Development of nickel based catalyst for the production of renewable hydrogen by autothermal reforming of crude glycerol

目前，氢气（H2）主要由化石燃料生产，化石燃料不仅是不可再生资源，而且还导致温室气体排放。或者，将生物基燃料（例如乙醇和甘油）转化为H2具有提供长期能量供应解决方案的潜力。在这些燃料中，甘油由于其丰富、高能量密度、易于运输以及从环境负担转变为最终价值产品的可能性而受到特别关注。来自生物柴油生产的粗甘油含有杂质，如盐、水、醇和游离脂肪酸。这些杂质中的一些的存在可在重整过程期间引起严重的焦化和性能衰减。甘油气相重整为H2的选择是蒸汽、部分氧化和自热重整（ATR）。甘油的蒸汽重整在文献中已经被广泛研究。然而，催化剂失活、结焦和降低的H2产率仍然是主要的挑战。基于贵金属的催化剂表现出高的抗焦化性，但价格昂贵。镍基催化剂更便宜，但也表现出与贵金属基催化剂相当的活性。因此，开发一种稳定的镍基催化剂用于粗甘油重整反应成为人们极大的兴趣。此外，据报道，添加氧气和使用高的蒸汽与碳的比例将使焦炭的形成最小化。此外，甘油的蒸汽重整是吸热的，而甘油的ATR是放热的（即不需要外部能量输入）。然而，甘油在活性镍基催化剂上的ATR以前在文献中还没有报道。本研究的总体目标是开发一种用于粗甘油ATR高效制氢的镍基高性能稳定催化剂。这将使甘油从低价值的副产物转化为有价值的H2生产生物原料。此外，所开发的催化剂将使甘油在较低温度下转化，这意味着可以使用更便宜的材料进行建造，从而导致低得多的资本成本。总体而言，本研究将通过解决甘油过剩问题使生物柴油的广泛生产成为可能，并提高生物柴油生产的经济性。

At present, hydrogen (H2) is produced largely from fossil fuels which are not only non-renewable resources but also contribute to greenhouse gas emissions. Alternatively, the conversion of bio-based fuels (e.g. ethanol and glycerol) to H2 has the potential to provide a long term energy supply solution. Among these fuels, glycerol is of particular interest due to its abundance, high energy density, ease to transport, and the possibility to change from an environmental burden to end value product. Crude glycerol from biodiesel production contains impurities such salts, water, alcohol, and free fatty acids. The presence of some of these impurities can cause severe coking and performance decay during the reforming process. The options for gas phase reforming of glycerol to H2 are steam, partial oxidation, and autothermal reforming (ATR). The steam reforming of glycerol has been widely investigated in the literature. However, catalyst deactivation, coking and reduced H2 yield remain a major challenge. Noble metal-based catalysts demonstrate high resistance to coking but are expensive. Ni-based catalysts are cheaper but also exhibit comparable activity with noble metal-based catalysts. Hence, the great interest in the development of a stable Ni-based catalysts for the crude glycerol reforming. Also, it has been reported that adding oxygen and the use of high steam to carbon ratio would minimize char formation. Further, steam reforming of glycerol is endothermic whereas ATR of glycerol is exothermic (i.e. require no external energy input). However, ATR of glycerol over active Ni-based catalysts has not been reported before in the literature. The overall objective of this research is to develop a Ni-based high performance stable catalyst for the efficient production of H2 by the ATR of crude glycerol. This will covert glycerol from a low value byproduct to a valuable H2 production bio-feedstock. Also, the developed catalysts will enable glycerol conversion at lower temperatures implying that cheaper material can be used for construction thereby resulting in much lower capital costs. Overall, this research will enable the widespread production of biodiesel by solving the glycerol glut problem, and improve the economics of biodiesel production.