Catalytic Reactor Research Articles

Trans-level multi-scale simulation of porous catalytic systems: Bridging reaction kinetics and reactor performance

Multi-scale porous structures inside and/or between the catalyst pellets or particles are found in many chemical processes, where strong coupling of reaction and transport results in complex apparent reaction kinetics influential to the reactor performance. Traditional continuum-based porous media models and simulation methods can hardly describe such structures and their scale effects faithfully. A trans-level multi-scale discrete computational framework is hence proposed to address this complexity and implemented for an olefin catalytic cracking (OCC) process. The apparent reaction kinetics at the REV (representative elementary volume) scale is obtained by hard-sphere pseudo-particle modeling (HS-PPM), and coupled with computational fluid dynamics / discrete element method (CFD-DEM) for the reactor-level hydrodynamics via a one-dimensional (1D) finite difference scheme for particle-level diffusion. The mesoscales of the REVs and the flow networks between the particles are thus covered by the framework, which are previously described by simple average quantities in the continuum methods. The reactant conversion rate and target product selectivity obtained agree well with experimental results, while a continuum approach may give significantly different and unreasonable results. The multi-scale method is, therefore, demonstrated to be necessary and effective for bridging the intrinsic reaction kinetics with the performance of porous catalytic reactors.

Zeolite-based catalytic membrane reactors for thermo-catalytic conversion of CO2.

Zeolite-based catalytic membrane reactors have been successfully applied in overcoming the thermodynamic limitations of CO2 hydrogenations and dry reforming of methane (DRM) reactions. This review summarizes the zeolites as membrane reactor components regarding the permeance, permselectivity, durability, conversion, selectivity, and stability by referring to the synergy of catalyst and membrane. Also, five operation parameters (temperature, pressure, feed ratio, sweeping gas flow rate, and gas hourly space velocity) are introduced regarding their impacts on the performance of membrane reactor. Besides, synthesis methods and conditions for zeolite membranes are critically illustrated in the category. Moreover, representative surface and structure properties of zeolite membranes are discussed by relating to the synthesis-structure-performance relationships. Finally, conclusive remarks are demonstrated and possible solutions to existing challenges are proposed. So far, this is the first time to discuss the applications of zeolite membrane reactors in the CO2 adsorption, separation, activation, and conversion in reforming and hydrogenation processes.

Three-dimensional cellulose-based hierarchical porous continuous flow catalytic reactor for water purification

Inspired by the saccharum officinarum cellulose frameworks, a naturally hierarchical structured based continuous flow catalytic reactor (ZIF-67@SCF CFR) was constructured, which was employed to reduce 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in an effective and persistent way. The hierarchical structured based saccharum officinarum cellulose frameworks have numerous aligned and open microchannels, abundant porosity, which afford nanometer grade perforation panel and the regular fibrovascular bundles and high-throughput transport and the abundance of highly active sites for growing ZIF-67 nanoparticles. The resulting built hierarchical saccharum officinarum cellulose frameworks continuous flow reactor is as demonstrated by evaluating their activity in a model of catalytic reaction. The resultant ZIF-67@SCF CFR (5 cm length, 15 mm diameter) exhibits superior 4-NP catalytic efficiency up to 100% after 40 min, and the long-term stability of ZIF-67@SCF CFR was verified by continuously using 360 min, maintaining degradation efficiency of 40% after 240 min. Herein, the built ZIF-67@SCF CFR has a certain persistence performance in degrading pollutants as a continuous flow catalytic reactor. And the ZIF-67@SCF CFR has recyclability after freeze-drying and self-assembly processing. Moreover, the results show that the catalytic efficiency of ZIF-67@SCF CFR increases with the growth of diameter and length of reactor. In short, naturally hierarchical structured based biomass material continuous flow reactor like ZIF-67@SCF CFR with the features of natural, renewable, and degradable, has a special consistent of complicated multi-level porous structures, nano-level perforation plates, and regular agreement fibrovascular bundles, which could be employed as a promising candidate to reduce the water pollutants. In this work, we reported a naturally hierarchical structured based saccharum officinarum cellulose frameworks continuous flow reactor (ZIF-67@SCF CFR), becomes an effective persistent usability on water pollution treatment. The resultant ZIF-67@SCF CFR (5 cm length, 15 mm diameter) exhibits superior 4-NP catalytic efficiency up to 100% after 40 min, and the long-term stability of ZIF-67@SCF CFR was verified by continuously. Moreover, we proved that the catalytic efficiency of ZIF67@SCF CFR increase with the growth of diameter and length of reactor. We believe the simple and facile material and method has great potential for reducing the water pollutants

