Combined hydrogen and oxygen transport ceramic membranes for methane dehydro-aromatisation

在高温(500℃以上)下经济高效地分离高纯度氢气是许多工业过程中的重要步骤，如甲烷重整、生物质气化等。氢传输膜非常适合此类操作，因为它们可以为氢的传输提供高选择性，当与催化膜反应器中的适当催化剂结合时，它们可以在一个过程中将反应和分离步骤结合在一起，从而将整个过程的占地面积、能源、公用事业要求和最终成本降至最低。除了除氢外，对于由于碳沉积而导致催化剂失活的反应，连续和分布式的氧气供应以提供原位催化剂再生将是非常有益的。表现出质子、氧离子和电子导电性的陶瓷膜非常适合于这种应用，并将在甲烷蒸汽重整、甲烷偶联和芳构化等过程中使用。在这个项目中，我们将研究高温陶瓷氢氧传输膜的开发，以用于甲烷芳构化的膜基础上的组合催化剂再生。所使用的膜必须在所需的操作温度和反应条件下具有机械和化学稳定性，以提供对氢渗透的高选择性以及伴随的高氢通量。尽管甲烷作为化学合成的原料具有巨大的潜力，但迄今为止，甲烷最广泛的用途是作为燃料，而作为化学原料的用途主要限于甲烷重整生产合成气和氢气(甲烷重整是迄今为止最成熟的制氢技术)。此外，天然气仍然被浪费地燃烧，导致不必要的温室气体排放，并伴随着资源浪费。在英国的石油平台，天然气燃烧导致的排放量达到每天290万立方米，相当于英国天然气年产量的约3%。人们注意到，与石油生产相关的最大数量的天然气燃烧是缺乏基础设施利用的直接结果。因此，开发一种可行的甲烷利用过程(作为天然气的主要成分)将是非常有益的，特别是在实现英国政府到2050年将二氧化碳排放量减少80%的目标方面。拟议的项目旨在证明基于膜的甲烷芳构化工艺的可行性，为参与国和世界各地的研究界和石油和天然气工业带来重大好处。该项目将材料科学和化学工程的几个方面联系在一起，例如在实际操作条件下的膜稳定性和工业上感兴趣的催化过程的优化，同时努力实现非常有趣的甲烷利用问题的实际解决方案。

The costs-effective separation of high purity hydrogen at high temperatures (above 500 degC) is an important step in many industrial processes such as methane reforming, biomass gasification etc. Hydrogen transport membranes are ideally suited for such operations as they can provide high selectivity towards hydrogen transport and when coupled with appropriate catalysts in a catalytic membrane reactor they can combine the reaction and separation step in one processes thus minimising the overall process footprint, energy, utilities requirements and ultimately cost. In addition to hydrogen removal, for reactions where catalyst deactivation due to carbon deposition is an issue, the continuous and distributed supply of oxygen to provide in situ catalyst regeneration would be highly beneficial. Ceramic membranes that exhibit protonic, oxygen ion and electronic conductivity are ideally suited for such applications and would find use in processes such as methane steam reforming, methane coupling and aromatisation to name but a few. In this project we will investigate the development of high temperature ceramic hydrogen and oxygen transport membranes to be used in membrane-based methane aromatisation with combined catalyst regeneration. The employed membranes must be both mechanically and chemically stable at the required temperature of operation and reaction conditions, providing high selectivity towards hydrogen permeation with concomitant high hydrogen fluxes. Despite the huge potential methane presents as a feedstock material for chemical synthesis, to date the most widespread use of methane is as a fuel, while its use as a chemical feedstock is mainly limited to methane reforming for the production of synthesis gas and hydrogen (methane reforming is the most mature technology to date for the production of hydrogen). In addition, natural gas is still wastefully flared resulting in unnecessary greenhouse emissions with a concomitant resource waste. At UK-based oil platforms emissions due to natural gas flaring amount to 2.9 million cubic meters per day- equivalent to approximately 3% of the yearly total UK gas gas production. It has been noted that the largest amount of gas flared in association with oil production is a direct result of the lack of infrastructure for its utilisation. Therefore, the development of a viable process for utilisation of methane (as the main constituent of natural gas) will be of great benefit, in particular with meeting the UK Government's target of reducing CO2 emissions by 80% by 2050. The proposed project aims to demonstrate the feasibility of a membrane-based methane aromatisation process with significant benefits for the research community and the oil and gas industry both in the participating countries and worldwide. This project links together several aspects of materials science and chemical engineering e.g. membrane stability under real operating conditions and optimisation of a catalytic process of industrial interest, while working towards a practical solution of the very interesting problem of methane utilisation.