Methanol Steam Research Articles

Stability analysis and multi-objective optimization of methanol steam reforming for on-line hydrogen production

The potential solution to hydrogen storage and transportation challenges is provided by liquid fuel-based on-line hydrogen production. An online hydrogen production device has been constructed and the stable output of hydrogen at 6.8 bar under dynamic conditions of 6–13 Nm3/h has been achieved. To achieve optimal economic and thermodynamic performances, the mathematical models for mass, energy, and techno-economics are constructed based on field test data. The Non-Dominated Sorting Genetic Algorithm is employed to update temperature splitting points between multi-stage heat exchangers, targeting multi-objective optimization of heat exchange area, system energy efficiency, and annual average cost. Pareto optimal solutions indicate that such optimization can improve system energy efficiency by 0.03%–3.76% and decrease the hydrogen production cost from 0.004 $/kg to 0.599 $/kg. This work demonstrates the feasibility and effectiveness of multi-objective optimization for online hydrogen production system design and offers important guidance for decision-making in heat exchange network schemes.

Kinetic Characterization of Pt/Al2O3 Catalyst for Hydrogen Production via Methanol Aqueous-Phase Reforming

Compared to steam reforming, methanol aqueous-phase reforming (APR) converts methanol to hydrogen and carbon dioxide at lower temperatures, but also displays lower conversion rates. Herein, methanol APR is studied over the active Pt/Al2O3 catalyst under different operating conditions. Studies were conducted at different temperatures, pressures, methanol mass fractions, and residence times. APR performance was evaluated in terms of methanol conversion, hydrogen production rate, hydrogen selectivity, and by-product formation. The results revealed that an increase in operating pressure and methanol mass fraction had an adverse effect on the APR performance. Conversely, it was found that hydrogen selectivity was unaffected by the operating pressure and residence time for the methanol feed mass fraction of 5%. For the methanol feed mass fraction of 55%, hydrogen selectivity was improved by operating pressure and residence time. The alumina support phase change to boehmite as well as sintering and leaching of the catalytic particles were observed during catalyst stability experiments. Additionally, a comparison between methanol steam reforming (MSR) and APR was also performed.

Performance evaluation and energy management strategy of drone methanol reforming fuel cell hybrid power system: A case study

The performance of hydrogen production by methanol steam reforming and high temperature proton exchange membrane fuel cells on drone lacks the comparison of experimental data, resulting in the overall performance improvement of the system is difficult to evaluate. Therefore, the energy management strategy of methanol reforming high temperature proton exchange membrane fuel cell hybrid power system and state machine is designed and optimized. The performance of this system is analyzed and compared with the flight experiment data of a proton exchange membrane fuel cell hybrid UAV. The results show that the SOC of the system can be stabilized between 70 and 80 during the long cruise phase. The test results show that the maximum hydrogen storage mass density of the hydrogen supply system is increased by 67.6%. The flight time of the system under economic cruise flight of the drone is improved by 29.1%–44.9% with different quality of fuel. Under the maximum flight speed of a certain wind speed, the system can meet the flight requirements and increase the flight time by 31.9% and 17.6% respectively under the wind speed of 1.5 m/s and 4 m/s. Its flight time has been greatly improved, and it has great potential as a drone system.

Maximizing the hydrogen content for methanol steam reforming processes by using the novel pareto-based multi-objective evolutionary algorithms

This research focuses on the methanol-steam reforming (MSR) process to produce hydrogen-rich syngas. A thermodynamic equilibrium reactor was designed for the process, using the Peng-Robinson fluid package for all liquid and gas components. This research aims to reveal the collective impacts of three main parameters—reaction temperature (RT) (100–500 °C in 50 °C intervals), reactor pressure (RP) (1–7 atm in 2 atm intervals), and methanol-to-water (MtW) molar ratio (0.25, 0.5, 1, 2, and 4 atm)—on syngas composition. Additionally, Pareto-based multi-objective evolutionary algorithms (MOEAs), including Multimodal Multi-Objective Differential Evolution with Improved Crowding Distance (MMODE_ICD), Multi-Objective Slime Mould Algorithm (MOSMA), and Improved Multi-Objective Manta-Ray Foraging Optimization (IMOMRFO), were used to maximize hydrogen composition at the reactor outlet. Using these algorithms, the operating parameters for the MSR were optimized. The highest hydrogen content achieved under these conditions was 67.90% among syngases. However, it could be increased by 7.22% with MMODE_ICD, 6.92% with MOSMA, and 4.71% with IMOMRFO algorithms. Furthermore, the algorithms predicted actual data with error margins of 1.1% for MMODE_ICD, 0.28% for MOSMA, and 3.52% for IMOMRFO. In conclusion, this research demonstrates that Pareto-based multi-objective evolutionary algorithms are very effective tools for increasing hydrogen production in MSR processes.

