固体醇燃料的研制

介绍了固体醇燃料的组成、各成分的作用、固体燃料凝胶化形成机理,提出以硝化棉为凝胶剂和以甲醇与乙醇为主要成分制备固体燃料的最适宜配方和制备工艺条件。     

氮肥厂联醇用作醇基燃料获得成功

人民所用燃料是一个国家国民经济和生活水平的重要指标之一。我国人民所用燃料从柴草到煤炭,现在已用上煤气、天然气、液化气等,体现了我国国民经济发展和我国人民生活水平的提高。但我国大部分人口居住在小城镇和广大农村,而煤气、天然气、液化气还不能很快普及推广。为了逐步使我国小城镇和广大农村向现代化方向发展,为他们提供安全可靠和保护环境的清洁燃料,成为广大科技工作和企业家的关注目标,其中甲醇被作为首选对象之一。     

调整汽车燃料结构，发展醇燃料汽车

我国石油资源短缺和大气质量下降问题正日益引起人们的关切。在新世纪，我国需要调整汽车能源结构，改变以石油为唯一能源的局面，发展清洁的石油代用燃料汽车，改善大气质量。介绍了主要洁净代用燃料的物化特性、应用情况和存在问题。特别对甲醇燃料汽车发展现状、排放性能、使用情况和其前景作了介绍、分析比较，认为从资源、环境、经济、实用、方便和能源安全考虑，煤制甲醇是很良适合我国国情并极有前景的洁净代用燃料。     

醇基燃料的发展与应用

醇基燃料是以甲醇等醇类物质为主体原料并掺杂少量扩散剂、稳定剂等添加剂的新型环保燃料。本文综述了醇基燃料的发展和应用,并对醇基燃料的发展进行展望。     

浅谈固体酸催化一步法制备松油醇

本文介绍了固体酸催化一步法制备松油醇的试制工作,并对试验结果进行了讨论。一、前言松油醇是合成香料中产量较大的品种,广泛应用于日用化学品、有机溶剂、消毒杀菌剂、印染助剂等方面。     

凝胶燃料的制备

介绍了酒清、汽油及其混合物等液体燃料的固化方法，制备条件和测试结果。     

固体燃料的生产工艺

论述了一种新型固体燃料的生产工艺，对比了不同工艺方法制备固体燃料的特点。讨论了不同原料的影响因素，实验表明选择硬脂酸作凝胶剂、氢氧化物作固化剂制备的固体燃料具有安全、无毒、价廉、使用方便等优点。     

Biodiesel formulations as fuel for internally reforming solid oxide fuel cell

Biodiesel (alkyl ester of rapeseed oil) is prepared using various, methyl, ethyl and butyl alcohols through the transesterification process. Sodium hydroxide and sulfuric acid are used as catalyst for methyl alcohol, ethyl alcohol and butyl alcohol respectively. Biodiesel-water formulations are formulated using water and emulsifiers like sodium lauryl sulphate (SLS) and SPAN 80 in a high shear mixer. The formulations are tested at 800 °C as fuel for internal reforming in solid oxide fuel cells (SOFCs). The formulations based on methyl and butyl esters require the use of emulsifiers to prepare stable emulsions, while ethyl esters are able to form stable emulsions without emulsifiers. The decrease in the biodiesel concentration of formulation does not have any effect on the power density of the ethyl ester formulation. Fuel cells fuelled with 20% formulations lasted longer than 50% formulations in all the formulations tested as result of increase in steam carbon ratio resulting in effective removal of carbon deposited on the anode surface. Butyl ester formulations exhibited the worst performance in both types of formulation tests. The best performance was exhibited by 20% ethyl formulation in terms of life of the cell but 50% methyl ester formulations exhibit the highest power density.     

Electrocatalysis for the direct alcohol fuel cell

The basic principles of a direct alcohol fuel cell are first presented. Low temperature fuel cells (working between ambient temperature and 80–120 °C) need improved catalysts to reach performance levels sufficient for practical applications, particularly for the electric vehicle and for portable electronic devices. This is the case of proton exchange membrane fuel cells (PEMFC) and of direct alcohol fuel cells (DAFC) for which the kinetics of the electrochemical reactions involved (oxidation of reformate hydrogen containing some traces of carbon monoxide, oxidation of alcohols, reduction of oxygen) is rather slow. Basic understanding of electrocatalysis is then examined, showing how to increase the reaction rate both by the nature and the structure of the catalytic electrode and by the electrode potential. Finally the most used Pt-based electrocatalysts to activate the electrode reactions occurring in a direct ethanol fuel cell (DEFC) are discussed on the basis of electrochemical, spectro-electrochemical and fuel cell experiments.     

Analysis of usability of potato pulp as solid fuel

The paper describes an attempt to analyse the usability of potato pulp as a future ecological solid fuel. The analysis of potato pulp, carried out within the framework of the study, comprised the following aspects: assessing energetic values of potato pulp, assessing the effects of burning solid fuel in the form of pellets made of potato pulp, assessing energy expenditures spent on the process of drying and densification of potato pulp. The performed determination of the elemental composition (chlorine, sodium, potassium, phosphorus and nitrogen), examination of energetic values of potato pulp (the humidity of potato pulp, the heat of combustion, the calorific value, and the ash content), as well as examination of densification (pelletisation) of potato pulp, make it possible to conclude that fuel made of potato pulp, in comparison to other types of biomass, could become a very good and attractive type of boiler fuel, and owing to the fact that it is produced in potato processing plants in great amounts, it could be successfully used by the professional power industry.     

