperature. The promotional effect of silver on the reducibility of a Ni/ZrO2 catalyst has been proven. The interactions between Ag and Ni have been proven, and explain the catalytic activity of the catalysts in the investigated processes. TG-DTA-MS results obtained for the spent catalysts proved that the small addition of silver to monometallic nickel catalyst reduces the amount of the carbon deposit formed on the catalyst surface during the oxy-steam reforming of LNG process. Obtained results in this work confirmed that liquid natural gas processing may become an alternative to fossil fuels and confirmed the validity of the hydrogen production via oxy-steam reforming of LNG.

Effect of the support composition on catalytic and physicochemical properties of Ni catalysts in oxy-steam reforming of methane

This work deals with Ni catalysts supported on both mono and binary oxide prepared by a conventional wet impregnation method. The catalytic properties of the material were investigated in oxy-steam reforming of methane (OSRM) process. The physicochemical properties of the catalysts were extensively studied using techniques such as Temperature Programmed Reduction (TPR-H2), Temperature Programmed Desorption of Ammonia (TPD-NH3), Brunauer Emmett Teller Method (BET), X-ray Diffraction studies (XRD), Thermal Analysis coupled with Mass Spectrometry (TG-DTA-MS), Time of Flight Secondary Ion Mass Spectrometer (ToF-SIMS), X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscope with EDX detector (SEM-EDX). The catalytic activity results showed that the Ni/CeO2∙La2O3 (2:1) catalyst exhibited superior activity and high selectivity towards hydrogen formation in the studied process due to the high content of Ni species present on the catalyst surface. The low activity of the Ni catalysts supported on La2O3 or binary oxide with high content of lanthanum oxide is related to the strong interaction of NiO with support.

Hydrogen Production via the Oxy-Steam Reforming of LNG or Methane on Ni Catalysts

Ni catalysts supported on ZrO2, 5%CeO2-ZrO2, and 5%La2O3-ZrO2 were prepared via the impregnation method and tested in the oxy-steam reforming of methane and liquified natural gas (LNG). All tested catalysts exhibited high catalytic activity in the studied process at 700 and 900 °C. The improvement of the stability of Ni catalysts after the addition of CeO2 oxide in the studied oxy-steam reforming of LNG process was confirmed. In addition, high activity and selectivity towards hydrogen was proven in the oxy-steam reforming process at 900 °C over a 20%Ni/5%CeO2-ZrO2 catalyst. It was also proved that the addition of CeO2 onto a ZrO2 carrier leads to a decrease in the NiO and metallic Ni crystallite sizes that were detected by the X-Ray diffraction (XRD) technique. The solid solution formation between NiO and ZrO2 and/or NiO and CeO2 was proved. Superior reactivity in the oxy-steam reforming of CH4 and the LNG process exhibited a 20%Ni/ZrO2 catalyst, which showed the highest methane conversions at 500 and 600 °C, equal to 63% and 89%, respectively. In addition, also in the case of the LNG reforming reaction, the most active catalyst was the 20%Ni/ZrO2 system, which demonstrated 46.3% and 76.9% of the methane conversion value at 500 and 600 °C and the total conversion of others hydrocarbons (ethane, propane and butane). In addition, this catalytic system exhibited the highest selectivity towards hydrogen formation in the oxy-steam reforming of the LNG reaction equal to 71.2% and 71.3% at 500 and 600 °C, respectively. The highest activity of this system can be explained by the uniform distributions of Ni species and their highest concentration compared to the rest of the monometallic Ni catalysts. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) results also confirmed a strong interaction of NiO with ZrO2 in the case of the 20%Ni/ZrO2 catalysts. The presence of selected NiZrO+ ions emitted from the investigated surface of the 20%Ni/ZrO2 system was detected.

Hydrogen Production on Cu-Ni Catalysts via the Oxy-Steam Reforming of Methanol

In this work, bimetallic Cu-Ni catalysts supported on binary oxides containing ZnO, ZrO2, CeO2 and Al2O3 were investigated in hydrogen production via the oxidative steam reforming of methanol (OSRM). Their physicochemical properties were extensively studied using various methods such as BET, TPR-H2, TPD-NH3, XRD, SEM-EDS, ToF-SIMS and XPS. The reactivity measurements showed that the active phase and support composition played an important role in the activity of the catalyst in the OSRM. The most active system at higher temperatures was 30% Cu–10% Ni/CeO2·Al2O3, with high catalytic activity attributed to the Cu0.8Ni0.2 alloy formation. In addition, the reactivity results showed that the most active catalyst exhibited high acidity and was easily reduced. At low temperatures, the best catalytic properties were exhibited by 30% Cu–10% Ni/ZrO2·Al2O3. The reactivity and physicochemical properties of the studied catalysts confirmed the crucial role of alloy composition on their catalytic properties in the oxy-steam reforming of methanol. The obtained results validate the possibility of using Cu-Ni catalysts for hydrogen production.