New configuration gas-cooled fluidized bed membrane reactor to reduce the thermodynamic limitations of dimethyl ether production

In this study, a gas-cooled fluidized bed membrane reactor with a new configuration was investigated aiming to reduce thermodynamic limitations in DME production. In this configuration, two Pd-Ag and alumina-silica membranes were used simultaneously for the permeation of hydrogen into the reactor and to remove its containing water, respectively. The heat of the exothermic DME synthesis reactions is removed by heat transfer with sweep and hydrogen gaseous flows. The simulation of the fluidized bed membrane reactor shows that the presence of the membranes increases DME production and carbon monoxide (CO) conversion by about 30.6% and 28.3%, respectively. Enhanced DME production was observed by raising temperature, pressure, and shell and tube side flow rates. Space velocity and H2/CO ratio had an optimum point in DME production. The proposed model can be used for the design of an industrial catalytic membrane reactor for DME production from synthesis gas.

Catalytic Profile Reactor for Multimodal Operando Measurements during Periodic Operation

AbstractMultimodal operando measurement concepts aim to provide structure‐activity relations of heterogeneously catalyzed reactions during operation. While the utilization of multiple characterization and spatiotemporally‐resolved techniques provides complementary information at relevant time and length scales, different reactor operation modes allow to track catalyst dynamics. However, combining these measurement concepts require complex experimental setups with high demands from a strongly interdisciplinary field of reaction engineering, physics and chemistry. In this study, a fully automated and integrated catalytic profile reactor setup is introduced which is capable of measuring spatiotemporally‐resolved species concentration, temperature and catalyst structure information under periodic reaction conditions. The oxidative dehydrogenation of C2H6 to C2H4 over MoO3/γ‐Al2O3 was used as a test system. Using the periodic profile approach, the catalytic system was investigated through activity measurements resolved in time and space combined with reactor simulations and operando high‐energy X‐ray diffraction. The presented catalytic profile reactor setup is a versatile technology, aiming to promote combined and detailed analysis of local catalyst activity and structure, for improved reproducibility and quality of operando measurements.

Investigation of the combustion of exhaust gas recirculation in diesel engines with a particulate filter and selective catalytic reactor technologies for environmental gas reduction

The use of diesel engines has increased dramatically in recent years, as has the number of exhaust emissions. These emissions have the potential to endanger Mother Nature and the living species within it. Governments all over the world have introduced legislative rules on exhaust emission reduction in order to limit the number of emissions released into the environment through the use of global sustainable development technologies. This has compelled automobile manufacturers to create a variety of diesel emission reduction systems, the most important of which are the Diesel Particulate Filter (DPF), Exhaust Gas Recirculation (EGR), and Selective Catalytic Reactor (SCR). The primary goal of this research work is to reduce diesel engine exhaust gas emissions by utilizing emission reduction systems such as DPF, EGR, and SCR. Here, various combinations of the aforementioned emission reduction systems were tested to determine the best possible combination that had the greatest impact on the exhaust gases. The best possible combination depends on the performance of what gases are to be eliminated, keeping the EGR rate at an optimum value between 10% and 20%. If preference is given to reduce NOx, then we will combine 10–20% EGR with SCR, but if the preference is given to reduce HC, CO, and soot, we will use 10% - 20% EGR in combination with a DPF. Overall, the DPF + SCR with 10% EGR rates seems to be an appreciable result.

MHD and Thermal Slip Effects on Viscous Fluid over Symmetrically Vertical Heated Plate in Porous Medium: Keller Box Analysis