Methanol steam reforming over copper supported on apatites

Low-temperature methanol steam (MSR) reforming over Cu is an efficient process for releasing H2 from this promising liquid hydrogen carrier but the Cu contents of commercial catalysts are often exceedingly high. Here we show that Sr-exchanged fluoro and hydroxyapatites with 1wt.% Cu exhibit very high methanol turnover frequencies up to 386h-1 and H2 production rates up to 6569mol H2 kgCu-1 h-1 with CO selectivity as low as ~0.25% at 250 °C. Formaldehyde and methyl formate are the only other byproducts which are especially observed over catalysts with low Sr/P ratio in the hydroxyapatite. The reforming proceeds through methoxy, formaldehyde and formate species according to in situ FTIR and mass spectrometric measurements. The spectroscopic analyses further reveal the involvement of apatitic HPO42- ions in the catalytic sequence. Thus, the catalytic synergy between Cu and apatites provides a basis for highly efficient, bifunctional MSR catalysts with low copper content.

A conical spiral methanol steam reforming reactor for spectral splitting-based concentrating photovoltaic-thermochemical hybrid production

The spectral beam splitting (SBS) photovoltaic-thermochemical hybrid system improves the solar thermal energy grade through photon energy cascade distribution and methanol steam reforming (MSR) reaction. Given the deficiency of MSR reactor development for dish-concentrating SBS systems, the conical spiral structure is introduced to the receiver/reactor in this work, thus facilitating efficient absorption of circular beams and ameliorating the adaptability of the production. Based on specially designed spectral beam splitter, the Monte Carlo ray tracing (MCRT) method is employed to simulate the non-imaging optical process and optimized reflective cone structure. Thermodynamics and kinetic models of the reactor are established and experimentally validated. The analysis results show that the reflective cone advances the optical efficiency of the reactor to 76.95%, and the conical spiral structure helps to enhance heat and mass transfer for utilization of the catalytic space. The mid/low-temperature reaction prefers a solution flow rate of less than 1.53 mL·s-1 and a water-methanol ratio of 1.4-1.9, with the maximum solar thermochemical conversion rate of 54.5%. Moreover, the upgrading in photothermal and photovoltaic heat exceeds respectively 0.62 and 8.97 at less than 600 W·m-2 of irradiation, demonstrating the adaptive potential of the reactor. In summary, the research results contribute to broadening the operating conditions of the hybrid production and the full-spectrum penetration of solar energy in distributed scenarios.

Numerical study on induction heating enhanced methanol steam reforming for hydrogen production

Electromagnetic induction heating technology, characterized by its non-contact thermal heat transfer, diminished thermal inertia, and facile temperature management, is applied in this study to enhance catalytic methanol steam reforming (MSR) reaction process. A two-dimensional reactor model was developed integrating electromagnetic field coupling with MSR reactions, fluid dynamics and heat transfer. In the reactor, heat is induced instantaneously on the magnetic material through an electromagnetic induction process, which generated by renewable electricity. Results showed that the Internal - Double Row Cylinder (IN-DRC, cylinder means that the shape of induction heating element is cylindrical.) highest heating efficiency is 38.3%, which is limited by the kinetics of MSR reaction. Here, thermal efficiency reaches its maximum with the reaction channel outlet temperature reaching about 580 K. Internal - Double Row Cylinder (IN-DRC) and Internal - Double Row Ball (IN-DRB, ball means that the shape of induction heating element is spherical) methanol conversions are virtually identical, with a maximum value close to 100%. Furthermore, the findings that the adoption of internal induced heating, in contrast to external heating, across the four reactor designs can effectively mitigate temperature gradient within the reactors. This reduction in thermal disparity significantly amplifies methanol conversion within the reactor, thereby markedly enhancing its overall performance in hydrogen production.Therefore, non-contact internal induction heating method has the potential for substantially hydrogen production processes.

