Dry Reforming Of Biogas Research Articles

Impact of Thickness of Pd/Cu Membrane on Performance of Biogas Dry Reforming Membrane Reactor Utilizing Ni/Cr Catalyst

The present study pays attention to biogas dry reforming for the purpose of producing H2. It is known that biogas contains approximately 40 vol% CO2, causing a decrease in the efficiency of power generation due to its lower heating value compared to natural gas, i.e., CH4. We suggest a hybrid system composed of a biogas dry reforming membrane reactor and a high-temperature fuel cell, i.e., a solid oxide fuel cell (SOFC). Since biogas dry reforming is an endothermic reaction, we adopt a membrane reactor, controlled by providing a non-equilibrium state via H2 separation from the reaction site. The purpose of the present study is to understand the effect of the thickness of the Pd/Cu membrane on the performance of the biogas dry reforming membrane reactor with a Pd/Cu membrane as well as a Ni/Cr catalyst. The impact of the reaction temperature, the molar ratio of CH4:CO2 and the differential pressure between the reaction chamber and the sweep chamber on the performance of the biogas dry reforming membrane reactor with the Pd/Cu membrane as well as the Ni/Cr catalyst was investigated by changing the thickness of the Pd/Cu membrane. It was revealed that we can obtain the highest concentration of H2, of 122,711 ppmV, for CH4:CO2 = 1:1 at a reaction temperature of 600 °C and a differential pressure of 0 MPa and using a Pd/Cu membrane with a thickness of 40 μm. Under these conditions, it can be concluded that the differential pressure of 0 MPa provides benefits for practical applications, especially since no power for H2 separation is necessary. Therefore, the thermal efficiency is improved, and additional equipment, e.g., a pump, is not necessary for practical applications.

Catalyst Development for Biogas Dry Reforming: A Review of Recent Progress

Amidst the rapid expansion of the global economy, the demand for energy has escalated. The depletion of traditional energy sources coupled with environmental pollution concerns has catalyzed a shift towards the development and utilization of clean, renewable energy. Biogas, as a renewable energy source, provides diverse applications and holds the potential to alleviate energy shortages. Recently, biogas dry reforming technology has garnered substantial attention as a significant pathway for renewable energy utilization, particularly in the development and optimization of catalysts. Contemporary research predominantly focuses on enhancing the activity and stability of catalysts, with particular emphasis on their resistance to coking and sintering. This review delineates the classification of biogas dry reforming catalysts, their catalytic activity, and issues related to carbon deposition, contrasting biogas dry reforming with traditional dry reforming in catalyst design. It synthesizes numerous studies from recent years aimed at mitigating carbon deposition during the biogas dry reforming process and boosting catalytic activity via active components, carriers, and promoters in both precious and non-precious metal catalysts. Furthermore, it discusses the current challenges of biogas dry reforming technology and outlines prospective future development trends. This discussion provides an in-depth understanding of biogas dry reforming technology and catalyst design, offering insights and recommendations for future research and industrial applications.

Performance of An Energy Production System Consisting of Solar Collector, Biogas Dry Reforming Reactor and Solid Oxide Fuel Cell

Performance of An Energy Production System Consisting of Solar Collector, Biogas Dry Reforming Reactor and Solid Oxide Fuel Cell

The Characteristics of a Ni/Cr/Ru Catalyst for a Biogas Dry Reforming Membrane Reactor Using a Pd/Cu Membrane and a Comparison of It with a Ni/Cr Catalyst

The Characteristics of a Ni/Cr/Ru Catalyst for a Biogas Dry Reforming Membrane Reactor Using a Pd/Cu Membrane and a Comparison of It with a Ni/Cr Catalyst

Development of Ni–Mo carbide catalyst for production of syngas and CNTs by dry reforming of biogas

