SGER: Catalytic Reforming of Electrically Charged Glycerin Nano-droplets to Produce Hydrogen

提案编号：CBET-0708932主要研究者：Fernando，Sandun D.机构： 密西西比州立大学为了解决目前生物质催化制氢的局限性，将研究一种替代的、创新的范例，其中当带电的粘性液滴直径在1-100 nm之间时，它们将被重整，即纳米相重整。阻碍该技术发展的因素是在带正电荷的基底和带负电荷的催化剂/载体界面处发生的化学反应以及粘性纳米级液滴如何与固体相互作用的知识方面存在差距。将在综合研究中进行实验研究和理论建模和模拟，以了解这种行为，最终目标是提高纳米重整技术。 CO2中性的可再生原材料如脂质、碳水化合物及其衍生物具有高分子量且高粘性，并且现有的制氢技术，即蒸汽重整和水相重整（APR），在重整这些流体方面不是非常有效。然而，APR在几个方面优于蒸汽重整：APR 1）通过节省汽化潜热需要较少的总能量; 2）具有在显著较低的温度下改革的能力和3）具有利用在蒸汽重整温度下被热力学抑制的水煤气变换反应的全部潜力的能力。尽管有上述优点，但主要由于固体（催化剂）层周围的扩散阻力，APR受到缓慢的氢气产生速率的阻碍。蒸汽重整，尽管其在历史上已经从短链烃产生高的氢气产率，但是由于与从液体（液滴100 nm）到气体（颗粒1 nm）的状态改变相关的传质限制，在粘性基质的重整中是无效的。这导致我们提出的研究带电的液体纳米液滴的直径为1至100 nm的催化重整。长期目标是开发一种主要从生物可再生原料生产氢气的重整技术，生物可再生原料具有与石油基碳氢化合物明显不同的理化性质。本申请的目的是提高在接地的Ni/碳-石墨导电催化剂表面上的带正电荷的基质液滴的催化重整中所涉及的化学的基本理解。该研究的中心假设是，与传统的APR工艺相比，重新形成直径在1-100 nm之间的带电底物液滴可以显著增加底物转化率。我们的假设的基本原理和知识价值是，如果反应物分裂成更细的液滴并带电，则反应物密度可以降低，同时允许带正电的反应物液滴被吸引到带负电的催化剂载体上，因此，在催化剂活性位点处的底物可用性比APR高得多。我们已经使用我们的电裂解装置获得了初步数据，证明了从高粘度甘油生产纳米颗粒是可能的。中心假设将通过追求以下具体目标进行测试：1。生产具有一致轮廓的甘油纳米颗粒-输入参数：流体流速、流体密度、自由空间的介电常数、流体的表面张力和电导率特性影响纳米喷雾的液滴尺寸分布。通过改变上述参数，将获得由50 nm直径的液滴组成的液滴尺寸分布。 2.比较氢气选择性、甘油转化率和副产物形成-将测量APR、蒸汽重整和纳米相重整的这些参数，同时在所有实验运行中保持催化剂负载、催化剂表面积和进料流速恒定。 3.借助冷凝物中的产物鉴定提出反应机理-冷凝物的产物将通过GCMS、HPLC和LCMS进行分析，以确定反应机理。将进行量子化学计算，并开发补充模拟，然后进行实验验证，以筛选可能的催化剂。根据这些结果，另一种催化剂可能会被添加到实验设计中，以更准确地评估这一概念。该结果应适用于广泛的其他液体生物产品，如含碳甘油三酯及其衍生物。这项研究可能有助于拓宽未来氢基能源系统的原材料选择。研究将纳入教育，并将培训一名博士生和一名少数民族和代表性不足的学生。

Proposal Number: CBET-0708932Principal Investigator: Fernando, Sandun D. Institution: Mississippi State UniversityIn order to address present limitations of catalytic hydrogen production from biomass, there will be investigated an alternative, innovative paradigm where electrically charged viscous liquid droplets will be reformed when they are between 1-100 nm in diameter, i.e, nanophase reforming. The factors impeding development of this technology are the gap in the knowledge of the chemistry that occurs at the positively charged substrate and the negatively charged catalyst/support interface and how viscous nanoscale droplets interact with solids.Both experimental studies and theoretical modeling and simulation will be conducted in an integrated study to understanding this behavior, with the ultimate goal of enhancing the nanophase reforming technique. Renewable raw materials which are CO2 neutral such as lipids, carbohydrates and their derivatives have high molecular weights and are highly viscous and the existing hydrogen production technologies, i.e, steam reforming and aqueous phase reforming (APR), are not highly effective in reforming such fluids. However, APR is advantageous in several ways over steam reforming: APR 1) requires less overall energy by saving the latent heat of vaporization; 2) has the ability to reform at substantially lower temperatures and 3) has the ability to harness the full potential of the water gas shift reaction which is thermodynamically inhibited at steam reforming temperatures. Despite the above advantages, APR is hindered by slow hydrogen production rates mainly due to diffusion resistance around the solid (catalyst) layer. Steam reforming, although it has historically resulted in high hydrogen yields from short chained hydrocarbons, is ineffective in reforming of viscous substrates due to mass transfer limitations associated with changing the state from a liquid (droplets 100 nm) to a gas (particles 1 nm). This leads to our proposed study of catalytic reforming of charged liquid nanodroplets of 1 to 100 nm in diameter. The long-term goal is to develop a reforming technique to produce hydrogen primarily from biorenewable feedstock which has markedly different physiochemical properties than petroleum based hydrocarbons. The objective of this application is to improve the basic understanding of the chemistries involved in catalytic reforming of positively charged substrate droplets over a grounded Ni/carbon-graphite conducting catalyst surface. The central hypothesis of the study is that reforming electrically charged substrate droplets that are between 1-100 nm in diameter can significantly increase substrate conversion in comparison to the conventional APR process. The rationale and the intellectual merit of our hypotheses is that if the reactants are split into finer droplets and electrically charged, the reactant densities could be reduced while allowing the positively charged reactant droplets to be attracted to the negatively charged catalyst support, thus instigating much higher substrate availability at the catalyst active sites than that of APR. We have obtained preliminary data using our electrosplitting device to demonstrate that the production of nanoparticles from highly viscous glycerin is possible. The central hypothesis will be tested by pursuing the following specific aims: 1. Production of glycerin nanoparticles with a consistent profile - Input parameters: fluid flow rate, fluid density, permittivity of free space, surface tension and conductivity properties of the fluid affect the droplet size distribution of the nanospray. A droplet size distribution that consists of 50 nm diameter droplets will be obtained by changing aforementioned parameters. 2. Comparing the hydrogen selectivity, glycerin conversion and byproduct formation - These parameters will be measured for APR, steam reforming and nanophase reforming while keeping catalyst loading, catalyst surface area and feed flow rates constant through out all experimental runs. 3. Proposing reaction mechanisms with the help of product identification in the condensates - The products of the condensate will be analyzed through GCMS, HPLC and LCMS to determine the reaction mechanisms. Quantum chemical calculations will be performed and complementary simulations developed, followed by experimental validation to screen possible catalysts. Depending on these results, another catalyst might be added into the experimental design for a more accurate evaluation of this concept. The results should be applicable to a broad range of other liquid bio-products, such as carbonaceous triglycerides and their derivatives. This research may help broaden the raw material choices available for future hydrogen based energy systems. Research will be incorporated into education, and one doctoral student and one minority and underrepresented student will be trained.