Milliseconds process to produce hydrogen by steam methane reforming （SMR） reaction, based on Ni catalyst rather than noble catalyst such as Pd, Rh or Ru, in micro-channel reactors has been paid more and more attenti...Milliseconds process to produce hydrogen by steam methane reforming （SMR） reaction, based on Ni catalyst rather than noble catalyst such as Pd, Rh or Ru, in micro-channel reactors has been paid more and more attentions in recent years. This work aimed to further improve the catalytic performance of nickel-based catalyst by the introduction of additives, i.e., MgO and FeO, prepared by impregnation method on the micro-channels made of metal-ceramic complex substrate. The prepared catalysts were tested in the same micro-channel reactor by switching the catalyst plates. The results showed that among the tested catalysts Ni-Mg catalyst had the highest activity, especially under harsh conditions, i.e., at high space velocity and/or low reaction temperature. Moreover, the catalyst activity and selectivity were stable during the 12 h on stream test even when the ratio of steam to carbon （SIC） was as low as 1.0. The addition of MgO promoted the active Ni species to have a good dispersion on the substrate, leading to a better catalytic performance for SMR reaction.展开更多
Hydrogen is one of the best energy carriers.Fluidized bed reactor provides a promising approach for hydrogen production. To describe the hydrogen generating rate with methanol steam reforming in fluidized bed reactor ...Hydrogen is one of the best energy carriers.Fluidized bed reactor provides a promising approach for hydrogen production. To describe the hydrogen generating rate with methanol steam reforming in fluidized bed reactor quantitatively, dual-rate kinetic models of the reactions with exponent form were developed, including that of steam reforming reaction(SR) and decomposition reaction(DE).The reaction rate per unit mass of catalyst was related to partial pressures of components. The exponentials in kinetic equations were obtained by linear least-squares method based on the experimental data. The variance homogeneity test(F test) shows that the dynamic models are feasible with high accuracy, which can be used to predict the generating rate of hydrogen under different reaction temperatures and feed flow rates in fluidized bed reactor. The SR and DE activation energy obtained indicates that ESR\ EDE, which can explain the previous observation that the CO_2 selectivity decreased with the temperature increase.展开更多
Methanol steam reforming manifests great potential for generating hydrogen owing to its lower reaction temper-ature(200-300°C)and higher hydrogen/carbon ratio comparing with ethanol and methane reforming.In this ...Methanol steam reforming manifests great potential for generating hydrogen owing to its lower reaction temper-ature(200-300°C)and higher hydrogen/carbon ratio comparing with ethanol and methane reforming.In this case,methanol steam reforming is applied in various renewable energy systems to assist the energy conversion and improve the system efficiency.The performance of methanol steam reforming reaction strongly depends on the catalysts and reactor structure.In this paper,the development of the copper-based,the noble metal-based and the nanomaterial catalysts were summarized by analyzing the effects of different modification methods,which indicates that cutting the cost and simplifying the manufacturing process are the future goal of catalyst modifi-cation.Moreover,the reaction mechanism of different catalyst types was discussed.For the reactor performance,conventional,miniature,micro,and membrane reactors were discussed and compared,where conventional reac-tor with high CO tolerance is more suitable for industrial application while membrane reactor with high H 2 purity and compact structure is ideal for fuel cell technology.The integration of the methanol steam reforming system into renewable power systems was reviewed as well.Methanol steam reforming technology is of great potential in exhaust heat recovery,cogeneration system and other renewable energy field,where more comprehensive researches should be performed.展开更多
针对微细通道反应器内甲醇水蒸汽重整制氢反应,建立了二维稳态多组分传输反应模型。分析了通道几何尺寸的变化对产物的组成以及通道内部温度分布的影响。结果表明,通道长高比的增加能增强通道壁面与流体的换热性能,提高甲醇转化率和产...针对微细通道反应器内甲醇水蒸汽重整制氢反应,建立了二维稳态多组分传输反应模型。分析了通道几何尺寸的变化对产物的组成以及通道内部温度分布的影响。结果表明,通道长高比的增加能增强通道壁面与流体的换热性能,提高甲醇转化率和产物中氢含量,但同时也会造成产物中 CO 含量的增加,影响到质子交换膜燃料电池的正常工作。展开更多
The effects of reaction temperature,input velocity,molar ratio of methanol to water and reaction time on the conversion of methanol,concentration of carbon monoxide and selectivity of carbon dioxide in the micro-chann...The effects of reaction temperature,input velocity,molar ratio of methanol to water and reaction time on the conversion of methanol,concentration of carbon monoxide and selectivity of carbon dioxide in the micro-channel reactor were investigated.The optimum reaction conditions of micro-channel reactor are as follows:reaction temperature is 260℃,input velocity of methanol liquid is 0.04ml/min and ratio of water to methanol is 1.3.At this reaction conditions,the selectivity of carbon dioxide is 94.3% and conversion of methanol is 52.9%.展开更多
基金supported by the National Natural Science Foundation of China(No.21176137) and Petro China
文摘Milliseconds process to produce hydrogen by steam methane reforming （SMR） reaction, based on Ni catalyst rather than noble catalyst such as Pd, Rh or Ru, in micro-channel reactors has been paid more and more attentions in recent years. This work aimed to further improve the catalytic performance of nickel-based catalyst by the introduction of additives, i.e., MgO and FeO, prepared by impregnation method on the micro-channels made of metal-ceramic complex substrate. The prepared catalysts were tested in the same micro-channel reactor by switching the catalyst plates. The results showed that among the tested catalysts Ni-Mg catalyst had the highest activity, especially under harsh conditions, i.e., at high space velocity and/or low reaction temperature. Moreover, the catalyst activity and selectivity were stable during the 12 h on stream test even when the ratio of steam to carbon （SIC） was as low as 1.0. The addition of MgO promoted the active Ni species to have a good dispersion on the substrate, leading to a better catalytic performance for SMR reaction.