The heat transfer characteristics along the non-magnetized shapes have been performed in various previous studies numerically. Due to excessive heating, these mechanisms are less interesting in engineering and industrial processes. In the current analysis, the surface is magnetized, and the fluid is electrically conducting, which is responsible for reducing excessive heating along the surface. The main objective of the present work is to analyze convective heat transfer analysis of viscous fluid flow with thermal slip and thermal radiation effects along the vertical symmetric heated plate immersed in a porous medium numerically. The results are deduced for viscous flow along a magnetized heated surface. The theoretical mechanism of heat and magnetic intensity along a vertical surface is investigated for numerical analysis. The nonlinear-coupled partial differential equations (PDEs) for the above viscous fluid flow mechanism with the symmetry of the conditions normal to the surface are transformed and then converted into non-similar formulations by applying appropriate and well-known similarity transformations for integration and solutions. The final non-similar equations are numerically integrated by employing the Keller box method. The discretized algebraic equations are plotted graphically and numerically on the MATLAB R2013a software package. The main finding of the current analysis is to compute physical quantities such as velocity graph, magnetic field graph, and temperature plot along with their slopes, that is, skin friction, magnetic intensity, and heat transfer for different parameters included in the flow model. First, the velocity graph, magnetic field graph, and temperature graph are obtained, and then their slopes are analyzed numerically along the vertical magnetic surface. It is noticed that fluid velocity is increased at lower magnetic force, but minimum velocity is noticed at maximum magnetic force. It is worth mentioning that with the increase in magnetic force, the magnetic energy increases, which extracts the kinetic energy of the fluid and causes the above-said behavior. Furthermore, the current issues have significant implications for the polymer industries, glass fiber production, petroleum production, fiber spinning, plastic film production, polymer sheet extraction, heat exchangers, catalytic reactors, and the production of electronic devices.

A pseudo-local heat transfer approach in a low tube to particle diameter ratio packed bed catalytic reactor: Oxidative dehydrogenation of ethane as a case study

A generalized approach to model heat transfer in an industrial-scale wall-cooled packed bed reactor with a low tube-to-particle diameter ratio (<8) is proposed and assessed in this work. The modeling approach rests on the realization of experiments carried out in absence of reaction in bench-scale as well as in industrial-scale packed beds. The approximation overcomes historical limitations identified when modeling radial heat transfer mechanisms by applying conventional approaches. The methodology leads to the reliable determination of the external wall heat transfer coefficient and pseudo-local radial effective thermal conductivity. The approach allows the quantification of heat transfer resistances through the core, the internal and the external wall of the bed indicating that approximately 30 % of the resistances are located along the internal side of the packed bed when it was operated at Particle Reynolds numbers ranging from 700 to 1400. Because of its complex impact on heat transfer, fluid dynamics is accounted for by implementing a methodology that uses pressure drop data and the mass conservation criterion to describe velocity profiles, including the determination of the viscous and inertial resistances caused by solid surfaces at the core and near the wall. Finally, the heat transfer information is transferred to a pseudo-heterogenous model to simulate the performance of an industrial-scale wall-cooled packed bed reactor for the highly exothermic oxidative dehydrogenation of ethane. Simulations demonstrate both the reliability of the proposed heat transfer approach and the limitations of the conventional approximations when describing temperature profiles in a packed bed reactor.

Prediction of local concentration fields in porous media with chemical reaction using a multi scale convolutional neural network

The study of solute transport in porous media is of interest in many chemical engineering systems. Some example applications include packed bed catalytic reactors, filtration devices, and batteries. The pore scale modeling of these systems is time consuming and may require large computing resources, for this reason computational fluid dynamics (CFD) simulations are not practical if a large number of simulations is required, like in multiscale modeling, where a model at a large scale calls for pore scale simulations. It has been shown that neural networks can be trained with a dataset of flow simulations and then predict fields orders of magnitude faster, and with less computational resources, in new domains. However, it is crucial to provide the neural network with an effective description of the domain and the undergoing operating conditions to be able to train models that generalize accurately in unseen samples. Therefore, research is needed to employ neural networks in new complex systems. The appropriate training of a network for predicting coupled flow and solute transport processes is an outstanding problem due to the complex interplay between geometry and operating conditions. In this work, we train a multi scale convolutional neural network (MSNet) with a diverse dataset of simulations of transport and chemical reaction in porous media to predict the local concentration fields in images of porous media. Our dataset contains a wide diversity of sphere pack arrangements under different operating conditions (Péclet and Reynolds numbers). We train a robust model by employing different input descriptors that represent the medium and the different operating conditions of each system. Our trained model is able to provide nearly instantaneous predictions, compared to around twenty hours of the CFD workflow, with less than 3.5% error on new geometries and transport conditions. Thus the model could be easily integrated in a multiscale workflow where fast response is needed.