Development of integrated thermally autonomous reformed methanol-proton exchange membrane fuel cell system

This paper presents a novel thermally autonomous reformed methanol fuel cell (RMFC) system for highly efficient hydrogen production and power generation by integrating a self-heating methanol steam reforming (MSR) microreactor and a high temperature proton exchange membrane fuel cell (HT-PEMFC). The RMFC system would exhibit significant potential for portable use due to its high energy efficiency, compact size and long lifetime. The structural design of the RMFC system including MSR microreactor and HT-PEMFC are studied, and a work flow is developed to enable the startup and stable power output of the system. After that, the microreactor and HT-PEMFC are fabricated, and then integrated to develop the system. Experimental testing results showed that the microreactor can produce a maximum reformate gas of 541 ml/min with a methanol conversion larger than 93.8 %., while maintaining the carbon monoxide concentration below 2 %. The RMFC system can start up within 17 min, the temperature fluctuation is lower than 6.28 % and the maximum output power can reach up to 32.9 W. As for a conservatively designed rating power of 25 W, the calculated energy conversion efficiency of the system can reach about 28.5 %, with good stability during long-term operations.

Research Progress on Characteristics of On‐Line Hydrogen Production by Methanol Steam Reforming

On‐line hydrogen production via methanol steam reforming (MSR) has gained considerable interest due to its high efficiency, affordability, and eco‐friendliness. Currently, this technology has been widely applied in the industry and has become an important method for hydrogen energy production. However, there are still some issues with this technology, such as short catalyst lifespan and CO pollution, which require further research and improvement. This article provides a comprehensive review of the research progress made in this field, with a particular focus on the catalyst development, reaction mechanism, theoretical calculation, and reactor design. Additionally, the challenges and prospects of on‐line hydrogen production by MSR are also discussed. In conclusion, MSR technology for hydrogen production has vast application prospects and development potential. It will be further explored in‐depth and extensively in future research.

Numerical analysis of catalytic reaction kinetics in methanol steam reformer with variable cross-sectional channel

ABSTRACT Methanol steam reforming (MSR) is a hydrogen production method recognized for its low harmful emissions and high cost-effectiveness. In this study, a three-dimensional numerical model of MSR within channels of variable cross-section. A quantitative relationship between local equilibrium constants and channel structural parameters was established based on the partial pressures of the components. Additionally, the mechanisms by which variable cross-sectional channel structural parameters regulate MSR reaction performance were quantitatively analyzed, considering fluid dynamics, hydrogen production efficiency, and chemical kinetics rates. The results indicate that the kinetic rate of MSR and local equilibrium constants are significantly influenced by the modulation of variable cross-sectional channel structural parameters, with a maximum variation of 50.6%. A positive correlation between methanol conversion rate and the local equilibrium constant of MSR was observed. Utilizing channel structural parameters to enhance MSR led to an 8.75% increase in methanol conversion rate within the same reaction volume. These conclusions may provide theoretical support for regulating volumetric reactions through variable cross-sectional channel structural parameters.

Regulating N-Cu/MoxC interfacial effect coupling β-Mo2C/γ-MoC phase engineering to achieve efficient hydrolysis dissociation and methanol dehydrogenation for hydrogen production

Methanol steam reforming (MSR) is a promising solution for achieving the integration of hydrogen storage, transportation, and in-situ supply. However, it is limited by the slow rate of hydrogen generation and low selectivity. This study constructed a highly active N-Cu/MoxC catalyst with strong interaction between Cu and MoxC, effectively enhancing methanol activation, hydrolysis, and hydrogen production efficiency. Under optimized condition, the 2.8 N-Cu/MoxC catalyst achieved a remarkable H2 productivity of 147.9 mmol gcat−1 h−1 and H2 selectivity of 65.7 %. N induced a partial transition from β-Mo2C phase to γ-MoC phase, resulting in a doubling of H2 production rate. The interfacial N-Cu-MoxC sites facilitated highly reactive efficient CH bond dissociation to convert CO+4H and OH activation, as well as the highly efficient CO reforming. Additionally, temperature programmed surface reaction and isotope testing futher coroborated its superiority in methanol dehydrogenation and hydrolysis dissociation. These discoveries can provide guidance for the design of advanced MSR catalysts.