Biogas has been widely regarded as a promising source of renewable energy. Recently, the direct conversion of biogas over heterogeneous catalysts for the simultaneous production of syngas and carbon nanotubes exhibits a high potential for full utilization of biogas with great benefits. Involving the combined dry reforming of methane and catalytic decomposition of methane, the efficiency of process is strongly depended on the catalyst activity/stability, mainly caused by carbon deposition. In this study, Ni–Mo catalyst is engineered to provide a life-long performance and perform high activity in the combined process. The surface modification of catalysts by a controlled carburization pretreatment is proposed for the first time to produce a carbide catalyst along with improving the catalyst stability as well as the reactivity for direct conversion of biogas. The performance of as-prepared carbide catalysts is investigated with comparison to the oxide and metallic ones. As a result, the Ni–Mo2C catalyst exhibited superior activity and stability over its counterparts, even though the condensed nanocarbon was largely grown and covered on the surface. In addition, up to 82% of CH4 conversion and 93% of CO2 conversion could remain almost constant at 800 °C throughout the entire test period of 3 h under a high flowrate inlet stream of pure biogas at 48,000 cm3 g−1 h−1. The XPS spectra of catalysts confirmed that the presence of Mo2C species on the catalyst surface could promote the stability and reactivity of the catalyst, resulting in higher productivity of carbon nanotubes over a longer time.

Performance Analysis of Hydrogen Production for a Solid Oxide Fuel Cell System Using a Biogas Dry Reforming Membrane Reactor with Ni and Ni/Cr Catalysts

The present study aims to analyze the performance characteristics of the biogas dry reforming process conducted in a membrane reactor using Ni/Cr catalysts and to compare these characteristics with those obtained using pure Ni catalysts. The effect of the pre-set reaction temperature, the molar ratio of CH4:CO2 and the pressure difference between the reaction chamber and the sweep chamber on the characteristics of biogas dry reforming is analyzed. In the present work, the molar ratio of the supplied CH4:CO2 is varied to 1.5:1, 1:1 and 1:1.5. In this case, CH4:CO2 = 1.5:1 simulates a biogas. The pressure difference between the reaction chamber and the sweep chamber is varied to 0 MPa, 0.010 MPa and 0.020 MPa. The reaction temperature is changed to 400 °C, 500 °C and 600 °C. It is revealed that the highest concentration of H2 is achieved using a Ni/Cr catalyst when the molar ratio of CH4:CO2 is 1.5:1 at the differential pressure of 0.010 MPa and the reaction temperature of 600 °C. Under this condition, the H2 yield, H2 selectivity and thermal efficiency are 12.8%, 17.5% and 174%, respectively. The concentration of the H2 produced using a Ni/Cr catalyst is larger than that produced using a Ni catalyst regardless of the pre-set reaction temperature, the molar ratio of CH4:CO2 and the differential pressure.

Investigation of effects of sulfur on dry reforming of biogas over nickel–iron based catalysts

The aim of this study is to maintain and increase the activity of the catalyst in the presence of H2S with the addition of iron to the Ni catalyst. Alumina-supported monometallic iron and bimetallic nickel-iron catalysts with different weight percentages (8% Fe, 3% Ni – 3% Fe and 8% Ni – 8% Fe) were synthesized using the wet impregnation method in this study. Alumina was prepared by the sol-gel method. The activities of these synthesized catalysts in the methane dry reforming reaction were investigated at different H2S concentrations (0 ppm, 2 ppm, and 50 ppm) with a total flow rate of 60 mL/min containing an equimolar ratio of CH4, CO2, and Ar at 750 °C and atmospheric pressure. To investigate the effect of sulfur compounds on the catalytic activity, the catalysts were also exposed to different gas compositions such as the mixture of H2S + He, H2S + CO2 + He, and H2S + CO2 + CH4 + He. In this case, FT-IR with a gas cell was used to determine the components in the gas stream at the reactor outlet. To explain catalytic performance, characterization studies were carried out using XRD, N2 adsorption/desorption, DRIFT, SEM, TGA, and XPS analysis. All-synthesized materials showed Type-IV isotherm with a hysteresis loop corresponding to an ordered mesoporous structure. The DRIFT analysis showed a decrease in the Lewis acid sites after the addition of iron into the Ni-catalysts. In the activity test carried out in the presence of 50 ppm H2S, it was observed that the iron-containing 8Ni–8Fe@SGA catalyst increased the sulfur resistance slightly, compared to the monometallic 8Ni@SGA catalyst. TGA analysis showed that Fe addition reduced coke deposition, as the Ni–Fe catalyst had a lower nickel crystal size than the Ni-based catalyst. FTIR analysis with a gas cell showed that sulfur in H2S transformed to other sulfur compounds such as COS and/or SO2 during dry reforming of biogas over alumina-supported Ni–Fe catalysts.

