新型太阳能制氢系统的分析与研究进展

本文对太阳能分解水制氢系统进行了理论和应用方面的分析,重点介绍了光解水的光热电化学分析。对近几年利用太阳能光解水制氢的进展进行了概述,并指出了它们目前存在的缺点。介绍了通过光热化学循环进行太阳能分解水制氢的新途径,并对未来的研究方向进行了展望。     

太阳能制氢技术

氢能是一种高效、无污染的新能源，利用可再生能源制氢是开发氢能源的有效途径。文章总结了国内外目前利用太阳能制氢技术的发展现状，介绍了利用光伏系统转化的电能电解水制氢和利用太阳能的热化学反应循环制氢2种清洁无污染的制氢工艺。     

LSPR效应增强的太阳能光热化学分解水制氢

制备大小2种尺寸Au负载的TiO2样品(分别记为LAuP25和SAuP25)用于太阳能光热化学循环分解水.全光谱下LAuP25和SAuP25的氢气产量分别为9.90和12.60μmol/g,可见光下产量分别为3.91和1.15μmol/g.通过透射电子显微镜(TEM)、X射线能量色散谱(EDS)和X射线衍射技术(XRD...     

太阳能制氢技术

近几年来，随着质子交换膜氢燃料电池技术获得前所未有的进展，氢燃料电池被视为最具潜力的环保汽车动力源，逐步走向商品化。氢燃料电池是利用氢和氧（或空气）直接经电化学反应产生电能。氢也可以直接燃烧放热。氢的热值（１４２０００kJ／kg）是石油热值（４８０００kJ／kg）的３倍。而且，氢的燃烧产物主要是水，具有无污染、无毒等环保优势，是矿物燃料无法比拟的。此外，科学家研究表明，在石油中加入５％的氢，可提高效率２０％，并减少９０％的致癌物；若用管道传送氢气到五六百公里外，要比电线输送同等能量的电力便宜九成。科学…     

太阳能制氢

太阳能制氢江涛美国加州洪堡州立大学沙茨能源研究中心开发的太阳能制氢系统，每天可自动生产出干净的氢燃料。该系统于１０８９年开始筹建，由沙茨通用塑料制造公司Ｂｇ。系统如国１所示。光伏阵列为９．２千峰瓦，Ｓ７．２图】沙茨太阳能恻ｇｇ统、间良多千瓦（电）双极...     

太阳能制氢

氢是我们目前了解到的自然界中最理想的燃料。氢燃烧产生水,对环境不造成任何污染,不影响大自然的生态平衡,是一种“干净”的燃料。氢可以长期储存,也可以远距离运输,因此可以在荒漠地区集中生产,输送到其它地方使用。氢的热值高,可以作为发动机的燃料,替代石油。所以,科学家们对氢燃料抱有特别大的期望。虽然氢燃料具有上述那么多优点,但它却不象煤、石油和天然气那样,可以从地下开采得到。在自然界中,氢已和氧化合成水。人们要得到氢,必须从水中进行分解。例如,工业上常采用电解水制氢,也可以采用煤、石油等常规燃料燃烧所产生的热去分解水制氢,     

用半导体隔片电化学光生伏打电池光解水制氢

过去的十余年间,人们对人工光合作用进行了大量的研究。人工光合作用从广义上讲,就是如何实现太阳能的光化学转换与贮存。换句话说,人们要了解光生电子在绿色植物的光合作用中是如何转移的,并因此而建立一个完全是人工的体系,以模仿自然的光合作用。     

太阳能制氢关键技术研究

围绕太阳能制氢技术展开论述,首先,介绍太阳能制氢技术的研究现状;其次,对于太阳能制氢技术尤其是光催化制氢技术及热化学循环分解水制氢技术,分别从技术原理、关键材料、技术难点等方面进行详细的论述;最后,对太阳能制氢技术研究给出结论及建议,旨在为未来太阳能制氢技术的研发布局和产业技术突破提供参考和思路。     

上海太阳能技术发展现状及其应用前景

简要介绍了上海的太阳能资源条件,分析了太阳能转换利用的主要技术途径,对上海太阳能技术发展现状和应用前景做了总结。     

太阳能热化学制氢技术研究进展

总结了目前国内外太阳能制氢方法的研究现状,经过分析比较,确定太阳能热化学制氢具有极大的潜在发展空间.同时详细介绍了该方法的最新进展,对该方法研究中存在的问题提出了合理的改进建议.     

