Modeling of biomass-based hydrogen production via catalytic sorption-enhanced reformer integrated with a gasifier

The sorption enhanced reformer concept breaks the thermodynamic limits of steam methane reforming and water-gas shift reactions with selective CO₂ removal to produce more H₂. In this paper, we propose a dynamic kinetic model for sorption-enhanced steam reformers (SERs) integrated with biomass gasifiers. An analysis of operating conditions was conducted to examine high purity hydrogen production. The kinetic model was validated with published literature results at different reactor pressures (5-20 bar), steam/carbon ratios (2-5), and reactor temperatures (673K–1023K). This study shows that biomass gasifiers can be integrated with SER reactors to produce high purity H₂.     

A resource recycling technique of hydrogen production from the catalytic degradation of organics in wastewater

A resource recycling technique of hydrogen production from the catalytic degradation of organics in wastewater by aqueous phase reforming (APR) has been proposed. It is worthy of noting that this technique may be a potential way for the purification of refractory and highly toxic organics in water for hydrogen production. Hazardous organics (such as phenol, aniline, nitrobenzene, tetrahydrofuran (THF), toluene, N,N-dimethylformamide (DMF) and cyclohexanol) in water could be completely de-graded into H2 and CO2 with high selectivity over Raney Ni, and Sn-modified Raney Ni (Sn-Raney-Ni) or Pd/C catalyst under mild conditions. The experimental results operated in tubular and autoclave reactors, indicated that the degradation degree of organics and H2 selectivity could reach 100% under the optimal reaction conditions. The Sn-Raney-Ni (Sn/Ni=0.06) and Pd/C catalysts show better catalytic performances than the Raney Ni catalyst for the degradation of organics in water into H2 and CO2 by the aqueous phase reforming process.     

Reaction parameters influence on the catalytic performance of copper-silica aerogel in the methanol steam reforming

Steam reforming of methanol was carried out on the copper-silica aerogel catalyst.The effects of reaction temperature,feed rate,water to methanol molar ratio and carrier gas flowrate on the H_2 production rate and CO selectivity were investigated.M ethanol conversion was increased considerably in the range of about 240-300,after which it increased at a slightly lower rate.The used feed flowrate,steam to methanol molar ratio and carrier gas flowwere 1.2-9.0 m L/h,1.2-5.0 and 20-80 m L/min,respectively.Reducing the feed flowrate increased the H_2 production rate.It was found that an increase in the water to methanol ratio and decreasing the carrier gas flowrate slightly increases the H2production rate.Increasing the water to methanol ratio causes the lowest temperature in which CO formation was observed to rise,so that for the ratio of 5.0 no CO formation was detected in temperatures lower than 375℃.In all conditions,by approaching the complete conversion,increasing the main product concentration,increasing the temperature and contact time,and decreasing the steam to methanol ratio,the CO selectivity was increased.These results suggested that CO was formed as a secondary product through reverse water-gas shift reaction and did not participate in the methanol steam reforming reaction mechanism.     

Catalytic Transformation of Oxygenated Organic Compounds into Pure Hydrogen

The continual growth in transportation fuels and more strict environmental legislations have led to immense interest in developing green biomass energy. In this work, a proposed catalytic transformation of oxygenated organic compounds (related to bio-oil) into pure hydrogen was desighed, involving the catalytic reforming of oxygenated organic compounds to hydrogen-rich mixture gas followed by the conversion of CO to CO₂ via the water gas reaction and the removal of CO₂. The optimization of the different reforming catalyst, the reaction conditions as well as various sources of oxygenated organic compounds were investigated in detail. The production of pure hydrogen, with the H₂ content up to 99.96% and the conversion of 97.1%, was achieved by the integrated catalytic transformation. The reaction pathways were addressed based on the investigation of decomposition, catalytic reforming, and the water gas reaction.     

含氧有机物催化重整制备纯氢

研究了一种新的利用含氧化合物制备纯氢的催化变换过程,该过程耦合了含氧化合物的催化重整、水煤气变换反应和CO₂去除步骤. 详细研究了重整催化剂的筛选、反应条件以及不同的含氧化合物催化重整行为. 利用所述集成方法获得的最高氢气浓度为99.96vol%和最大转化率为97.1mol%. 此外,通过含氧化合物的解离、催化重整和水煤气变换反应研究,探讨了含氧化合物制备纯氢的相关反应路径.     

