Steam Reforming Of Methanol Research Articles

Power/thermal-to-hydrogen energy storage applied to natural-gas distributed energy system in different climate regions of China

This paper presents a novel distributed energy system (DES) with hybrid-hydrogen energy storage, in which the proton exchange membrane electrolyzer (PEMEC) and steam reforming of methanol (SRM) are used to convert surplus power and waste heat into hydrogen. To identify the feasibility of the proposed DES in different climate regions, a case study is performed to choose a rehabilitation hospital in Harbin, Jinan, Wuhan and Guangzhou of China to explore the DES optimal configurations. The mixed integer linear programming model is established and the multi-objective optimization considering annual total cost (ATC) and annual carbon emissions (ACE) is conducted by improved version of augmented ε-constraint (AUGMECON2) method for system optimal configurations. After selecting four cases among Pareto frontiers for each city, the two methods of Analytic Hierarchy Process/Shannon entropy combined with Gray Relation Analysis are performed to determine the most suitable locations. The results show that adding the SRM to DES as a hybrid-hydrogen energy storage system can improve the configuration flexibility, environmental performance and primary energy ratio compared with only-electrochemical hydrogen storage DES. The Pareto frontiers for four cities demonstrate a trade-off between ATC and ACE, and the ACE is decreased by 6.3% with ATC increased by 1.4% in Jinan. Generally, Guangzhou is the best suitable city, and Jinan and Wuhan rank second by two evaluation methods with 0.727 and 0.643 average scores, respectively. The current electricity and natural-gas prices are verified to be beneficial to Jinan to deploy the proposed DES, and Guangzhou and Wuhan present a better economic performance with the minimum ATC decreased by 11.4% and 6.58% under ideal energy prices. The results can provide useful information for hybrid-hydrogen energy storage application to DES in different climate regions.

Mechanism study on gliding arc (GA) plasma reforming: Reaction and energy pathways for H2 production from methanol steam reforming

Aiming on deeply understanding the gliding arc methanol steam reforming (GA-MSR), its reaction mechanism was studied in terms of reaction and energy transfer pathways by combining experiment and plasma kinetics simulation in CH3OH concentration (CME) range of 5%-100%. Via monitoring the consumption and production rates of each species, the roles of species play during GA-MSR are revealed. The important reactive species are identified as H, OH and CH3, which induce the main dehydrogenation pathway of CH3OH→(CH2OH + CH3O) → CH2O → HCO → CO for CH3OH converting to syngas. With the increase of CME, the concentrations of H and CH3 are enhanced, but OH concentration is weakened. The concentration variation trends of the important reactive species regulate that CO2 by-produces at low CME and hydrocarbons do at high CME. In addition, the energy pathways, which are very important but always ignored for plasma reforming, are disclosed advancedly for the energy-strongly coupling GA-MSR. The positive effect of CME on the energy transfer from plasma to chemical energy and the major energy loss pathway of heat loss are uncovered. The energy pathways studies also show why a very high energy efficiency (>80%) could be achieved in GA-MSR, which could be further improved by avoid energy loss from the system.

Novel Cu and Pd-Cu Catalysts Supported on Multi-Walled Carbon Nanotubes for Steam Reforming and Decomposition of Methanol

In this study, multi-walled carbon nanotubes (MWCNTs) were prepared by chemical vapour deposition (CVD) using acetylene as a carbon source over an iron catalyst. As-prepared MWCNTs were used to support modern mono-copper, palladium, and bimetallic palladium-copper catalysts, and their feasibility for hydrogen production was tested during steam reforming of methanol (SRM) and methanol decomposition (DM). The structural characteristics of the MWCNTs were evaluated using the SEM and XRD methods. The physicochemical properties of the monometallic and bimetallic catalysts were analysed using the TPR and XRD methods. The promotion effect of palladium on methanol conversion rate and H2 productivity in the case of the copper catalysts was demonstrated. The enhanced activity of the Cu/MWCNTs after palladium promotion was due to the formation of Pd-Cu alloy compound.