Clean preparation of mixed trivalent and quadrivalent vanadium electrolyte for vanadium redox flow batteries by catalytic reduction with hydrogen

The vanadium redox flow battery (VRFB) is a promising technology for large-scale stationary energy storage systems. However, the high preparation cost of mixed valent vanadium electrolyte hinders the large-scale commercial application of VRFB. In this work, a simple, green and low-cost method is proposed to prepare the mixed valent vanadium electrolyte for VRFB. The clean hydrogen is chosen as the reducing agent to obtain trivalent vanadium ions from quadrivalent vanadium ions. The Pt/C material is used as the catalyst to accelerate the reduction rate at atmospheric pressure. The impurity-free mixed valent vanadium electrolyte, with a mean valence number of 3.5, prepared by the catalytic reduction process exhibits excellent battery performance with CE of 93% and EE of 85%. Furthermore, a catalytic reactor using Pt/C decorated graphite felt is designed and used to continuously produce the mixed valent vanadium electrolyte. According to the result of simple cost analysis, the proposed catalytic hydrogen reduction process can reduce theoretically the manufacturing cost by approximately 22.6% compared with the present industrial electrolytic process. As a consequence, the simple, clean and low-cost manufacture method of the mixed valent vanadium electrolyte exhibits remarkable competitiveness and promising potential for the practical production application of VRFB.

Temperature-Dependent Density and Magnetohydrodynamic Effects on Mixed Convective Heat Transfer along Magnetized Heated Plate in Thermally Stratified Medium Using Keller Box Simulation

The heat transmission properties along the non-magnetized geometries have been numerically obtainedby various researchers. These mechanisms are less interesting in engineering and industrial processes because of excessive heating. According to current studies, the surface is magnetized and the fluid is electrically conductive, which helps to lessen excessive surface heating. The main objective of the current analysis is to numerically compute the temperature-dependent density effect on magnetohydrodynamic convective heat-transfer phenomena of electrical-conductive fluid flow along the vertical magnetized and heated plate placed in a thermally stratified medium. For the purpose of numerical analysis, the theoretical process governing heat and magnetic intensity along a vertical magnetic plate is examined. By using suitable and well-known similarity transformations for integration, the non-linear coupled PDEs for the aforementioned electrical-conductive fluid flow mechanism are changed and subsequently converted into non-similar formulation. The Keller Box method is used to numerically integrate the final non-similar equations. The MATLAB software program plots the transformed algebraic equations graphically and quantitatively. The behavior of the physical quantities such asvelocity graph, magnetic field graph, and temperature plot along with their slopes that arerate of skin friction, the rate of heat transfer, and the rate of magnetic intensity for different parameters included in the flow model. The novelty of the current work is to compute the magneto-thermo analysis of electrically conducting flow along the vertical symmetric heated plate. First, we secure the numerical solution for steady part and then these results are used to find skin friction, heat transfer, and magnetic intensity. In the current work, the fluid becomes electrically conducing due to a magnetized surface which insulates heat during the mechanism and reduces the excessive heating. The results are excellent and accurate because they are satisfied by its given boundary conditions. Additionally, the current problems have a big impact on the production of polymer materials, glass fiber, petroleum, plastic films, polymer sheets, heat exchangers, catalytic reactors, and electronic devices.

Rapid Screening of Kinetic Models for Methane Total Oxidation using an Automated Gas Phase Catalytic Microreactor Platform

AbstractAn automated flow micropacked bed catalytic reactor platform was developed to conduct pre‐planned experiments for rapid screening of kinetic models. The microreactor was fabricated using photolithography and deep reactive ion etching of a silicon wafer, with a reaction channel width and depth of 2 mm and 420 μm respectively. It was packed with ca. 10 mg of 5 wt. % Pd/Al2O3 catalyst to perform methane combustion, which was the selected reaction to test the developed platform. The experimental system was monitored and controlled by LabVIEW to which Python scripts for online design of experiments and data analysis were integrated. Within each experimental campaign, the platform automatically adjusted the experimental conditions, and the analysis of the product stream was conducted by online gas chromatography. The experimental platform demonstrated the capability of identifying the most probable kinetic models amidst potential models within two days.

Highly sulfonated chitosan-polyethersulfone mixed matrix membrane as an effective catalytic reactor for esterification of acetic acid

A new mixed matrix membrane (MMM) incorporating sulfonated polyethersulfone (SPES) and sulfonated crosslinked chitosan (SCCS) as a superior hydrophilic filler was synthesized and applied as a catalytic pervaporation membrane reactor (PMR) for the esterification of acetic acid with ethanol. The optimal conditions for esterification over SPES-SCCS were preliminarily studied using a batch reactor (BR). The synthesis of ethyl acetate was studied in the PMR based on experimental findings of BR esterification. The pervaporative separation of water in the PMR gave it better catalytic performance than the BR. More importantly, the newly developed PMR is permselective towards the ethyl acetate product.