High purity H2 resource from methanol steam reforming at low-temperature by spinel CuGa2O4 catalyst for fuel cell

Methanol steam reforming (MSR) is an effective way to provide high purity hydrogen for PEMFCs, however the main challenge is the toxic effect of CO. In this study, CuGa2O4 spinel catalyst was applied first for MSR at low temperature. The properties of catalysts were characterized by various techniques, the MSR catalytic performance was also studied in deeply. The surface of the catalyst is composed of particle chains that are interconnected, forming high-volume pores that increase the specific surface area. The catalyst also has a rich porous structure, exposing more active sites. Furthermore, the presence of oxygen vacancies facilitates the adsorption of reactive oxygen species, reducing CO generation. A possible pathway for methanol dehydrogenation has been determined using DFT calculations. The relatively low overall energy barrier on the catalyst surface facilitates methanol activation. Among the steps, formaldehyde dehydrogenation is the rate-determining step in the methanol dehydrogenation process. The CuGa2O4 catalyst exhibits good gas selectivity, with a hydrogen selectivity of 98 % and CO selectivity of 0. and no deactivation occurred within 50 h, demonstrating outstanding durability. These features allow it to serve as an efficient catalyst for MSR online hydrogen production and direct supply to PEMFCs.

Analysis and optimization of energy conversion for an on-board methanol reforming engine with thermochemical recuperation

Methanol steam reforming (MSR) is a promising method to address the storage and safety issues of hydrogen-fueled engines. This method can also significantly improve engine efficiency by recovering exhaust heat. Additionally, low temperature combustion technology can effectively mitigate the issue of excessively high NOx emissions in hydrogen internal combustion engines. However, research on the integration of low temperature combustion technology with methanol steam reforming is limited, and the design of reformers and strategies for methanol reforming remains underdeveloped. Therefore, a one-dimensional model of the methanol steam reforming engine system was established, and methanol reforming strategies were evaluated under varying engine loads. Further a multi-objective optimization of the reformer was conducted to balance system efficiency and economy. The results indicate that complete methanol reforming is unattainable at mid to high loads due to significant turbo work. A partial methanol reforming strategy, where part of the methanol is directly combusted in the cylinder and the rest is reformed to produce hydrogen, achieves the highest system efficiency. After multi-objective optimization of the reformer, this MSR engine yielded a 5.54% increase in average overall system efficiency under three loads, compared to not using thermochemical recuperation.

Cu0·1In0·01/S-1 catalysts with high efficiency towards methanol steam reforming

Cu0·1/S-1, Cu0·1Zn0·01/S-1, Cu0.1Inx/S-1 (x = 0.01, 0.03, 0.05) and Cu0·1Ce0·01/S-1 were successfully prepared with S-1 as the carrier material and applied to methanol steam reforming (MSR) reaction. To further explore its chemical and physical properties, XRD, BET, SEM-EDS, ICP, FTIR, H2-TPR, NH3-TPD, CO2-TPD, and Raman were used to characterize the synthetic S-1 zeolite catalysts. The measured physicochemical properties revealed that utilizing S-1 zeolite as the carrier effectively altered the size of the metal particles, enhancing their dispersion and reduction characteristics. Compared with five different types of S-1 zeolite catalysts, the Cu0·1In0·01/S-1 catalyst has a large specific surface area and pore size. It exhibited superior active metal dispersion, with the lowest reduction temperature for the active metal CuO. The catalyst also showed a high Lewis acid content on its surface, forming the In-Lewis acid site. Consequently, the Cu0·1In0·01/S-1 catalyst exhibits exceptional performance in methanol steam reforming for hydrogen production reactions. It exhibited the best performance with a methanol conversion rate of 100%, H2 selectivity of 100% under the conditions of 1 MPa, 250 °C, the S/C molar ratio of 2.5, and the WHSV of 0.5 h−1, which outperforms most of the reported catalysts in methanol steam reforming.© 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Superlong Metal-Organic Framework Nanowire Fabricated via Steam-Assisted Conversion.