Thermodynamic modelling and optimization of oxy-reforming and oxy-steam reforming of biogas by RSM

ABSTRACTIn this study, a comparative thermodynamic equilibrium calculation of biogas oxy-reforming and oxy-steam reforming processes to produce syngas has been conducted by Aspen Plus simulation software. The effects of temperature (600–800°C), pressure (1−20 atm), and inlet O2/CH4 (0−1.0), H2O/CH4 (0−3.0), and CO2/CH4 (0.3−1.0) mole ratios on the equilibrium compositions of products were determined. The operation of the process was optimized using Gibbs free energy minimization method and statistical approach: response surface methodology (RSM). Optimum operating conditions CH4/CO2/O2 = 1:0.51:0.12 at 788°C and 1 atm for oxy-reforming and CH4/CO2/H2O/O2 = 1:0.63:0.19:0.07 at 780°C and 1 atm for oxy-steam reforming were obtained to reach maximum H2 yield, CH4 and CO2 conversions by minimizing carbon selectivity to produce syngas for methanol production.

Oxy-steam reforming of methanol\xa0on copper catalysts

The influence of copper content in the monometallic catalysts supported on the CeO2·Al2O3 binary oxide system on their catalytic activity and physicochemical properties in oxy-steam reforming of methanol was investigated. It was shown that activity and selectivity depends on the content of copper, its dispersion on the catalysts surface. It was confirmed that optimal copper content was 20 wt% of Cu. Copper catalysts with 20 wt% of Cu exhibited the highest methanol conversion and reaction rate value compared to the rest of the investigated catalysts systems. The kinetic measurements performed in oxy-steam reforming of methanol on 20%Cu/CeO2·Al2O3 catalysts, showed an activation energy for this system equal Ea (OSRM) = 66.56 kJ/mol.

Rh/CeO2 Thin Catalytic Layer Deposition on Alumina Foams: Catalytic Performance and Controlling Regimes in Biogas Reforming Processes

The application of ceramic foams as structured catalyst supports is clearly expanding due to faster mass/heat transfer and higher contact efficiency than honeycomb monoliths and, mainly, packed beds. In this paper, alumina open-cell foams (OCFs) with different pore density (20, 30 and 40 ppi) were coated with Rh/CeO2 catalyst via a two steps synthesis method involving: (i) the solution combustion synthesis (SCS) to in-situ deposit the CeO2 carrier and (ii) the wet impregnation (WI) of the Rh active phase. The catalytic coatings were characterized in terms of morphology and adhesion properties by SEM/EDX analysis and ultrasounds test. Permeability and form coefficient were derived from pressure drop data. Catalytic performance was evaluated towards biogas Steam Reforming (SR) and Oxy-Steam Reforming (OSR) processes at atmospheric pressure by varying temperature (800–900 °C) and space velocity (35,000–140,000 NmL·g−1·h−1). Characteristics time analysis and dimensionless numbers were calculated to identify the controlling regime. Stability tests were performed for both SR and OSR over 200 h of time-on-stream (TOS) through consecutive start-up and shut-down cycles. As a result, homogenous, thin and high-resistance catalytic layers were in situ deposited on foam struts. All structured catalysts showed high activity, following the order 20 ppi < 30 ppi ≈ 40 ppi. External interphase (gas-solid) and external diffusion can be improved by reducing the pore diameter of the OCF structures. Anderson criterion revealed the absence of internal heat transfer resistances, as well as Damköhler and Weisz-Prater numbers excluded any internal mass transfer controlling regime, mainly due to thin coating thickness provided by the SCS method. Good stability was observed over 200 h of TOS for both SR and OSR processes.

Novel Rh(Pd)-Cu(Ni) supported catalysts for oxy-steam reforming of methanol

Monometallic copper, nickel and bimetallic Pd(Rh)-Cu(Ni) catalysts supported on a binary oxide containing various content of ZrO2 and Al2O3 were prepared by impregnation method. Their physicochemical and catalytic properties in oxy-steam reforming of methanol reaction (OSRM) were extensively investigated. Selecting an optimal composition of the catalyst for the OSRM process was the main goal of this work. The influence of zirconia content on the reactivity and physicochemical properties of supported copper catalysts in OSRM was also studied. The reactivity measurements showed that the supported copper catalyst was more active than the nickel catalyst. The catalytic measurements showed that the catalyst properties depend on their surface composition, acidity and adsorption properties. High selectivity of supported copper catalyst with composition 20%Cu/ZrO2·Al2O3 (Zr:Al = 1:2) towards carbon dioxide and hydrogen was confirmed. In addition, the promotion effect of palladium and rhodium on the activity of monometallic supported copper and nickel catalysts in OSRM was confirmed. The most active system in the OSRM process was 0.5%Rh-20%Cu/ZrO2·Al2O3.