Effect of ceria content in Ni–Ce–Al catalyst on catalytic performance and carbon/coke formation in dry reforming of CH4

In this study, to enhance the catalytic activity and minimize the carbon/coke formation, cerium incorporated alumina-supported new Ni–Ce–Al catalysts were investigated in dry reforming of biogas. Ni–Ce–Al catalysts were synthesized by the modified one-pot sol-gel method in an inert environment. To determine the effect of the Ce/Al ratio on physicochemical properties of catalysts and their activity, Ni (5 wt %) catalysts with different Ce/Al ratios (0/1, 1/2, 1/1, 2/1 b y wt.) were tested in a fixed-bed flow reactor using an equimolar ratio of CH4/CO2/Ar gas mixture. To explain the correlation between catalytic activity and catalyst properties, characterization studies were carried out by using N2 adsorption-desorption isotherms, XPS, XRD, SEM-EDS, TEM, ICP-OES, DRIFT, O2-TPO and TGA methods before and after activity tests. XRD analysis showed that both CeO2 and γ-Al2O3 crystalline phases with metallic Ni having different peak intensities were separately formed in all the catalysts. Among the catalysts of different Ce/Al ratios, the Ni–1Ce–1Al catalyst containing equal amounts of Al and Ce has the smallest CeO2 crystallite size. This catalyst also has the highest pore diameter and volume. XPS analysis showed that Ce incorporation into the Ni-based Al2O3 catalyst decreased the NiAl2O4 formation. DRIFT analysis indicated that the addition of ceria into the support material decreased the Lewis acidity of alumina. During 25-h long-term activity test, the conversions of CH4 and CO2 obtained with the catalyst Ni–1Ce–1Al (Ce/Al ratio is 1/1) were approximately the same and averaged 76% and 85%, respectively. This behavior of the catalyst indicates its high stability. TGA, XRD and SEM analyzes performed with the used Ni–1Ce–1Al and Ni–Al catalysts show very little carbon formation in the catalyst containing equal weights of Ce and Al compared to the catalyst without Ce. This result shows that the addition of cerium to the catalyst structure prevents carbon deposition due to its special oxygen mobility. This study showed that the crystallite size of CeO2 in the catalyst structure strongly influences preventing carbon accumulation in the dry reforming reaction.

Investigation of Ba doping in A-site deficient perovskite Ni-exsolved catalysts for biogas dry reforming

This work presents the development of an A-site deficient La0.9−xBaxAl0.85Ni0.15O3 (x = 0, 0.02, 0.04, and 0.06) perovskite oxide catalyst for dry reforming of model biogas. The catalysts are prepared using a citrate sol-gel method and used for biogas dry reforming at 800 °C for feed ratios (CH4/CO2) of 1.5 and 2.0. The fresh and spent catalysts are analyzed using XRD, FTIR, TPD, XPS, FESEM, TEM, TPR, TGA-DTA, and Raman analysis. The XRD analysis exhibits the host perovskite oxide structure and the exsolved Ni phase for all prepared catalysts. The partial doping of Ba improves the metal support interaction and oxygen vacancies that enhance catalytic activity and stability, as revealed by the TPR and XPS analysis. The stability experiment on La0.9−xBaxAl0.85Ni0.15O3, for x = 0 catalyst resulted in reduced activity due to the catalyst deactivation by sintering, as confirmed by XRD and FE-SEM. Among all the catalysts studied, La0.84Ba0.06Al0.85Ni0.15O3 (LB6AN-15) exhibited the highest catalytic stability with CH4, and CO2 conversions are 60% and 93%, respectively, for 40 h time-on-stream due to the strong metal support interactions, high oxygen vacancies, and anti-sintering of exsolved Ni nanoparticles in biogas dry reforming.

Nanoparticle Exsolution from Nanoporous Perovskites for Highly Active and Stable Catalysts.