基金supported by the National Natural Science Foundation of China(U1361108)
文摘Hydrogen is one of the best energy carriers.Fluidized bed reactor provides a promising approach for hydrogen production. To describe the hydrogen generating rate with methanol steam reforming in fluidized bed reactor quantitatively, dual-rate kinetic models of the reactions with exponent form were developed, including that of steam reforming reaction(SR) and decomposition reaction(DE).The reaction rate per unit mass of catalyst was related to partial pressures of components. The exponentials in kinetic equations were obtained by linear least-squares method based on the experimental data. The variance homogeneity test(F test) shows that the dynamic models are feasible with high accuracy, which can be used to predict the generating rate of hydrogen under different reaction temperatures and feed flow rates in fluidized bed reactor. The SR and DE activation energy obtained indicates that ESR\ EDE, which can explain the previous observation that the CO_2 selectivity decreased with the temperature increase.
基金the National Natural Science Foundation of China(Project Nos.:51876061,51821004).
文摘Methanol steam reforming manifests great potential for generating hydrogen owing to its lower reaction temper-ature(200-300°C)and higher hydrogen/carbon ratio comparing with ethanol and methane reforming.In this case,methanol steam reforming is applied in various renewable energy systems to assist the energy conversion and improve the system efficiency.The performance of methanol steam reforming reaction strongly depends on the catalysts and reactor structure.In this paper,the development of the copper-based,the noble metal-based and the nanomaterial catalysts were summarized by analyzing the effects of different modification methods,which indicates that cutting the cost and simplifying the manufacturing process are the future goal of catalyst modifi-cation.Moreover,the reaction mechanism of different catalyst types was discussed.For the reactor performance,conventional,miniature,micro,and membrane reactors were discussed and compared,where conventional reac-tor with high CO tolerance is more suitable for industrial application while membrane reactor with high H 2 purity and compact structure is ideal for fuel cell technology.The integration of the methanol steam reforming system into renewable power systems was reviewed as well.Methanol steam reforming technology is of great potential in exhaust heat recovery,cogeneration system and other renewable energy field,where more comprehensive researches should be performed.
基金supported by the National Natural Science Foundation of China(No.51806103)the Natural Science Foundation of Jiangsu Province(No.BK20231445)the Fundamental Research Funds for the Central Universities(No.501XTCX2023146001)。
文摘针对微细通道反应器内甲醇水蒸汽重整制氢反应,建立了二维稳态多组分传输反应模型。分析了通道几何尺寸的变化对产物的组成以及通道内部温度分布的影响。结果表明,通道长高比的增加能增强通道壁面与流体的换热性能,提高甲醇转化率和产物中氢含量,但同时也会造成产物中 CO 含量的增加,影响到质子交换膜燃料电池的正常工作。
文摘The effects of reaction temperature,input velocity,molar ratio of methanol to water and reaction time on the conversion of methanol,concentration of carbon monoxide and selectivity of carbon dioxide in the micro-channel reactor were investigated.The optimum reaction conditions of micro-channel reactor are as follows:reaction temperature is 260℃,input velocity of methanol liquid is 0.04ml/min and ratio of water to methanol is 1.3.At this reaction conditions,the selectivity of carbon dioxide is 94.3% and conversion of methanol is 52.9%.