Electrophoretically deposited thin film electrolyte for solid oxide fuel cell

Abstract

Thin films of 8 mol% yttria stabilised zirconia (YSZ) electrolyte have been deposited on non-conducting porous NiO–YSZ anode substrates using electrophoretic deposition (EPD) technique. Deposition of such oxide particulates on non-conducting substrates is made possible by placing a conducting steel plate on the reverse side of the presintered porous substrates. Thickness of the substrates, onto which the deposition has been carried out, varied in the range 0·5–2·0 mm. Dense and uniform YSZ thin films (thickness: 5–20 μm) are obtained after being cofired at 1400°C for 6 h. The thickness of the deposited films is seemed to be increased with increasing porous substrate thickness. Solid oxide fuel cell (SOFC) performance is measured at 800°C using coupon cells with various anode thicknesses. While a peak power density of 1·41 W cm^?2 for the cells with minimum anode thickness of 0·5 mm is achieved, the cell performance decreases with anode thickness.     

Isothermal models for anode-supported tubular solid oxide fuel cells

Modeling of solid oxide fuel cells (SOFCs) has gained considerable significance in recent years. A detailed phenomenological model for SOFC can be used to understand performance limitations, optimization, in situ diagnostics and control. In this paper, we study the transport and various electrochemical phenomena in an anode-supported tubular SOFC using a steady-state model. In particular, we discuss the importance of modeling different phenomena vis-a-vis their impact on the prediction capability of the model. It is observed that even a reasonably simple model can be sufficiently predictive in a particular operating range. As the operating range of the cell is increased, the predictive capability of a model validated in a narrow range cannot be guarantied. It has also been observed that neglecting momentum conservation in the model for a tubular SOFC can affect the predictive capability of the model at higher overpotentials. An extensively validated model is used to study the percentage conversion of oxygen and oxygen concentration profile within a cell at different operating conditions. All of the simulation studies are supported by experimental data that spans a wide range of operation in terms of the DC polarization, reactant flow rates and operating temperatures.     

Effects of solid loading on joining and thermal cycling performance of glass-ceramic sealing pastes for solid oxide fuel cells

The variation of the joining performance of glass-ceramic sealants in the form of a paste as a function of the solid powder content in the sealing paste after the formation and a number of thermal cycles are experimentally studied. Three different sealing pastes having 40, 50 and 60 wt % solid loadings are prepared and tested for this purpose. The pastes are applied between two metallic interconnector plates and subjected to a glass formation step for the joining. The fracture strengths of 24 samples prepared for each case are determined via tensile tests. Similarly, the mechanical performances of the sealants after 3, 6 and 9 thermal cycles are also obtained. The results reveal that the joining strength tends to increase with the amount of solid powder content in the paste. This can be attributed to increased number of crystalline phases in the sealants with increasing the solid loading. The thermal cycles, on the other hand, are shown to have an adverse effect on the joining performance regardless of the solid loading. However, the rate of decrease in the fracture strengths is found to decrease with the solid powder contents in the pastes. This can be elucidated by the amount of glassy phases in the sealants, which can be expected to increase with the solid loading and provide self-healing ability. The microstructures of the fracture surfaces of all samples are also investigated by a scanning electron microscopy. The obtained images confirm the tensile test results.     

固体酒精的可逆溶胶-凝胶过程研究

采用硬脂酸和N aOH为胶凝剂,调节其比例,制备出不同凝固温度的固体酒精。采用体视显微镜、熔点管、黏度计、电导率仪和分光光度计等仪器研究了固体酒精的溶胶-凝胶过程。研究中发现固体酒精为多孔结构,孔径为1~14μm,估计由直径为150nm的溶胶粒子堆积而成;它没有固定“熔点”,在凝胶温度附近其黏度和电导率明显变化。     

Development of La(CrCoFeNi)O3 system perovskites as interconnect and cathode materials for solid oxide fuel cells

The purpose of this research is to develop interconnect and cathode materials for use in solid oxide fuel cells (SOFCs) which demonstrate desired properties of outstanding sintering properties, high electrical conductivity, and excellent chemical stability at high temperatures. Five different perovskite oxides of lanthanum in combination with chromium, iron, cobalt and nickel oxides powders, i.e. LaCr_0.7Co_0.1Fe_0.1Ni_0.1O₃(LCr7CFN), LaCo_0.7Cr_0.1Fe_0.1 Ni_0.1O₃(LCo7CFN), LaFe_0.7Cr_0.1Co_0.1Ni_0.1O₃(LFe7CCN), LaNi_0.7Cr_0.1Co_0.1Fe_0.1O₃(LNi7CCF), and LaCr_0.25Co_0.25Fe_0.25Ni_0.25O₃(LCCFN), were synthesized through the Pechini method. XRD results show that all materials are in single phase, either rhombohedral or orthorhombic crystal structure. The resulting powders were able to be sintered to a high relative density at a temperature of 1400 °C for 2 h in air. The electrical conductivity of the sintered sample was measured and evaluated from 300 °C to 800 °C. The LCCFN sample appears to have the best combination of sintering property (approximate 94% relative density) and electrical conductivity (88.13 Scm⁻¹ at 800 °C).     

Electrospun composite nanofibers for intermediate-temperature solid oxide fuel cell electrodes

Considering the dominant loss associated with surface oxygen exchange reactions among other complex electrochemical processes, the design of an electrode structure for the reasonable operation of solid oxide fuel cells is challenging. The surface oxygen exchange reaction can be considerably facilitated using composite nanofibers containing the electrode, electrolyte, and catalyst. The composite nanofiber electrodes containing Pd show the smallest polarization resistance of 0.031 Ωcm² and the maximum power density of 0.7 W/cm² at 650 °C, which are 39.2% and 12.5% improved values compare to the catalyst-free composite nanofiber electrodes, respectively. These results provide an facile fabrication strategy for developing high-performance electrodes for use in solid oxide fuel cells.