Electrolytic Silicon and Iron Powders as Alternatives to Hydrogen as Energy Carrier and Store

电解硅粉和铁粉作为氢的替代品作为能量载体和储存

• 批准号: EP/F026412/1
• 负责人: George Chen
• 金额: $ 19.36万
• 依托单位: University of Nottingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF026412%2F1
• 关键词: Electrolytic; Silicon; Iron; Powders; Alternatives

The hydrogen technology is at present regarded as a potential solution to the problems resulting from using fossil fuels, particularly CO2 emission. However, the development of the hydrogen technology has encountered a number of difficulties, of which the need to reversibly store the hydrogen gas is a major challenge. Particularly, the reversible storage capacities achievable even in the best materials or devices are too low, for example, LaNi5H6 (< 1.5 wt%, ~300K) and high pressure or liquid hydrogen tank (< 4 wt%), but the high storage capacity in some others, e.g. NaAlH4 (> 7 wt%, >520K) and LiBH4 (>18.4 wt%, >553K), does not allow convenient reuse of the stored hydrogen.In fact, hydrogen gas is not an energy source because it does not exist in nature. In any energy application, the hydrogen gas only plays the roles of the energy store when the hydrogen gas is produced using another form of energy, such as electricity from the renewable or nuclear energy, and of the energy carrier when the gas is combusted in an internal combustion engine or fed into a fuel cell. These two roles of hydrogen can be well played by other pure elemental substances, such as silicon and iron. Like hydrogen, the energy stored in silicon and iron can be released through a chemical or an electrochemical reaction with oxygen. The products from these reactions, i.e. silicon and iron oxides, are the natural components of the Earth and will have zero environmental impact. One of the reasons why hydrogen has been so far the research and public focus is its high specific energy (energy per unit mass). Unfortunately, hydrogen is a gas under ambient conditions and the need for storage by any known method significantly reduces hydrogen's real specific energy. For example, the specific heat from the combustion of hydrogen gas in air is 122.8 kJ/g (425 degC), but it reduces to 30.7 kJ/g when hydrogen is stored at 25wt% (the theoretical maximum hydrogen storage capacity), but to a disappointing low value of 8.0 kJ/g when hydrogen is stored at 6.5 wt% (the targeted reversible hydrogen storage capacity of the US Department of Energy). On the contrast, iron and silicon are stable solids under ambient conditions and there is no storage problem. For combustion in air, the specific heat of silicon is 32.4 kJ/g and that of iron is 7.3 kJ/g. The other consideration for energy application is the energy density (energy per unit volume). Using the mass density of the three elements, it can be shown that, again for combustion in air, the heat density is only 8.6 kJ/cm3 for liquid hydrogen, but 75.5 kJ/cm3 for silicon and 57.5 kJ/cm3 for iron. Therefore, silicon and iron are thermodynamically better than hydrogen when storage is considered. On the technical side, the combustion of silicon and iron powders has long been proven in research, and it is now the time to develop a technique in which silicon and iron powders can be produced easily using renewable energy, particularly solar energy. This proposed research aims to experimentally demonstrate the thermodynamically predicted feasibility of using silicon and iron powders as the alternatives to hydrogen as the energy store and carrier. Particularly, it is intended to produce and regenerate the silicon and iron powders from their oxides using molten salt electrolysis under solar energy workable conditions (electricity and heat). The applicant and co-workers have already performed preliminary tests and produced successfully fine silicon and iron powders using the novel FFC Cambridge Process (co-invented by the applicant in the UK) at relatively high temperatures (800 degC ~ 900 degC). It is intended to lower the molten salt temperatures in this project (< 500 degC) so that solar heat can be used in the process. The products will be investigated by TG and DSC and tested for combustion in air. The optimal powder particle morphology and its correlation with the electrolysis conditions will be identified