Single eye analysis and contralateral eye comparison of tear proteins in normal and dry eye model rabbits by MALDI-ToF mass spectrometry using wax-coated target plates

A study of rabbit tear protein expression in a dry eye rabbit model was performed to determine if a pattern in expressed proteins could be identified. The uniqueness of the model allows the comparison of normal (control) eye tear protein expression with surgically induced dry eye tear protein expression in individual animals. The sensitivity of the method allows for single eye analysis. One-dimensional mini-gel electrophoresis of the tear proteins did not show substantial differences between band patterns of the normal versus the dry eye, but was used to assess the molecular weight ranges of the major proteins. Specific assignments of some of the predominant proteins were obtained by tandem mass spectrometry (MS) which showed that the lower molecular weight lipid-binding proteins (approximately 10 kDa to 36 kDa) constitute a considerable amount of the observed protein, followed in lesser quantities by the transferrins which have higher molecular weights ranging from 70 kDa to 85 kDa. Enhancement of matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) MS linear mode analysis of intact proteins in tear fluid was demonstrated through the use of wax-coated MALDI plates and spot washing. MALDI-ToF MS analysis of the expressed tear proteins illustrates that differences between normal eye tear and dry eye tear protein content are manifested in changes in the lower molecular weight lipid-binding proteins such as lipophilin which exhibits an increase in concentration in the dry eye, and β-2 microglobulin which undergoes a decrease.     

CO2／CH4重整镍基催化剂制备与性能的关系

一般浸渍法与真空浸渍法的比较说明,真空浸渍制备的催化剂,其表面具有较多的Ｎｉ原子,催化活性较高,现场ＴＰＯ实验表明,ＣＯ岐化的积炭量大于ＣＨ４解离的积炭量。从而提出镍基催化剂的积炭主要来自反应生成气ＣＯ的岐化。     

Thermodynamic Assessment of a Solar-Driven Integrated Membrane Reactor for Ethanol Steam Reforming

To efficiently convert and utilize intermittent solar energy, a novel solar-driven ethanol steam reforming (ESR) system integrated with a membrane reactor is proposed. It has the potential to convert low-grade solar thermal energy into high energy level chemical energy. Driven by chemical potential, hydrogen permeation membranes (HPM) can separate the generated hydrogen and shift the ESR equilibrium forward to increase conversion and thermodynamic efficiency. The thermodynamic and environmental performances are analyzed via numerical simulation under a reaction temperature range of 100–400 °C with permeate pressures of 0.01–0.75 bar. The highest theoretical conversion rate is 98.3% at 100 °C and 0.01 bar, while the highest first-law efficiency, solar-to-fuel efficiency, and exergy efficiency are 82.3%, 45.3%, and 70.4% at 215 °C and 0.20 bar. The standard coal saving rate (SCSR) and carbon dioxide reduction rate (CDRR) are maximums of 101 g·m⁻²·h⁻¹ and 247 g·m⁻²·h⁻¹ at 200 °C and 0.20 bar with a hydrogen generation rate of 22.4 mol·m⁻²·h⁻¹. This study illustrates the feasibility of solar-driven ESR integrated with a membrane reactor and distinguishes a novel approach for distributed hydrogen generation and solar energy utilization and upgradation.     

Cu/ZrO2催化剂上乙醇水蒸气重整反应的研究Ⅱ反应条件的影响

采用沉淀法或醇凝胶法、浸渍法制备Cu/ZrO2催化剂,在常压微型固定床石英管反应器上进行乙醇水蒸气重整反应,采用程序升温还原（TPR）技术表征催化剂的还原特性。考察了催化剂还原温度、反应温度、水醇比、空速等对反应的影响以及催化剂的稳定性。结果表明,在300℃～500℃,随反应温度升高,乙醇转化率增大,H2选择性下降。不同还原温度对转化率的影响不是很大,对于H2选择性,300℃、400℃还原的催化剂优于500℃还原的催化剂。高水醇比有利于提高转化率和H2选择性。随空速增大,转化率和H2选择性呈现下降的趋势。8%Cu/ZrO2催化剂在400℃或450℃反应22h显示出良好的稳定性。     

原位核磁共振技术研究共催化剂类型以及光照波长对甲醇光催化重整产物的影响

本文采用原位核磁共振的方法研究了在真实固-液环境中共催化剂类型以及光照波长对甲醇光催化重整产物及光解水产氢产率的影响.结果发现,不同贵金属担载的锐钛矿型二氧化钛催化剂对甲醇光催化重整产物的产量和产率有着不同程度的影响,但是对其动力学特征影响不大.光照波长对甲醇光催化重整产物的产量也影响较大.通过对比甲醇氧化产率与产氢产率,发现共催化剂的种类对光催化反应速率及氧化还原能力起重要作用,且共催化剂的种类会影响体系氧化和还原能力之间的协同性.