A review study on methanol steam reforming catalysts: Evaluation of the catalytic performance, characterizations, and operational parameters

Conventional fossil-based energy sources have numerous environmental demerits; sustainable and renewable sources are attracting the undivided attention of researchers owing to their valuable physical and chemical features. Several industrial-scale technologies are employing hydrogen as a green energy source as the most preferential source. Not only is hydrogen a potent energy carrier but also it is not detrimental to the environment. Among many other hydrogen production processes, steam reforming of methanol (SRM) is deemed a practical method due to its low energy consumption. Cu, Ni, noble metals, etc., are the salient catalysts in SRM. Many researchers have conducted thorough studies incorporating improvement of the catalysts’ activity, mechanism predictions, and the impacts of operational parameters and reformers. This review concentrates on the SRM catalysts, supports, promoters, and the effect of the operational parameters on the process efficiency and H2 production yield. In this regard, the methanol conversion, H2 and CO selectivity, and operating parameters are notably contingent on the surface characterization and chemistry of the catalysts. Herein, Cu-, Ni-, and noble metal-based catalysts on various metal oxide supports, such as Al2O3 and ZnO, are assessed meticulously in the SRM process from the standpoint of mechanism and catalyst characterization. Most of the peer-reviewed studies had encountered agglomeration, metal particle sintering at high temperatures, coke formation, and deactivation of catalysts as the prevalent barriers. Hence, the novel methods of conquering the above-mentioned obstacles are evaluated in this review. Employment of diverse synthetic methods, bimetallic catalysts, distinct catalyst promoters, and unconventional supports, such as metal–organic frameworks, carbon nanotubes, and zeolites, are the salient routes to overcome the metal dispersion and thermal stability issues. In addition, the influence of operational parameters (temperature of the process, steam/carbon ratio, and feed flow rate) has been weighed painstakingly, along with introducing the research gap and future perspectives in the territory of SRM catalysts.

Probing crystalline phase effect of rare earth metal oxides (REO) on Cu/REO (RE=Gd, Eu, Sm) catalysts for methanol steam reforming (MSR) to produce H2

In this work, to study the phase structure effect, three groups of Cu/REO catalysts were prepared with cubic and monoclinic Gd2O3, Eu2O3 and Sm2O3 supports for MSR reaction to produce H2. Based on CH3OH conversion and H2 yield, the reaction performance of the catalysts ranks as Cu/Sm2O3-M > Cu/Sm2O3–C > Cu/Gd2O3-M > Cu/Gd2O3–C > Cu/Eu2O3-M > Cu/Eu2O3–C. For the same kind of REO, Cu supported on the monoclinic support shows better performance than on the cubic one. Despite the phase structure difference, Sm2O3 is the best support among all the three kinds of REOs. Compared with Cu/REO catalysts prepared with cubic supports, the corresponding catalysts prepared with monoclinic supports generally possess more surface oxygen vacancies, which can generate more surface active oxygen (O2–) and moderate basic sites. Moreover, the contents of Cu + on the catalysts follow the same sequence. The reaction performance is positively related to the amount of these three types of surface sites. But metallic Cu0 species is necessary to maintain the Cu+ ↔ Cu0 redox cycle. Furthermore, on a catalyst with good performance, those vital surface reaction intermediates can be stabilized during the reaction. Cu/Sm2O3-M possesses the largest quantities of these surface sites, and has the appropriate amount of Cu+ and Cu0 after reduction, thereby displaying the optimal performance in all the catalysts. In conclusion, evident support crystal structure effect is observed for Cu/REO catalysts, and a monoclinic phase REO is a better support than the respective cubic phase one.

Steam reforming of methanol over combustion synthesized CuZnOx-based catalysts for fuel cell applications

Steam reforming of methanol is considered an effective way of producing hydrogen-rich reformate for fuel cell applications, with the CuZnOx catalysts to be the most widely used materials for this process. In this study, the incorporation of various promoters in the CuZnOx structure, via a solution-combustion method, was investigated in order to promote the performance of the catalysts in the steam reforming of methanol. The physicochemical results indicated that the Ga promotion can alter the environment of ZnO phase, creating ZnGa2O4 spinels, oxygen vacancies and thus, influencing the interaction with the active phase (strong metal-support interactions). The catalytic studies illustrated that an optimum amount in Ga2O3 (15 wt%) is beneficial in terms of activity and especially, selectivity, while the formation of a CuZnGaAlOx system enhances further the performance. The functionality of the most active material was successfully demonstrated in an integrated internal reforming methanol fuel cell operating at 220 °C.