Conversion of pyrolysis vapors derived from non-biodegradable waste plastics (PET) into valuable fuels using nickel-impregnated HZSM5-70 catalysts

Recycling waste plastics into pyrolytic fuels is a highly promising energy-saving approach. The improvement and enhancement of the resulting fuel quality from heavy oil-derived-waste plastics pyrolysis is in high demand. We performed catalytic reforming of heavy oils-derived polyethylene terephthalate (PET) pyrolysis to simultaneously improve the quality of oils into valuable fuels (gasoline-range hydrocarbon) and reduce the oxygenated compounds. Nickel-impregnated HZSM5-70 catalysts were prepared by the wet-impregnation method. The catalytic process was carried out in a catalytic tubular reactor at a constant feeding rate of 2.5 mL/h. In particular, various processing factors were examined by varying the impregnation loading of nickel (2–10 wt%), catalyst mass (1–5 wt%), and process temperature (400–500 °C). Increasing any of the three process parameters resulted in a relatively similar decrease in the quantity of liquid products and an improvement in the quality of reformed products. The best quality of reformed oils were obtained at 5 % catalyst loading and 10 % nickel loading on the catalyst at 450 °C. FT-IR analyses show that raising process parameters has a substantial influence on increasing aliphatic and aromatic hydrocarbon content, while lowering the quantity of undesired products (acids, alcohols, and ketones) in the oils. GC–MS analysis results confirmed that the relative content/area of liquid products predominantly contains gasoline-range hydrocarbons (C5-C12), with a total of 33.39 % on blank-run. The hydrocarbons (C5-C12) production from HZSM5-70 and NiO/HZSM5-70 was greatly enhanced to 66.48 % and 85.05 %, repectively, while the oxygenated compounds, including alcohols, acids, and ketones were reduced from 39.38 to 10.75 % (total area). In comparison to HZSM5-70, the NiO/HZSM5-70 catalyst performs more effectively, retaining its catalytic activity after five cycles (∼3 % decrease). Thus, the NiO/HZSM5-70 exhibits high catalytic performance and reusability.

Facile integration of core–shell catalyst and Pd-Ag membrane for hydrogen production from low-temperature dry reforming of methane

Dry reforming of methane (DRM) is an important way of conversion of CH4 and CO2, two greenhouse gases, for the production of hydrogen. In this study, a catalytic membrane reactor combining an ultra-thin Pd-Ag alloy membrane with a coke-resistant Ni-SiO2@CeO2 core–shell catalyst was developed for high yield hydrogen production from DRM. The performance of membrane in the presence of gases such as CO, CO2 and CH4 was evaluated, and very little reduction in H2 flux (∼2.5 %) was observed in the presence of these gases at the relevant reaction conditions. The catalyst was tested for DRM reaction in both fixed bed reactor (FBR) and catalytic membrane reactor (CMR) to evaluate its performance at different reaction conditions. In a catalytic membrane reactor, the removal of hydrogen resulted in 1.5 times higher methane conversion compared to the calculated conversion at thermodynamic equilibrium at the used reaction conditions when hydrogen is not removed from the reaction mixture. Around 70 % of the produced H2 was recovered from the reaction stream, by virtue of the high H2 flux through the ultra-thin Pd-Ag membrane. Further, the competing reverse water gas shift reaction, that consumes the produced H2, was drastically suppressed by using membrane reactor. The suppression of reverse water gas shift reaction (RWGS) in CMR was confirmed by analyzing downstream gases using gas chromatography mass spectrometer, the result showed significantly lower H2O content for CMR than FBR. Thus, the coupling of ultra-thin membrane with a core shell catalyst synergistically improved the performance of the dry reforming of methane.

Mathematical Modeling and Robust Multi-Objective Optimization of the Two-Dimensional Benzene Alkylation Reactor with Dry Gas

The benzene alkylation reactor using the dry gas is the most significant equipment in the ethylbenzene manufacturing process. In this paper, a two-dimensional homogeneous model is developed for steady state simulation of the industrial multi-stage catalytic reactor for ethylbenzene. The model validation on a practical benzene alkylation reactor shows the model is accurate and can calculate the hot spot temperatures. The composition of dry gas from upstream process varies with the operating conditions, which can cause unexpected hot spots in the reactor and catalyst deactivation. Considering the uncertainty in dry gas composition, a robust multi-objective optimization framework is proposed: first, the back-off in constraints is introduced to the multi-objective optimization problem to hedge against the worst case; then the optimal operating point can be selected using the multi-criteria decision-making. The reactor optimization objectives are maximizing selectivity of ethylene and conversion of ethylbenzene, and the distribution ratios of dry gas are defined as decision variables. Results of robust multi-objective optimization show the selectivity and conversion at the optimal operating point are 90.88% (decreased by 0.24% compared to the practical condition) and 99.94% (increased by 0.72%). Importantly, the proportion of violations of the hot spot constraints decreases from 13.7% of the traditional method to 3.8% by applying the proposed robust multi-objective optimization method.

