氢气蒸汽平衡与优化系统设计与分析

本文针对洛阳石化氢气蒸汽的产耗现状,构建以实时监控、统计分析、管网模拟、产耗预测及调度优化为主要功能模块的信息化系统,实现对公用介质排放、存储、输送、消耗等全过程的精细化管控,为企业的提质增效提供有力支撑工具。

天然气蒸汽转化制氢装置能耗分析

主要对天然气蒸汽转化-变压吸附(PSA)氢气提纯装置在生产不同氢气纯度、不同产氢规模的工况下进行能耗分析,从而为不同的需求客户提供参考依据。

Hydrogen Production by Low-temperature Steam Reforming of Bio-oil over Ni/HZSM-5 Catalyst

We investigated high catalytic activity of Ni/HZSM-5 catalysts synthesized by the impregnation method, which was successfully applied for low-temperature steam reforming of bio-oil. The influences of the catalyst composition, reforming temperature and the molar ratio of steam to carbon fed on the stream reforming process of bio-oil over the Ni/HZSM-5 catalysts were investigated in the reforming reactor. The promoting effects of current passing through the catalyst on the bio-oil reforming were also studied using the electrochemical catalytic reforming approach. By comparing Ni/HZSM-5 with commonly used Ni/Al2O3 catalysts, the Ni2O/ZSM catalyst with Ni-loading content of about 20% on the HZSM-5 support showed the highest catalytic activity. Even at 450 ℃, the hydrogen yield of about 90% with a near complete conversion of bio-oil was obtained using the Ni2O/ZSM catalyst. It was found that the performance of the bio-oil reforming was remarkably enhanced by the HZSM-5 supporter and the current through the catalyst. The features of the Ni/HZSM-5 catalysts were also investigated via X-ray diffraction, inductively coupled plasma and atomic emission spectroscopy, hydrogen temperature-programmed reduction, and Brunauer-Emmett-Teller methods.

轻油蒸气转化催化剂积炭研究进展

分析了轻油蒸气转化催化剂积炭原因和积炭机理;介绍了国内外对各种抗积炭性单金属和双金属催化剂的研究进展;评述了催化剂制备工艺、载体和助剂抗积炭的研究进展。

Hydrogen Production by Catalytic Steam Reforming of Bio-oil, Naphtha and CH4 over C12A7-Mg Catalyst

Hydrogen production by catalytic steam reforming of the bio-oil, naphtha, and CH4 was investigated over a novel metal-doped catalyst of （Ca24Al28O64）^4＋·4O^-/Mg （C12A7-Mg）. The catalytic steam reforming was investigated from 250 to 850℃ in the fixed-bed continuous flow reactor. For the reforming of bio-oil, the yield of hydrogen of 80% was obtained at 750℃, and the maximum carbon conversion is nearly close to 95% under the optimum steam reforming condition. For the reforming of naphtha and CH4, the hydrogen yield and carbon conversion are lower than that of bio-oil at the same temperature. The characteristics of catalyst were also investigated by XPS. The catalyst deactivation was mainly caused by the deposition of carbon in the catalytic steam reforming process.

Techno-economic Analysis of Distributed Hydrogen Production from Natural Gas

It is well established that hydrogen has the potential to make a significant contribution to the world energy production.In U.S.,majority of hydrogen production plants implement steam methane reforming(SMR) for centralized hydrogen production.However,there is a wide lack of agreement on the nascent stage of using hydrogen as fuel in vehicles industry because of the difficulty in delivery and storage.By performing technological and economic analysis,this work aims to establish the most feasible hydrogen production pathway for automotives in near future.From the evaluation,processes such as thermal cracking of ammonia and centralized hydrogen production followed by bulk delivery are eliminated while on-site steam reforming of methanol and natural gas are the most technologically feasible options.These two processes are further evaluated by comprehensive economic analysis.The results showed that the steam reforming(SR) of natural gas has a shorter payback time and a higher return on investment(ROI) and internal rate of return(IRR).Sensitivity analysis has also been constructed to evaluate the impact of variables like NG feedstock price,capital of investment and operating capacity factor on the overall production cost of hydrogen.Based on this study,natural gas is prompted to be the most economically and technologically available raw material for short-term hydrogen production before the transition to renewable energy source such as solar energy,biomass and wind power.