Nanoporosity is clearly beneficial for the performance of heterogeneous catalysts. Although exsolution is a modern method to design innovative catalysts, thus far it is predominantly studied for sintered matrices. A quantitative description of the exsolution of Ni nanoparticles from nanoporous perovskite oxides and their effective application in the biogas dry reforming is here presented. The exsolution process is studied between 500 and 900°C in nanoporous and sintered La0.52 Sr0.28 Ti0.94 Ni0.06 O3±δ . Using temperature-programmed reduction (TPR) and X-ray absorption spectroscopy (XAS), it is shown that the faster and larger oxygen release in the nanoporous material is responsible for twice as high Ni reduction than in the sintered system. For the nanoporous material, the nanoparticle formation mechanism, studied by in situ TEM and small-angle X-ray scattering (SAXS), follows the classical nucleation theory, while on sintered systems also small endogenous nanoparticles form despite the low Ni concentration. Biogas dry reforming tests demonstrate that nanoporous exsolved catalysts are up to 18 times more active than sintered ones with 90% of CO2 conversion at 800°C. Time-on-stream tests exhibit superior long-term stability (only 3% activity loss in 8h) and full regenerability (over three cycles) of the nanoporous exsolved materials in comparison to a commercial Ni/Al2 O3 catalyst.

Coke-resistance over Rh–Ni bimetallic catalyst for low temperature dry reforming of methane

Methane and carbon dioxide can be converted into syngas using the prospective dry reforming of methane technology. Carbon deposition is a major cause of catalyst deactivation in this reaction, especially at low temperature. The superior stability of bimetallic catalysts has made their development more and more appealing. Herein, a series of bimetallic RhNi supported on MgAl2O4 catalysts were synthesized and used for low temperature biogas dry reforming. The results demonstrate that the bimetallic RhNi catalyst can convert CH4 and CO2 by up to 43% and 52% over at low reaction temperature (600 °C). Moreover, the reaction rate of CH4 and CO2 of RhNi–MgAl2O4 remains stable during the 20 h long time stability test, most importantly, there was no obviously carbon deposition observed over the spent catalyst. The enhanced coking resistance should be attributed to the addition of a little amount of noble metal Rh can efficiently suppress dissociation of CHX∗ species into carbon, and the high surface areas of MgAl2O4 support can also promote the adsorption and activation of carbon dioxide to generate more O∗ species. Balancing the rate of methane dissociation and carbon dioxide activation to inhibit the development of carbon deposition is a good strategy, which provides a guidance for design other high performance dry reforming of methane catalysts.

Heat Transfer Analysis and Energy System Evaluation on Solar Collector for Heat Source of Biogas Dry Reforming Assumed to be Installed in Nagoya

Heat Transfer Analysis and Energy System Evaluation on Solar Collector for Heat Source of Biogas Dry Reforming Assumed to be Installed in Nagoya

An Energy Production System Powered by Solar Heat with Biogas Dry Reforming Reactor and Solid Oxide Fuel Cell

An Energy Production System Powered by Solar Heat with Biogas Dry Reforming Reactor and Solid Oxide Fuel Cell

Dry reforming of biogas in a pilot unit: Scale-up of catalyst synthesis and green hydrogen production

A pilot experimental unit was constructed to produce synthesis gas from the dry reforming (DR) of biogas, and its operation was monitored during reaction assays. A scale-up was performed on synthesizing a Ni granulated catalyst, supported on mesoporous silica. The catalyst activity was evaluated under processes of induced deactivation, followed by regeneration during a 90-h reaction. The reaction variables studied included the volumetric composition of the inlet gas flow to the reactor (40–70%CH4 and 60-30%CO2), metal content (5–20% by mass), and inlet gas flow rate (684–2844 L h−1). The catalyst with the metal content of 20% provided the best conversions (99%CH4 and 97%CO2). The experimental pilot unit is capable of producing 575 L h−1 of green H2 from biogas. The regeneration step effectively eliminated coke from the catalyst surface, resulting in the recovery of catalytic performance.