Comparative life cycle assessment of power-to-methane pathways: Process simulation of biological and catalytic biogas methanation

Power-to-Methane (P2M) pathways are proposed as an innovative solution to utilize surplus renewable electricity for long-term and long-distance storage. This electricity can produce hydrogen using electrolysis and, with the input of CO2 from biogas, be further used for the production of synthetic methane. The methanation reaction can be done with a biocatalyst or nickel catalyst, each with a different pathway of pre- and post-treatment steps. To date, only a limited number of studies have analysed the environmental impact of P2M pathways using life cycle assessment, and no study has directly compared the biological and catalytic P2M pathways. The goal of this research is to close this knowledge gap by quantifying the environmental impact of synthetic methane production and identifying differences between both pathways. Mass and heat balances of both pathways were simulated with AspenPlus and used as basis for a thorough life cycle inventory of the material and energy demand. The global warming potential per MWh synthetic CH4 is similar for the biological and catalytic pathways, but the impact is differently distributed between the processes. The catalytic pathway requires more sulfur removal, compression power and cooling demand. In the biological pathway, the bioreactor has a large impact due to its electricity and nutrient demand, whereas the catalytic reactor's impact is almost negligible.

Nanomaterials with oxygen mobility for catalysts of biofuels transformation into syngas, SOFC and oxygen/hydrogen separation membranes: Design and performance

Modern hydrogen energy technologies include generation of syngas and pure hydrogen from biofuels to be used for green energy production in solid oxide fuel cells (SOFC). To be economically feasible, these processes require design of stable, efficient and inexpensive catalysts, permselective membranes for hydrogen and oxygen separation as well as SOFC cathode and anode materials. In all cases, such materials should possess a high oxygen mobility. This review presents results of our research devoted to design of materials based on complex oxides with fluorite, perovskite, and spinel structures used in these applications. The key aspect is characterization of their oxygen mobility by unique method of temperature –programmed oxygen heteroexchange in flow reactors and finding its dependence on their composition, real structure/microstructure and surface properties affected by methods of synthesis and elucidated with the help of modern structural, spectroscopic and kinetic methods. Optimized materials were shown to provide stable and efficient performance in catalytic reactors, membranes and solid oxide fuels cells.

Calculation Method for Assessing the Storage Capacity of Nitrogen Compounds in LNT Reactors

The presented study describes proprietary calculation methods that simulate the process of storing nitrogen dioxide elevation in a catalytic LNT reactor. The first section’s points of reference are the achievements of the article’s authors and the possibility of modeling NO2 adsorption processes in LNT reactors. The rest of the article presents model calculations (proposed by the authors) of the course of the NO2 storage process in LNT reactors. It considers one in its transition period, affecting the improvement and duration of the adsorption process. The conclusion presents selected results of simulation calculations obtained with the help of the equations’ authors and an evaluation of the results. A review of theoretical considerations is consistent with the experimental data, suggesting that the proposed computational solution may be used in future analytical validity assessments of LNT reactor tools under operating conditions.

Facile synthesis, characterization of alumina supported nickel oxide and cobalt oxide nano composites and determination of their hydrogen enhancement potential

Hydrogen enhancement potential of Alumina supported Nickel and cobalt Oxide Nano composites has been investigate in a downdraft biomass gasifier. The supported bi-metallic Nano composites were synthesize by facile deposition– precipitation (DP) method. The Nano size characterization of the catalyst has been performing using X-ray Diffraction studies (XRD) and High Resolution Scanning Microscope studies (HR- SEM). Using De-Scherer relation and XRD pattern the mean size of the Nano crystallite particles has been founding in the range of 32 nm. The HR-SEM measurements concur with this value. The hydrogen gas enhancement potential were evaluate as function of catalytic reactor temperature. It was observed that hydrogen enhancement levels reached almost 23 vol% at a catalytic bed temperature of 800 °C.