1D nanomaterials have attracted great attention due to their outstanding anisotropic and linear structures. A facile method is developed to fabricate 1D copper metal-organic framework nanowires (Cu-MOF-NW) through steam-assisted conversion from Cu-MOF precursors. During the steam-assisted conversion, Cu-MOF precursor gradually dissolves in methanol steam, and then recrystallized into Cu-MOF-NW, which shows high aspect ratio of about 600 and identical crystal structure of MOF-74. As-prepared Cu-MOF-NW with multiscale porous structure can effectively remove cationic dyes even in dye mixture. Moreover, Cu-MOF-NW, as an ideal template, is calcined to form Cu nanoparticle-doped carbon nanofiber with maintaining its 1D morphology, which shows excellent electrocatalytic activity for the non-enzymatic sensing of glucose.

Comprehensive evaluation and optimization strategy of solar-driven methanol steam reforming for hydrogen production

In the current era of green energy transformation and hydrogen utilization, there is a pervasive interest in thermochemical hydrogen production using solar energy. This study proposes an innovative strategy for the comprehensive evaluation and optimization of a novel solar-driven methanol steam reforming hydrogen production system. The solar-to-chemical conversion and utilization process were simulated via a comprehensive model, incorporating a kinetic model to calculate the reaction process within the photothermal reactor. Furthermore, an integrated evaluation system based on Taguchi's design, ANOVA, and gray relational analysis was constructed to optimize the objectives of methanol conversion, hydrogen yield, and CO selectivity. The results revealed that the catalyst weight to inlet methanol molar rate operating parameter significantly influenced system performance compared to the inlet temperature and steam-methanol ratio. The multi-objective optimized operating factors resulted in the highest methanol conversion (99.99 %), the highest hydrogen yield (3.196), and the lowest CO selectivity (1.71E-3). Additionally, a interaction factor analysis model is introduced to evaluate the interaction effects between each factor. The results indicate consistent optimal values and corresponding operating conditions across these methods for the system proposed in this study. This study offers valuable insights and guidance for the practical operation of solar-driven thermochemical hydrogen production reactions.

Invitro Antibacterial, Antioxidant and XRF Analysis of <i>Commelina Diffusa Burm.F. </i>Plant Extracts

Ethiopia has a long history of using medicinal herbs for treating both human and animal illnesses. Nonetheless, not enough research has been done on the antibacterial properties and possible bioactive components of the majority of medicinal plants. Therefore, this study deals with the evaluation of phytochemical, antimicrobial, antioxidant activities, phenol content and XRF analysis of <i>Commelina Diffusa Burm.F. </i>plant extracts. Mean values of the antimicrobial activity, MIC, antioxidant activities, phenol content and XRF analysis were reported as mean ± standard deviation. The chloroform leaf extracts of the plant gave the highest yield 23.4% followed by methanol 22.27%. The presence of several metabolite components, including alkaloids, diterpenes, flavonoids, glycosides, phenol, protein, saponin, steroids, tannins, terpenoids, tri-terpenoids and amino acids, has been shown by qualitative phytochemical analysis of plant parts. Significant antibacterial activity against the test bacterial strains was demonstrated by steam extracts of<i> Commelina Diffusa Burm.F. </i>Moreover, the methanolic extract of the plant demonstrated notable antioxidant activity. The highest value of phenolic content was obtained in <i>Commelina Diffusa Burm.F. </i>steam methanol extract followed by leaf extract while <i>Commelina Diffusa Burm.F. </i>root extract shows lower phenolic content. In this study, threaten elements were determined in the <i>Commelina Diffusa Burm.F. </i>plant part by using XRF spectroscopy. Overall, this research contributes to the understanding of pharmacological potential of <i>Commelina Diffusa Burm.F. </i>and highlights the importance of further exploring its medicinal properties. The findings provide valuable insights into utilizing medicinal plants for disease treatment and support the development of natural therapeutic agents.