Unravelling the synergistic promotion effect of simultaneous doping Fe and Cr into Cu-based spinel oxide on methanol steam reforming

The effects of Fe and Cr species on Cu-based supported and spinel oxide catalysts during methanol steam reforming (MSR) reaction and the Cu–Fe–Cr synergy were investigated. Herein, a series of Al2O3 supported catalysts were prepared. And their MSR performance was evaluated. The addition of Fe and Cr had a significant promotion on MSR performance compared with the corresponding Cu-based catalyst. In order to unravel the beneficial effect, CuFe, CuCr, CuAl, CuFeAl, CuCrAl and CuFeCr catalysts were synthesized by the hydrothermal method. And BET, XRD, SEM-EDX mapping, HRTEM, H2-TPR, NH3-TPD, CH3OH-TPD and XPS characterizations were performed. Results showed that CuFeCr catalyst possessed superior MSR behaviors. At the temperature of 260–270 °C, its methanol conversion was maintained above 80% during a time-on-stream stability of 100 h. And it exhibited better fast start-up behaviors than commercial catalyst. In combination with the characterizations, it was assumed that the excellent catalytic performance of the CuFeCr catalyst was attributed to its moderate Cu+ content and Ovac/Oads ratio. And it was the result of the Cu–Fe–Cr synergistic effect.

Techno economic comparison of combustor integrated steam reforming and sorption enhanced chemical looping steam reforming of methanol

Methanol steam reforming (MSR) has gained significant attention for in-situ hydrogen (H2) production. To overcome the high energy requirement in the process, two modified methods such as combustor integrated steam reforming (CISR), and sorption enhanced chemical looping steam reforming (SE-CLSR) are widely used for the production of H2. In the present work, a techno-economic comparison of CISR and SE-CLSR models has been carried out using Aspen Plus V11to assess the economic viability of hydrogen generation by MSR process. SE-CLSR model is developed considering NiO as an oxygen transfer material (OTM). Simulations have been performed to observe a strong dependence of methanol conversion, hydrogen yield, CO selectivity with different operating conditions like temperature, steam to methanol (S/M) ratio, catalyst weight to methanol molar ratio. The sensitivity analysis of the considered models is performed to obtain the optimum operating conditions. The hydrogen production cost is estimated as 2.66 $/kg and 2.79 $/kg from CISR and SE-CLSR processes, respectively.

A combined cooling, heating and power system with energy storage of waste heat to hydrogen

To improve the recovery of waste heat, a natural-gas based combined cooling, heating and power (CCHP) system with waste-heat to hydrogen as energy storage is proposed. In the novel system, the steam reforming of methanol (SRM) is applied in between the internal combustion engine (ICE) and absorption chiller, and integrated with a hydrogen tank and proton exchange membrane fuel cell (PEMFC) for energy storage. The mathematical model is developed to identify the thermodynamic performances of the system in three operation modes (normal, storage, supplemental) under design and off-design conditions, and multi-objective optimization is conducted to explore the optimal system performances. The results show that the overall exergy efficiencies of the three modes and reference system are 41.71 %, 46.34 %, 43.63 % and 40.51 % with given conditions, respectively. Except for ICE, the reactor accounts for 10.2% and 11.1 % exergy destruction ratio in M1 and M2 modes, while PEMFC accounts for 15% in M3 mode due to the chemical reactions. The parametric analysis demonstrates that increasing reaction temperature of SRM, methanol flow rate or working pressure of PEMFC can enhance the system exergy efficiencies for all modes. The optimal points determined by two decision methods are coincident and the energy and exergy efficiencies are 80.50 % and 43.00 %, which have increased by 0.36 % and 3.09 % than that under design conditions. The study constructs a promising scheme for realizing hydrogen storage by recovering the waste heat, and the results have verified the feasibility of the system and provided thermodynamic basis for further system configurations.

Synthesis, characterization, and methanol steam reforming performance of Cu/perovskite-structured catalysts

In the present work, Cu/perovskite-type structures of the general formula Cu/Ca(ZrxTi1-x)O3 (x = 1, 0.8, 0.6) were synthesized via sol-gel process and afterwards using wetness impregnation method to prepare copper-based catalysts. The physicochemical properties of the prepared catalysts were studied using XRD, SEM, NH3-TPD, H2-TPR and TGA analyses. Structural properties of the catalysts were measured through Brunauer-Emmett-Teller analysis (BET). These catalytic systems were also found to be highly active, selective and sustainable. In this regard, methanol conversion, H2 selectivity and CO selectivity were investigated and monitored by gas chromatography (GC). A high methanol conversion with a good selectivity of H2, low CO selectivity and low coke formation were achieved in steam reforming of methanol. Importantly, the morphological features of the synthesized Cu/perovskite-type porous structures contribute in improvement of catalytic activity. An obvious outcome of this study is the remarkable activity of prepared Cu/Ca(Zr0.6Ti0.4)O3 catalyst in methanol steam reforming at 300 °C due to 98.5% methanol conversion and 85.5% hydrogen selectivity.