3D numerical investigation of ZnO/Zn hydrolysis for hydrogen production

The current research is focused on the hydrogen production through a two‐step ZnO/Zn thermochemical water splitting cycle. In the present paper, numerical modeling of the second step is conducted using Computational Fluid Dynamics (CFD)2, where steam reacts with zinc to produce hydrogen. The parametric study shows that the hydrogen yield is relatively insensitive to the steam/zinc molar ratio and inversely proportional to the argon/steam molar ratio. For large argon to steam molar ratios, hydrogen yield is relatively insensitive to the inlet temperature of zinc and steam, and increases marginally with an increase in the argon inlet temperature. Five different reactor configurations were evaluated comprehensively. Among all configurations, a cylindrical reactor with a tangential inlet for argon and zinc, and a radial inlet for steam (both in the bottom plane of the reactor) and a tangential outlet in the top plane of the reactor produced the highest hydrogen yield of 88%. Copyright © 2013 John Wiley & Sons, Ltd.     

A comprehensive comparative energy and exergy analysis in solar based hydrogen production systems

In the presented paper, energy and exergy analysis is performed for thermochemical hydrogen (H₂) production facility based on solar power. Thermal power used in thermochemical cycles and electricity production is obtained from concentrated solar power systems. In order to investigate the effect of thermochemical cycles on hydrogen production, three different cycles which are low temperature Mg–Cl, H₂SO₄ and UT-3 cycles are compared. Reheat-regenerative Rankine and recompression S–CO₂ Brayton power cycles are considered to supply electricity needed in the Mg–Cl and H₂SO₄ thermochemical cycles. Furthermore, the effects of instant solar radiation and concentration ratio on the system performance are investigated. The integration of S–CO₂ Brayton power cycle instead of reheat-regenerative Rankine enhances the system performance. The maximum exergy efficiency which is obtained in the system with Mg–Cl thermochemical and recompression S–CO₂ Brayton power cycles is 27%. Although the energy and exergy efficiencies decrease with the increase of the solar radiation, they increase with the increase of the concentration ratio. The highest exergy destruction occurred in the solar energy unit.     

Photo-electro-chemical chlorination of cuprous chloride with hydrochloric acid for hydrogen production

In this paper, a new photochemical cell is developed and analyzed for copper disproportionation within the Cu–Cl water splitting cycle. In the disproportionation step, cuprous chloride reacts with hydrochloric acid to generate cupric chloride and hydrogen gas. In past literature, it has been demonstrated that this reaction can be conducted electrochemically at 24 bars and 100 °C. This reaction is attractive because it generates compressed hydrogen. Consequently, the work required to compress hydrogen from standard pressure – to 350 bars for example – reduces approximately by 95%. To conduct this reaction electrochemically, the process requires electricity input. Rather than using an external supply, the method proposed in this paper drives the reaction 2CuCl(aq) + 2HCl(aq) → 2CuCl₂(aq) + H₂(g) with photonic energy derived from solar radiation. The photochemical cell comprises one photochemical and one electrochemical reactor separated by a proton conducting membrane. The electrochemical reactor is a half electrolysis cell where CuCl liquid is disproportionated with hydrochloric acid by releasing protons, according to 2CuCl(aq) + 2HCl(g) → 2CuCl₂(aq) + 2H⁺ + 2e⁻. The electrons are transferred to the second reactor by an electron-conducting media, consisting of electrodes and an external circuit. In the photochemical reactor, there are supramolecular complexes dissolved in dimethylformamide that generate multi-electrons at active sites under the influence of solar radiation and catalyze water reduction according to 2H₂O + 2e⁻ → H₂(g) + 2OH⁻. Gaseous hydrogen is collected from above the second reactor, while hydroxyl ions combine with the protons that cross the PEM to supply water according to 2OH⁻ + 2H⁺ → 2H₂O. The overall process is assisted electrically by a dye sensitized solar cell. An optical system including solar concentration, spectral splitting and an optical fibre is developed for enhanced solar energy absorption to supply thermally and electrically the Cu–Cl cycle with energy input. This paper examines the feasibility and expected efficiency of the photochemical disproportionation cell and describes the potential benefits of the thermo-photochemical water splitting process, in contrast to conventional thermochemical water splitting.     

