Development and Evaluation of Hydrogen Energy System

氢是未来有吸引力的燃料，因为它作为能量载体的巨大灵活性。它也是一种清洁燃料，不含S，N和C。龟山和吉田提出的UT-3（东京大学）循环由溴、钙和铁化合物组成的四个固气反应组成，已对该循环进行了一系列动力学测量和经济评估，并建造了一座实验室规模的工厂并成功运行，可连续生产氢气。在这些研究中，热源被认为是高温气体反应堆（HTGR）。另一方面，未来太阳能的一个重要用途将是作为生产燃料和化学品过程的热源。太阳能热源与化学过程耦合的方式将强烈影响整个系统的成本和效率。在美国已经进行了太阳能热-化学过程界面的各种研究。 ...更多信息 3循环包括两个在高温下的吸热水解反应。这些反应是热化学循环的一部分，也作为一个热存储系统。基于这一观点，我们共同提出了一个太阳能热化学过程的初步概念设计，该过程使用UT-3循环，生产率为2000 Nm^3/h，并讨论了蒸汽加热器和两个吸热固定床反应器的热性能。该工厂由以下子系统组成：（1）定日镜场子系统，（2）太阳能接收器子系统，（3）使用UT-3循环的热化学氢设备子系统，（4）使用化学热泵的热回收子系统。仿真结果表明，在过渡状态下连续运行的可行性，并表明蒸汽流量的控制是有效的，以补偿传入的太阳能热的变化。水解反应器既可作为太阳能的化学储存系统，又可作为太阳能驱动的热化学循环的组成部分，其制氢成本的初步分析表明，UT-3循环具有很大的潜力，在不久的将来可能成为与太阳能热相结合的有竞争力的过程。少

Hydrogen is an attractive fuel for the future because of its great flexibility as an energy carrier. It is also a clean fuel and does not contain S, N and C. The UT-3 (the University of Tokyo) cycle proposed by Kameyama and Yoshida is composed by for four solid-gas reactions consisting of Br, Ca and Fe compounds.A series of kinetic measurements and economical evaluation have been already conducted for this cycle, and a bench-scale plant was constructed and successfully operated to produce hydrogen continuously. In these studies the heat source was supposed to be a high-temperature gas reactor (HTGR). On the otherhand, an important use of solar energy in the future will be as the heat source for processes which produce fuels and chemicals. The means by which the solar heat source is coupled to the chemical process will strongly influence both the cost and efficiency of the overall system. Various studies of the solar heat-chemical process interface have been conducted in the USA.The UT- … More 3 cycle includes two endothermic hydrolysis reactions at high temperature. These reactions are parts of the thermochemical cycle and also act as a thermal storage system. Based on this view, we did jointly proposed a preliminary conceptual design of a solar thermochemical process using the UT-3 cycle for the production rate of 2000 Nm^3/h, and discusses the thermal performance of the steam heater and two endothermic fixed bed reactors.The plant consists of the following subsystems : (1) Heliostat field subsystem, (2) Solar receiver subsystem, (3) Thermochemical hydrogen plant subsystem using the UT-3 cycle, (4) Heat recovery subsystem using a chemical heat pump. The simulation results demonstrated the feasibility bf continuous operation in the transient state and showed that the control of steam flow rate was effective to compensate for changes of incoming solar heat. It was also shown that the hydrolysis reactors can work well both as a chemical storage system for the solar heat and as the parts of solar driven thermochemical cycle.The preliminary analysis of hydrogen production cost showed that it would be very favourable and that the UT-3 cycle may have a great potential to become a competitive process in combination with solar heat in the near future. Less