Structural optimization of 3D printed SiC scaffold with gradient pore size distribution as catalyst support for methanol steam reforming

Porous ceramic catalyst supports can be used for highly efficient methanol steam reforming (MSR) due to their generally high catalyst loading capacity, large specific surface area, and high chemical stability. This paper presents a novel method to design the SiC scaffolds with optimal pore distribution as catalyst supports to enhance the hydrogen production of MSR microreactors. The structural design of the SiC scaffolds was firstly described, then numerical modeling was developed to study the flow and hydrogen production performances of the supports and adopt the steepest ascent method to optimize the pore size distribution of the supports. Then, the optimized SiC supports were printed using direct ink writing of polymer-derived ceramics, then experimental tests were conducted. Both simulation and experimental results showed that the SiC supports with gradient pore size distribution can reduce the pressure drop and improve the methanol conversion rate of the microreactor. Compared with the supports with uniformly distributed pores, the pressure drops of the SiC support with gradient pore size distribution can be reduced by 2.21 % and methanol conversion increased by 13.33 % at inlet flow rate of 40 μl/min and temperature of 280 ℃. This work demonstrated that the potential of using the proposed method to optimize the structural of the catalyst supports for the development of highly efficient MSR microreactors.

Methanol steam reforming kinetics using a commercial CuO/ZnO/Al2O3 catalyst: Simulation of a reformer integrated with HT-PEMFC system

This study provides a kinetic examination of methanol steam reforming (MSR) over a Cu-based commercial catalyst (CuO/ZnO/Al2O3, Alfa Aesar) as a function of CH3OH and H2O partial pressures at 246 °C and 1 atm in a once-through flow reactor. A power rate law was used to best describe the experimental rate data by linear and non-linear regressions at the operating conditions where transport bottlenecks were eliminated. Comparison of the rate parameters indicated that a strong correlation was suggested by non-linear regression giving reaction orders of 0.29 for methanol and 0.09 for water along with a frequency factor of 53.48 (molCH3OH s−1 gcatalyst−1 kPa−0.38) and an activation energy of 65.59 kJ mol−1. A simulation study of the rate equation to analyze an integrated system of a reformer and an HT-PEMFC was also conducted. The results demonstrate that the system has the potential to produce 15 W power output.

UV-Laser ablation enhanced Joule-heating catalyst support for electrified MSR in microreactor

Methanol is a promising hydrogen carrier, where hydrogen-rich gas can be produced by methanol steam reforming (MSR). However, this method of releasing hydrogen is highly energy consuming. Herein, the Joule-heating catalyst support (JHCS) was fabricated by a FeCrAl metal to enhance the efficiency of electrification, replacing the conventional external heating method. The heat can be provided for the reforming reaction directly inside the microreactor by the Joule-heating method. The Joule-heating reactor showed a faster thermal response than the externally heated reactor; the start-up heating time and the time of a start-stop cycle are about 75 % and 50 % of those for external heating, respectively. The methanol conversion rate of the Joule-heating microreactor was 91.45 % at 280 °C, improved by nearly 30 % than the external heating counterpart. The consumed power density of the Joule-heating microreactor was 2 W/cm3, only 15.8 % of external heating (12.61 W/cm3). The reforming efficiency reached 51.91 % without any waste heat recovery measures, about 4 times of the external heating method. Heat transfer simulation verified the minimal radial temperature gradient in the microreactor eliminated by JHCS. The proposed JHCS method demonstrates a uniform microreactor temperature distribution and superior hydrogen production performance with lower power consumption.

