【作者】 高文学；

【导师】 陈冠益；

【作者基本信息】 天津大学 ， 热能工程， 2006， 硕士

【摘要】 氢是一种清洁能源,它利用后产生的最终产物是水。目前,主要的制氢途径有:电解水制氢,矿物燃料制氢,生物质制氢,其他含氢物质制氢,各种化工过程氢气副产物的回收等几种。由于矿物燃料的储量有限,开采难度和危险性增加,且开采利用过程中伴随着严重的污染问题,作为在应用性质上可与矿物燃料完全互为替代的唯一一种可再生清洁能源,生物质能因此受到特别的关注。我国生物质资源丰富,生物质制氢具有稳定的资源、制氢技术工艺简单、成本较低、能实现CO2零排放等一系列优点,将成为未来氢能源的主要生产手段之一。生物质气化制氢一般采用循环流化床或鼓泡流化床作为气化反应器,催化剂为镍基催化剂或较为便宜的白云石/石灰石等。本课题在分析各种可能的制氢途径基础上,归纳总结了生物质制氢的各种技术并进行了讨论,同时介绍了制氢常用的催化剂。通过对比分析,指出由生物质催化热解-气化进行富氢气体制取是很有发展前景的一种制氢方法。在此基础上,进行了翔实的理论计算和模拟推导及试验系统设计优化,确定了生物质流化床两级制氢综合试验系统的流程和冷、热态试验的方案,并完成了流化床大型试验系统的设计、建造、冷态调试与测试、热态试运行及热态初步试验。该试验系统包括:空气与蒸汽供给系统、循环流化床气化炉、催化重整反应器、冷却与换热系统、数据自动采集和计算机自动控制系统等。形成了完整的流化床制氢试验体系,为课题后续的研究建立了很好的平台。在冷态试验和热态试验中,针对不同粒径和不同静止床高的试验床料,进行了一系列试验,得出各种主要运行参数(如临界流化速度、布风板阻力、床料阻力等)及相关曲线,这些数据参数和关联曲线对实际的热态制氢试验的运行具有重要指导意义。初步的热态制氢试验表明,设计建造的生物质流化床两级制氢综合试验系统可以达到设计目的,并且气化制氢效率和产率比较理想。更多还原

【Abstract】 Hydrogen is a clean and efficient energy carrier and is expected to play an important role in future energy share. The technology for hydrogen production at this stage mainly includes: electrolysis of water, conversion of mineral fuels, conversion of biomass, transformation of other hydrogen-containing materials, and recovery of by-product hydrogen released by chemical-processing industries. Biomass is a renewable and carbon-neutral resource, and also abundant and cheap in the world particularly in China, therefore using biomass to produce hydrogen is foreseen as a very promising way.The thesis summarizes all technical solutions for the production of hydrogen and afterwards illustrates the comparison of those technical solutions in terms of operation, cost, maturity of technology, and process control. The focus is on thermo-chemical conversion of biomass into hydrogen, specializing in concepts of different technical options, use of different catalysts, and technical advantages/disadvantages of those options. In addition, the factors which have the impact on hydrogen yields and concentrations are discussed. This part of work leads to a conclusion that the fast pyrolysis of biomass using fluidised bed reactor to produce intermediates (bio-oils) followed by the catalytic steam reforming process is recommended as a promising way in terms of technical, economic and environmental acceptance.The theoretical calculation of fluidized bed gasifier based on cotton stalk was completed, and based on it the design of a pilot plant which includes a circulating fluidized bed gasifier, a catalytic steam reforming rector, steam and air supply system, 2 stage feeding system, tar sampling and analysis system, gas condensation, gas sampling and analysis, data collection and acquisition, as well as computer-based automatic control system.Using such pilot plant, a series of experiments were carried out inclusive cold test and hot test. During those tests, the critical fluidization velocity, bed pressure profile and pressure drop were obtained referring to different sizes of bed materials and its static height. The temperature profile and preliminary testing results such as gas composition, gas yield were also obtained from hot tests. construction flow ,datum collecting and control strategy of the compositionThe above-mentioned tests indicate that the designed pilot plant can be operated well and is under the expectation for further study in the field of gasification/pyrolysis of biomass to produce hydrogen or other products.更多还原