Investigation of solar energy utilization for production of hydrogen and sustainable chemical fertilizer: A case study

Renewable energies play a vital role in the economic and social development and progress of many countries. As one of the most significant sources of renewable energy, solar energy has been used due to its availability in many regions. Generating electricity for hydrogen production is one of the applications of solar energy. In petrochemical complexes, hydrogen is often used for producing fertilizers, especially urea fertilizers. The present study aims at investigating five major Iranian petrochemical complexes in terms of their suitability for the construction of a solar plant to produce electrolysis‐based green chemical fertilizers. To this end, a multicriteria decision‐making model is proposed, which includes the fuzzy analytic hierarchy process (AHP) and extended TODIM method of multicriteria decision making (including crisp, interval, and fuzzy numbers). The present research investigates 10 criteria for prioritizing petrochemical complexes, classified into four general categories, namely, climatic, geographic, environmental, and probability of natural disaster occurrence categories. Having calculated the weight of the criteria using the fuzzy AHP method, the alternatives are prioritized using the extended TODIM method. The methods of simple additive weighting (SAW), Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), and VIKOR were then used for validation of the results. Results showed that the Shiraz Petrochemical Complex has the highest priority and Khorasan Petrochemical Complex has the lowest priority for producing green fertilizer via solar energy–assisted water electrolysis. By using the solar system, Shiraz Petrochemical Complex can emit over 1900 tons less pollutants in the environment per day and provides up to 8% of its annual total production through clean energy.     

Revisiting solar hydrogen production through photovoltaic-electrocatalytic and photoelectrochemical water splitting

Photoelectrochemical (PEC) water splitting is regarded as a promising way for solar hydrogen production, while the fast development of photovoltaic-electrolysis (PV-EC) has pushed PEC research into an embarrassed situation. In this paper, a comparison of PEC and PV-EC in terms of efficiency, cost, and stability is conducted and briefly discussed. It is suggested that the PEC should target on high solar-to-hydrogen efficiency based on cheap semiconductors in order to maintain its role in the technological race of sustainable hydrogen production.     

Research progress of solar thermochemical energy storage

Solar thermal power generation technology has great significance to alleviate global energy shortage and improve the environment. Solar energy must be stored to provide a continuous supply because of the intermittent and instability nature of solar energy. Thermochemical storage (TCS) is very attractive for high‐temperature heat storage in the solar power generation because of its high energy density and negligible heat loss. To further understand and develop TCS systems, comprehensive analyses and studies are very necessary. The basic principle and main components of a solar TCS system are described in this paper. Besides, recent progress and existing problems of several promising reaction systems are introduced. Further research directions are pointed out considering the technical, economic, and environmental issues that existed in the wide application of TCS. Copyright © 2014 John Wiley & Sons, Ltd.     

Techno economic feasibility study on hydrogen production using concentrating solar thermal technology in India

The techno-economic analysis of hydrogen (H₂) production using concentrating solar thermal (CST) technologies is performed in this study. Two distinct hydrogen production methods, namely: a) thermochemical water splitting [model 1] and b) solid oxide electrolysers [model 2], are modeled by considering the total heat requirement and supplied from a central tower system located in Jaisalmer, India. The hourly simulated thermal energy obtained from the 10 MW_th central tower system is fed as an input to both these hydrogen production systems for estimating the hourly hydrogen production rate. The results revealed that these models yield hydrogen at a rate of 31.46 kg/h and 25.2 kg/h respectively for model 1 and model 2. Further, the Levelized cost of hydrogen (LCoH) for model 1 and model 2 is estimated as ranging from $ 8.23 and $ 14.25/kg of H₂ and $ 9.04 and $ 19.24/kg, respectively, for different scenarios. Overall, the present work displays a different outlook on real-time hydrogen production possibilities and necessary inclusions to be followed for future hydrogen plants in India. The details of the improvisation and possibilities to improve the LCoH are also discussed in this study.