Oxygen vacancy engineering in ZnO/ZrO2 composite catalysts for highly enhanced hydrogen production by methanol steam reforming

The ZnO/ZrO2 binary catalyst system has been an emerging and promising catalyst for efficient production of H2 through methanol steam reforming (MSR). Herein, ZrO2 supports with different crystalline phases were prepared by the oxygen vacancy engineering strategy of Li doping, and then ZnO/ZrO2 catalysts were prepared by the isovolumic impregnation method. The different quantities of doped Li have been found to have a significant impact on dominant crystal phase of ZrO2 supports, which dictates the interaction between ZnO and ZrO2 and the number of oxygen vacancies. In comparison with ZnO/ZrO2-20Li and ZnO/ZrO2-40Li catalysts with predominate tetragonal and monoclinic crystal phase, ZnO/ZrO2-3Li with a mixed crystalline phase exhibits higher catalytic activity for methanol conversion (XCH3OH) and CO selectivity (SCO). Complete methanol conversion of the best performing ZnO/ZrO2-3Li catalyst was observed at a very low CO selectivity of 3.1 % at 375 ℃. The XRD, UV, and XPS characterization results indicate that the strong interaction between ZrO2 and ZnO leads to the appearance of large amount of oxygen vacancies at the ZnO/ZrO2 interface, which greatly improves the performance of the catalyst. ZnO/ZrO2 catalyst showed remarkable stability without obvious deactivation after 32 hours of continuous testing. This work highlights the effectiveness of oxygen vacancy engineering of the ZnO/ZrO2 catalysts for applications in methanol steam reforming and other heterogeneous catalytic systems.

Investigation of a solar-assisted methanol steam reforming system: Operational factor screening and computational fluid dynamics data-driven prediction

The development of solar-to-fuel technologies has received significant attention while facing the growing interest in clean energy production. To accurately evaluate and optimize the solar-assisted thermochemical hydrogen production process, a reliable prediction method that ensures stable accuracy is essential. We utilized a gray correlation analysis (GRA) and a multi-objective genetic algorithm (GA) model to optimize the operating parameters of a methanol steam reforming system. Computational fluid dynamics simulations provided the response values for key parameters, including reactant conversion rate, syngas product yield, and CO selectivity. Additionally, the Taguchi’s method and analysis of variance (ANOVA) were employed to assess the impact of operating parameters on these target outputs. The results demonstrate that the proposed GA-Back propagation neural networks (GA-BPNN) model significantly outperforms traditional prediction models in accuracy, exhibiting robustness and generalization. The mean absolute percentage error (MAPE) of methanol conversion, hydrogen yield, and CO selectivity is 3.20 %, 4.69 % and 3.53 %. The GRA-GA-BPNN model shows a slight decline, while still maintains reliable prediction accuracy, with the MAPE value of 5.76 %, 5.11 %, and 10.4 %. This operational factor screening-based prediction model proves useful for large-scale data-driven predictions of solar thermochemical systems, especially under complex and variable external conditions and internal human interventions.

Research on the characteristics of hydrogen production by methanol steam reforming in a Fresnel lens concentrated tubular reactor

The methanol steam reforming process involves variable heat absorption along the flow direction, resulting in a non-uniform temperature within the reactor. To improve the hydrogen production performance, this paper introduces an innovative solar-driven reactor, the Fresnel Lens Concentrated Collector Tubular Reactor (FLCCTR), which matches solar energy collection with the endothermic reforming process through optimized design. The heat flux density on the reactor's inner wall was determined using the Monte Carlo method. Subsequently, a 3D model was developed that integrates flow, heat and mass transfer, along with reforming kinetics. This model assessed the effects of inlet flow rate, temperature, steam-to-methanol ratio, and heat flux density type on hydrogen production performance. Results indicate that the inlet flow rate significantly affects performance, with the reactor maintaining a minimal radial temperature difference of 3.554K. It also indicated that non-uniform heat flux reduces the temperature increase and CO output by 36.84% at the outlet.