目前，氢技术被视为使用化石燃料，尤其是CO2发射引起的问题的潜在解决方案。但是，氢技术的发展遇到了许多困难，其中需要可逆地存储氢气是一个主要的挑战。特别是，即使在最佳材料或设备中可以实现的可逆存储能力太低，例如LANI5H6（LANI5H6（<1.5 wt％，〜300K），高压或液体氢气罐（<4 wt％），但其他一些人的高存储容量，例如。 NaAlh4（> 7 wt％，> 520k）和libh4（> 18.4 wt％，> 553k）不允许方便地重复使用储存的氢。实际上，氢气不是能源，因为它在自然界中不存在。在任何能源应用中，当使用另一种形式的能量（例如可再生能源或核能的电力）生产氢气时，氢气仅扮演能量储存的作用，当气体在内部燃烧发动机中燃烧或喂入燃料电池时，能量载体的作用。氢的这两个作用可以由其他纯元素物质（例如硅和铁）很好地发挥作用。像氢一样，储存在硅和铁中的能量可以通过化学物质或氧电化学反应释放。这些反应的产物，即硅和氧化铁是地球的天然成分，将对环境影响为零。氢气到目前为止的研究和公众重点是其高特异性能量（每单位质量的能量）的原因之一。不幸的是，氢是在环境条件下的气体，并且需要通过任何已知方法储存的需求显着降低了氢的实际特定能量。例如，空气中氢气中的特定热量为122.8 kJ/g（425度），但是当氢存储在25wt％（理论最大氢存储容量）时，它会减少到30.7 kJ/g，但在6.5 wt forment formess formess forsess forsess forsess forsepsible forsepsible forsepsible（均为8.0 kJ/g）的目标（均为5.0 kJ/g）的目标（均为hyds fords forse forsible）。相反，铁和硅在环境条件下是稳定的固体，没有存储问题。对于空气中的燃烧，硅的比热为32.4 kJ/g，铁的热量为7.3 kJ/g。能源应用的另一个考虑因素是能量密度（单位体积的能量）。使用这三个元素的质量密度，可以证明，对于空气中的燃烧，液态氢的热密度仅为8.6 kJ/cm3，而硅的热量密度为75.5 kj/cm3，铁对铁的热量密度仅为75.5 kJ/cm3。因此，考虑存储时，硅和铁在热力学上比氢更好。在技​​术方面，长期以来在研究中已经证明了硅和铁粉的燃烧，现在是时候开发一种技术，可以使用可再生能源（尤其是太阳能）轻松生产硅和铁粉。这项拟议的研究旨在在实验上证明使用硅和铁粉作为氢作为能量储存的替代品的热力学预测性。特别是，它旨在在太阳能可行条件（电力和热量）下使用熔融盐电解产生和再生其氧化物中的硅和铁粉。申请人和同事已经在相对较高的温度（800摄氏度〜900摄氏度）下，使用新型FFC剑桥工艺（由申请人在英国申请人共同生产）成功制作了硅和铁粉。它旨在降低该项目的熔融盐温度（<500摄氏度），以便在此过程中使用太阳热。 TG和DSC将对产品进行研究，并测试空气中的燃烧。将确定最佳粉末颗粒形态及其与电解条件的相关性

项目成果

Supercapacitor and supercapattery as emerging electrochemical energy stores

• DOI: 10.1080/09506608.2016.1240914
• 发表时间: 2017-01-01
• 期刊: INTERNATIONAL MATERIALS REVIEWS
• 影响因子: 16.1
• 作者: Chen, George Z.

Sustainable Conversion of Carbon Dioxide into Diverse Hydrocarbon Fuels via Molten Salt Electrolysis

• DOI: 10.1021/acssuschemeng.0c08209
• 发表时间: 2020-12
• 期刊: ACS Sustainable Chemistry & Engineering
• 影响因子: 8.4
• 作者: Ossama Al-Juboori;Farooq Sher;S. Rahman;T. Rasheed;G. Chen;G. Chen

Highlights from liquid salts for energy and materials - Faraday Discussion, Ningbo, China, 11-13 May 2016.

• DOI: 10.1039/c6cc90442d
• 发表时间: 2016-10
• 期刊: Chemical communications
• 影响因子: 4.9
• 作者: Bamidele Akinwolemiwa;Linpo Yu;Di Hu;Xianbo Jin;John M. Slattery;G. Chen

Interactions of molten salts with cathode products in the FFC Cambridge Process

• DOI: 10.1007/s12613-020-2202-1
• 发表时间: 2020-12-30
• 期刊: International Journal of Minerals, Metallurgy and Materials
• 作者: Chen GZ

Assessment of toxicity reduction in ZnS substituted CdS:P3HT bulk heterojunction solar cells fabricated using a single-source precursor deposition

• DOI: 10.1039/c9se00123a
• 发表时间: 2019-03
• 期刊: Sustainable Energy & Fuels
• 影响因子: 5.6
• 作者: M. Bishop;M. Tomatis;Wenjun Zhang;C. Peng;G. Chen;Jun He;Di Hu