Development of absorbent materials in ammonia synthesis

哈伯工艺目前用于生产氨，氨是化肥工业的重要原料，养活了世界48%的人口。然而，高温和高压是必要的，并且需要许多循环步骤，这意味着它是一种能源密集型和昂贵的工艺，只能大规模地可行。如果氨可以在温和的条件下生产，这将是非常有益的。这将创造小规模氨生产的可能性，这将允许在使用点生产肥料。较低的温度和压力意味着该系统可以由可再生能源供电，如风能或太阳能。这将该过程从环境不友好的过程改变为无碳排放的过程。这种远离化石燃料的运动既经济又环保。在温和条件下实现氨生产的一种可能方法是使用吸收剂。所产生的氨被吸收并因此从反应中除去，这迫使平衡朝向产生更多产物。尽管条件不太有利，但这给出了更高的氨产率。在开发新的吸收剂时，将考虑许多因素。吸收剂必须具有高的氨容量。作为固定应用的目标，体积容量是最重要的，尽管良好的重量容量将是有益的。还必须考虑氨吸收剂相互作用的强度。这应该足够强，以确保平衡被转移，但不能太强，使去除氨困难。另一个考虑因素是氨扩散通过吸收剂的能力。氨必须能够容易地穿过孔隙，以确保实现最大容量。该项目的主要目的是更好地了解氨与吸收剂的相互作用，从而开发用于氨生产的新型氨吸收剂。许多新的研究方法将用于实现这些目标。将使用多种合成方法来制备吸收剂。将利用各种表征，包括一些新的技术。人们还希望同步加速器实验能提供有关氨分子在吸收剂中如何排列的新信息。NEXAFS还将用于了解吸收剂中的键合及其对氨储存机制的影响。该项目福尔斯EPSRC物理科学研究领域，由西门子共同资助。

The Haber process is currently used to produce ammonia, an essential feedstock for the fertilizer industry that feeds 48% of the world's population. However, high temperatures and pressure are necessary and many recycle steps are needed meaning it is an energy intensive and expensive process that can only feasibly occur on a large scale.It would be of great benefit if ammonia could be produced under milder conditions. This would create the possibility of smaller scale ammonia production, which would allow fertilizers to be produced at point of use. Lower temperature and pressures mean that it is feasible that the system could be powered by renewable energy, such as wind or solar power. This changes the process from an environmentally unfriendly process to one that is carbon emission free. This movement away from fossil fuels is both economic and environmentally friendly. One possible method of achieving ammonia production at mild conditions is the use of absorbents. The produced ammonia is absorbed and so removed from the reaction, which forces the equilibrium towards producing more products. This gives higher yields of ammonia despite the less favorable conditions. There are a number of factors that will be considered when developing the new absorbent. The absorbent must have a high ammonia capacity. As stationary applications are being targeted, capacity by volume is most important although good capacity by weight would be beneficial. The strength of the ammonia absorbent interaction must also be considered. This should be strong enough to ensure equilibrium is shifted but not so strong as to make removing the ammonia difficult. Another consideration is the ability of the ammonia to diffuse through the absorbent. It must be possible for the ammonia to travel through the pores easily to ensure the maximum capacity is achieved. The main aims of the project are a greater understanding of how ammonia interacts with an absorbent leading to development of a new ammonia absorbent for use in ammonia production. Many novel research methods will be used in achieving these aims. A variety of syntheses will be used to prepare the absorbents. Varied characterization will be utilized including a number of novel techniques. It is also hoped that synchrotron experiments will give new information about how the ammonia molecules order within the absorbents. NEXAFS will also be used to understand the bonding in the absorbent and the effect this has on the ammonia storage mechanism.This project falls within the EPSRC Physical Sciences research area and is jointly funded by Siemens.