Influence of the synthesis method parameters used to prepare nickel-based catalysts on the catalytic performance for the glycerol steam reforming reaction

The influence of the synthesis method parameters used to prepare nickel-based catalysts on the catalytic performance for the glycerol steam reforming reaction was studied.A series of Al2O3-supported Ni catalysts were synthesized,with nickel loading of 8 wt%,using the incipient wetness,wet impregnation,and modified equilibrium deposition filtration methods.The catalysts＇ surface and bulk properties were determined by inductively coupled plasma（ICP）,N2 adsorption-desorption isotherms（BET）,X-ray diffraction（XRD）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,and temperature-programmed reduction（TPR）.Used catalysts were characterized by techniques such as elemental analysis and SEM in order to determine the level of carbon that was deposited and catalyst morphology.The results indicated that the synthesis method affected the textural,structural and surface properties of the catalysts,differentiating the dispersion and the kind of nickel species on alumina＇s surface.The formation of nickel aluminate phases was confirmed by the XRD and TPR analysis and the β-peak of the Ni/Al-edf catalyst was higher than in the other two catalysts,indicating that the nickel aluminate species of this catalyst were more reducible.Both Ni/Al-wet and Ni/Al-edf catalysts showed increasing CO2 selectivities and approximately constant CO selectivities for temperatures above 550℃,indicating that these catalysts successfully catalyze the water gas shift reaction.It was also confirmed that the Ni/Al-edf catalyst had the highest values for glycerol to gaseous products conversion,hydrogen yield,allyl alcohol,acetaldehyde,and acetic acid selectivities at 650℃ and the lowest carbon deposition of the catalysts tested.The correlation of the catalysts＇ structural properties,dispersion and reducibility with catalytic performance reveals that the EDF method can provide catalysts with higher specific surface area and active phase＇s dispersion,that are easier to reduce,more active and selective to hydrogen production,and more resistant to carbon deposition.

Gas separation using sol–gel derived microporous zirconia membranes with high hydrothermal stability

A microporous zirconia membrane with hydrogen permeance about 5 × 10-8mol·m-2·s-1·Pa-1, H2/CO2 permselectivity of ca. 14, and excellent hydrothermal stability under steam pressure of 100 k Pa was fabricated via polymeric sol–gel process. The effect of calcination temperature on single gas permeance of sol–gel derived zirconia membranes was investigated. Zirconia membranes calcined at 350 °C and 400 °C showed similar single gas permeance, with permselectivities of hydrogen towards other gases, such as oxygen, nitrogen, methane, and sulfur hexa fluoride, around Knudsen values. A much lower CO2permeance（3.7 × 10-9mol·m-2·s-1·Pa-1）was observed due to the interaction between CO2 molecules and pore wall of membrane. Higher calcination temperature, 500 °C, led to the formation of mesoporous structure and, hence, the membrane lost its molecular sieving property towards hydrogen and carbon dioxide. The stability of zirconia membrane in the presence of hot steam was also investigated. Exposed to 100 k Pa steam for 400 h, the membrane performance kept unchanged in comparison with freshly prepared one, with hydrogen and carbon dioxide permeances of 4.7 × 10-8and ~ 3 × 10-9mol·m-2·s-1·Pa-1, respectively. Both H2 and CO2permeances of the zirconia membrane decreased with exposure time to 100 k Pa steam. With a total exposure time of 1250 h, the membrane presented hydrogen permeance of 2.4 × 10-8mol·m-2·s-1·Pa-1and H2/CO2 permselectivity of 28, indicating that the membrane retains its microporous structure.

Genesis of H-ZSM-11 Acidity under Hydrogen and Water Vapor Treatment

1. Introduction Zeolites are widely used in acid heterogeneous catalysis [1, 2]. Due to the unique physical and chemical properties ofzeolites, they are widely used in commercial catalytic processes, such as fluidized catalytic cracking, hydrocracking, methanol conversion to gasoline or olefins, ethylbenzene production, xylene isomerization, aromatics hydrogenation [3-9]. Acidity, high thermal stability, and shape selectivity determine the use of zeolites as catalysts in reaction processes through acid mechanisms [ 10].