High coke resistance Ni-SiO2@SiO2 core-shell catalyst for biogas dry reforming: Effects of Ni loading and calcination temperature

In this study, Ni-SiO2@SiO2 core-shell catalysts were prepared using the ammonia evaporated synthesis method, followed by encapsulation by a silica layer. The effect of nickel content and calcination temperature on the catalytic activity were separately studied in the biogas dry reforming reaction. The results revealed that the catalytic activity improved and carbon deposition increased when nickel content increased from 2.5 to 15 wt.%. Ni-SiO2@SiO2 with 10 wt.% Ni loading exhibited stable and high methane and CO2 conversions with negligible carbon formation during 12 h time on stream at 700 °C. Also, because of the high carbon resistance property of the prepared catalysts, the CH4 conversion over Ni-SiO2@SiO2 catalyst remained constant at 52% for 12 h at a low reaction temperature of 600 °C. Compared with Ni-SiO2@SiO2 core-shell catalyst, Ni/SiO2 supported catalyst fabricated by impregnation method exhibited lower activity and stability. High stability and carbon deposition resistance properties of the Ni-SiO2@SiO2 catalyst were ascribed to the strong Ni-SiO2 interaction and coverage of the Ni particles by SiO2, which make them resistant against migration and sintering. The results indicated that the catalytic activity gradually improved with the augment of calcination temperature from 600 to 800 °C. Ni-SiO2@SiO2 catalyst calcined at 800 °C with moderate nickel size and intermediate Ni-SiO2 interaction demonstrated the best catalytic activity.

Investigation of La0.6Sr0.4Co1-xNixO3-δ (x=0, 0.2, 0.4, 0.6, 0.8) catalysts on solid oxide fuel cells anode for biogas dry reforming

The introduction of catalyst on anode of solid oxide fuel cell (SOFC) has been an effective way to alleviate the carbon deposition when utilizing biogas as the fuel. A series of La0.6Sr0.4Co1-xNixO3-δ (x = 0, 0.2, 0.4, 0.6, 0.8) oxides are synthesized by sol-gel method and used as catalysts precursors for biogas dry reforming. The phase structure of La0.6Sr0.4Co1-xNixO3-δ oxides before and after reduction are characterized by X-ray diffraction (XRD). The texture properties, carbon deposition, CH4 and CO2 conversion rate of La0.6Sr0.4Co1-xNixO3-δ catalysts are evaluated and compared. The peak power density of 739 mW cm−2 is obtained by a commercial SOFC with La0.6Sr0.4Co0.4Ni0.6O3-δ catalyst at 850 °C when using a mixture of CH4: CO2 = 2:1 as fuel. This shows a great improvement from the cell without catalyst for internal dry reforming, which is attributed to the formation of NiCo alloy active species after reduction in H2 atmosphere. The results indicate the benefits of inhibiting the carbon deposition on Ni-based anode through introducing the La0.6Sr0.4Co0.4Ni0.6O3-δ catalyst precursor. Additionally, the dry reforming technology will also help to convert part of the exhaust heat into chemical energy and improve the efficiency of SOFC system with biogas fuel.

Toward syngas production from simulated biogas dry reforming: Promotional effect of calcium on cobalt-based catalysts performance

The upgrading of simulated biogas with an equal mole ratio of methane and carbon dioxide through dry reforming over calcium promoted on cobalt-based catalysts was investigated in this work. Catalysts with different loading of calcium oxide were synthesized and used to explore that the calcium loading is critical in the performance of catalysts. At low calcium dosages in a range of 0.1–0.2 wt%, the average Co3O4 crystalline size decreased from 8.15 nm to 6.01–7.43 nm, suggesting well-dispersed cobalt on the surface. In addition, the reducibility and basicity of catalysts were also enhanced with a sufficient addition of promoters. The optimal catalyst, 0.2Ca-10Co/Al2O3, exhibited the best performance with roughly 84% and 89% of CH4 and CO2 conversions, respectively. Moreover, the coke formation was suppressed by 78.72%, enabling higher activity and long-lasting stability. The findings offer new opportunities to enhance the dry reforming of simulated biogas performance using earth-abundant catalysts.