Methanol Steam Reforming over La1-xSrxCeO3-δ Catalysts for Hydrogen Production: Optimization of Operating Parameters

In this study, a series of A-site strontium-doped La1-xSrxCeO3-δ (x = 0.2, 0.4, 0.6, 0.8) perovskite catalysts were synthesized via the ethylenediaminetetraacetic acid (EDTA) sol-gel method for hydrogen production by methanol steam reforming. The fresh and the reduced catalysts are characterized by scanning X-ray (XRD), energy dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM) techniques. Results showed that La0.6Sr0.4CeO3-δ exhibited the best performance among the La1-xSrxCeO3-δ catalysts. The operating parameters were optimized to study the catalytic performance of La0.6Sr0.4CeO3-δ, including catalytic temperature, water–methanol ratio (W/M) and liquid hourly space velocity (LHSV). However, the excessive strontium content led to a decrease in hydrogen production amount per unit time, and the high W/M promoted the reverse water–gas shift reaction (RWGS), which resulted in a decrease in CO selectivity and an increase in CO2 selectivity. In addition, the optimal reaction parameters are as follows: reforming temperature of 700 °C; W/M of 3:1; LHSV of 20 h−1. Furthermore, the methanol conversion rate of La0.6Sr0.4CeO3-δ can reach approximately 82%, the hydrogen production can reach approximately 3.26 × 10−3 mol/g(cat)/min under the optimum reaction conditions. Furthermore, La0.6Sr0.4CeO3-δ exhibits high hydrogen selectivity (85%), which is a promising catalyst for MSR application.

Techno-economic assessment of hydrogen production via dimethylether steam reforming and methanol steam reforming

ABSTRACT The present work reports the techno-economic analysis of hydrogen generation using Dimethyl Ether Steam Reforming (DMESR) and Methanol Steam Reforming (MSR) processes. For both processes, steady-state simulation models were developed using Aspen Plus. The two processes are analysed by taking into account the kinetics of the Cu/ZnO/Al2O3 catalyst for MSR and Cu–Ni/γ-Al2O3 catalyst for DMESR in an RPLUG model simulated as a Fixed Bed Reactor (FBR) at a temperature of 250°C and pressure 20 bar. The work dives into heat integration opportunities to reduce the operating cost of the two processes. The article also provides a gist of the approximate cost to produce hydrogen by the two processes by taking into consideration the cost of equipment and utilities involved. It is found that the TAC for DMESR is marginally higher than MSR mainly because of the higher cost of utilities involved. It was also found that NPV for MSR is comparatively higher than DMESR. The article also provides TAC for Selective Methanation of Carbon Monoxide (SMC) for both processes with the purpose of minimising CO.

Catalytic Properties of the Spinel-Like CuxMn3−xO4 Copper Manganese Oxides—An Overview

Copper manganese oxide spinels and related (multiphase) materials with the formula CuxMn3−xO4 are the active catalysts in a wide variety of industrially important processes due to their great diversity in their phase relations, metal ion valence/site distribution, and chemical properties. In this review, we summarize the preparation methods and their effects on the composition, properties, and catalytic properties of various CuxMn3−xO4 catalysts with various Cu/Mn ratios. The main summarized catalytic reactions are the oxidation of carbon monoxide, nitrogen oxide, and hydrogen sulfide and the oxidative removal of organic solvents such as benzene, toluene, and xylene from the air. Some industrially important reactions (steam reforming of methanol or synthesis gas) and the manufacture of organic chemicals (methyl formate, propylene oxide, and benzyl alcohol) catalyzed by CuxMn3−xO4 spinels are also reviewed.

Hydrogen generation by coupling methanol steam reforming with metal hydride hydrolysis.

Methanol steam reforming (MSR) and hydrolysis of metal hydrides are two important hydrogen generation reactions with complementary characteristics. Coupling of the above two reactions leads to better hydrogen generation performance. The CO2 generated from MSR can be absorbed by the hydroxide generated from hydrolysis, leading to higher H2 purity. The hydrolysis heat can be utilized to drive the endothermic MSR reaction. By carrying out MSR on a CaH2-CuO composite, a hydrogen density of 6.56 wt% based on all the reactants with H2 purity higher than 99% can be obtained at 250 °C.

Hydrogen production by steam reforming of methanol by Cu–Zn/CeAlO3 perovskite

In steam reforming of methanol (SRM), the efficacy of CeAlO3 perovskite as a support for a bimetal catalyst was investigated.

Cu nanoparticles confined in siliceous MFI zeolite for methanol steam reforming

The Cu@S-1 catalyst synthesized by the ligand-stabilized strategy shows high stability and activity in the methanol steam reforming (MSR) reaction.

Methanol steam reforming reactor design for efficient photovoltaic-thermochemical power generation

By integrating concentrating PV and methanol steam reforming (MSR) reaction, photovoltaic/ thermochemical (PVTC) hybrid system is an emerging technology for improving the efficiencies and dispatchability of solar power via complementation...