High Active and Selective Ni/CeO2–Al2O3 and Pd–Ni/CeO2–Al2O3 Catalysts for Oxy-Steam Reforming of Methanol

Herein, we report monometallic Ni and bimetallic Pd–Ni catalysts supported on CeO2–Al2O3 binary oxide which are highly active and selective in oxy-steam reforming of methanol (OSRM). Monometallic and bimetallic supported catalysts were prepared by an impregnation method. The physicochemical properties of the catalytic systems were investigated using a range of methods such as: Brunauer–Emmett–Teller (BET), X-ray Powder Diffraction (XRD), Temperature-programmed reduction (TPR–H2), Temperature-programmed desorption (TPD–NH3), X-ray photoelectron spectroscopy (XPS) and Scanning Electron Microscope equipped with an energy dispersive spectrometer (SEM–EDS). We demonstrate that the addition of palladium facilitates the reduction of nickel catalysts. The activity tests performed for all catalysts confirmed the promotion effect of palladium on the catalytic activity of nickel catalyst and their selectivity towards hydrogen production. Both nickel and bimetallic palladium–nickel supported catalysts showed excellent stability during the reaction. The reported catalytic systems are valuable to make advances in the field of fuel cell technology.

Syngas production by steam and oxy-steam reforming of biogas on monolith-supported CeO2-based catalysts

In this study, the syngas production by steam reforming (SR) and oxy-steam reforming (OSR) of clean biogas over cordierite monoliths (400 cpsi) lined with Ni, Rh, or Pt on CeO2 catalyst was deeply investigated. Structured catalysts were prepared by using an alternative method to traditional washcoating based on the combination of the solution combustion synthesis (SCS) with the wetness impregnation (WI) technique. TEM and SEM analysis were used to study the morphology of the catalytic layer and to determine its thickness, while the quality of the coating in terms of adhesion on the monolith was evaluated by ultrasonic treatment in isopropyl alcohol solution. The performance and the stability of the structured catalysts were investigated at different process parameters, namely temperature (700–900 °C), steam-to-carbon (S/C = 1–5) and oxygen-to-carbon (O/C = 0.1–0.2) molar ratios, and weight space velocity (WSV = 30,000–250,000 NmL gcat−1 h−1). The SCS + WI deposition method allowed obtaining a uniform and thin coated layer with high mechanical strength. The following order of activity was exploited: Rh > Pt > Ni for biogas SR and Rh > Pt ≈ Ni for biogas OSR. The Rh-based catalyst exhibited higher activity and long-lasting stability towards biogas SR and OSR reactions for syngas production.

Methanol synthesis from biogas: A thermodynamic analysis

Abstract A new approach for the direct conversion of syngas into methanol has been proposed as alternative to the conventional process requiring WGS and/or PSA clean-up steps for syngas upgrading. A comparative thermodynamic equilibrium analysis of biogas reforming processes (dry reforming, steam reforming and oxy-steam reforming) has been performed using the Gibbs free energy minimization method. The calculations have been carried out under different biogas composition (CH4/CO2 = 1–2.3), reaction temperature (400–900 °C), S/CH4 (0.0–3.0) and O2/CH4 (0.0–0.2) molar ratios. The effects of process variables on the reforming performances as well as on the syngas quality, in term of CH4 and CO2 conversion, H2/CO and H2/CO2 ratios, coke deposition and energetic consumption, has been examined. Subsequently, methanol synthesis has been studied using the same mathematical approach, with the aim to identify the most adequate operating conditions for the direct conversion of the syngas obtained from reforming process into methanol. The simulations suggested that steam reforming of biogas, with high methane content, is the most appropriate route to produce a syngas quality suitable for the new proposed approach.

Influence of the Zn\u2013Al binary oxide composition on the physicochemical and catalytic properties of Ni catalysts in the oxy-steam reforming of methanol

This paper presents the catalytic properties of mono- and bimetallic nickel supported catalysts in the oxy-steam reforming of methanol. The physicochemical properties of the supported catalysts were studied by various techniques such as TPR, TPD-NH3, XRD and BET. A significant impact of palladium and the support composition on the activity and selectivity of nickel catalysts in OSRM was demonstrated. The highest activity in the oxy-steam reforming of methanol reaction among all nickel catalysts was shown by the 20% Ni/ZnO·Al2O3 (Zn:Al = 1:1) catalyst. The acidity results correlate well with the reactivity of the investigated catalysts. The most active monometallic system showed the highest total acidity and was the easiest to reduce compared to the rest of the investigated Ni catalysts. The effect of palladium on the reducibility and reactivity of the nickel supported catalyst was proven. The activity results carried out in the OSRM reaction showed that such catalytic material may be potentially applied in fuel cell technology.