Reforming of model biogas using Ni/CeO2/γ-Al2O3 monolith catalyst

This study aims to develop a Ni-Ce coated alumina cordierite monolith for reforming model biogas. Dry reforming of biogas (DRBG) experiments are carried out at 800 °C for various ratios of CH4/CO2, mainly 1.0, 1.5, and 2.0. A 2 × 2 cm monolith is wash-coated with alumina and loaded with Ni-Ce by the wet impregnation method. For improving metal support interactions, the monoliths are calcined at 800 °C for 20 h and reduced in the presence of H2. The catalysts exhibited a CH4 conversion of 91%, 60%, and 48% and CO2 conversions of 60%, 80%, and 81% for a feed ratio of 1.0, 1.5, and 2.0, respectively. The prepared catalysts are characterized by employing various techniques such as XRD and FESEM incombined with EDS and Raman analysis. XRD of calcined catalysts displayed the phases of CeO2, Al2O3, NiO, NiAl2O4, and the monolith peaks and catalysts showed a stable activity for 40 h time-on stream for all the ratios. The Raman and FESEM analysis of spent catalysts reveal the presence of carbon deposition. However, catalysts showed high activity due to active Ni particles present on the top of the carbon nanotubes.

Techno-economic Analysis of Biogas Conversion to Liquid Hydrocarbon Fuels through Production of Lean-Hydrogen Syngas

Large-scale biogas plants are a viable source of CH4 and CO2 to be converted efficiently into high-value products. Specifically, production of liquid hydrocarbons can enhance the availability of green fuels while achieving significant CO2 reductions on site. In this study, the production of liquid hydrocarbons is simulated by dry reforming of biogas into lean-hydrogen syngas, further converted in CO hydrogenation and oligomerization reactors. The process was modeled by using CHEMCAD based on published experimental results with the projected feed composition. A high molar feed ratio of CO2/CH4 (>1.7) was set for the reformer to minimize steam requirement while avoiding carbon formation and reaching an optimal H2 to CO molar ratio (0.7). Two options were techno-economically evaluated based on a biogas plant with a capacity of 5000 N m3/h that produces between 13.8 and 15.7 million liters per year of blending stock for transportation fuels. The economics of the process depends mainly on the cost and availability of the biogas. The minimum selling price of the liquid fuels is $1.47/L and $1.37/L for options 1 (once-through conversion of syngas to liquid fuels) and 2 (recycle of tail gas from oligomerization reactor), respectively, and can be significantly reduced in case the biogas throughput is increased to >20 000 N m3/h. Recycling of the tail gas (option 2) yielded higher productivity, resulting in higher carbon yield (77.9% on the basis of methane) and energy efficiency (67.1%). The economic viability of the process can be improved by implementing CO2 tax or other incentives to reduce capital investment. It provides a potential route for efficient conversion of biogas into liquid hydrocarbons to meet the increased demand for renewable fuels as blending stock in the transportation sector while improving the sustainability of the plant.

Future Paradigm of 3D Printed Ni-Based Metal Organic Framework Catalysts for Dry Methane Reforming: Techno-economic and Environmental Analyses.

Dry reforming of biogas is referred as an attractive path for sustainable H2 production over decades. Meanwhile, in the Malaysian context, the abundance of palm oil mill effluent (POME) produced annually is deemed as a potential renewable source for renewable energy generation. Conventionally, nickel (Ni) is the most common catalyst used in the industrial-scale dry reforming of methane (DRM) to yield H2, but it is subject to the drawbacks of sintering and deactivation after a long reaction time at high temperatures (>500 °C). Therefore, this work aims to provide an insight on the feasibility of the application of modified Ni-based catalysts in DRM, specifically in the economic and environmental aspects. From the benchmarking study of various Ni-based catalysts (e.g., bimetallic (Ni-Ce/Al2O3), alumina support (Ni/Al2O3), protonated titanate nanotube (Ni-HTNT), and unsupported), the Ni-MOF catalyst, notably, had proven its prominence in both economic and environmental aspects on the same basis of 10 tonnes of H2 production. The MOF-based catalyst not only possessed a better economic performance (net present value 61.86%, 140%, and 563.08% higher than that of Ni-Ce/Al2O3, Ni/Al2O3, and Ni-HTNT) but also had relatively lower carbon emissions (13.18%, 20.09%, and 75.72% lower than that of Ni/Al2O3, Ni-HTNT, and unsupported Ni). This work also accounted for 3D printing technology for the mass production of Ni-MOF catalysts, where the net present value was 2 to 3% higher than that of the conventional production method. Additionally, sensitivity analysis showed that the H2 price has the greatest impact on the feasibility of DRM as compared to other cost factors.