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

目前，氢（H2）主要来自化石燃料，化石燃料不仅是不可再生资源，而且还会造成温室气体排放。另外，将生物基燃料（如乙醇和甘油）转化为氢气有可能提供长期的能源供应解决方案。在这些燃料中，甘油因其丰富、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。产自生物柴油的粗甘油含有盐、水、醇和游离脂肪酸等杂质。其中一些杂质的存在会在重整过程中引起严重的焦化和性能下降。将甘油气相重整为H2的方法有蒸汽、部分氧化和自热重整（ATR）。甘油的蒸汽重整在文献中得到了广泛的研究。然而，催化剂失活、焦化和H2产率降低仍然是主要的挑战。贵金属基催化剂具有较高的抗焦化性能，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引起了人们极大的兴趣。此外，据报道，加入氧气和使用高蒸汽碳比将减少炭的形成。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在以前的文献中尚未报道。本研究的总体目标是开发一种高性能稳定的镍基催化剂，用于粗甘油ATR高效制氢。这将把甘油从低价值的副产品转化为有价值的制氢生物原料。此外，开发的催化剂将使甘油在更低的温度下转化，这意味着可以使用更便宜的材料来建造，从而大大降低资本成本。总的来说，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.