Hydrogen generation from biomass derived glycerol using sorption enhanced reaction processes

本研究旨在开发一种技术，利用吸附增强蒸汽重整的概念，将生物质衍生的甘油转化为氢气，同时进行碳捕获。欧盟目前每年生产约68亿升生物柴油，产生约68万吨粗甘油。虽然一小部分粗甘油被纯化用于制药和食品应用，但大部分被视为废物。随着未来生物柴油产量的增加，废弃甘油的数量将是一个很大的挑战。关于从甘油制氢方法的公开文献中没有报道高甘油转化率和高H2选择性的组合，这可以降低对纯化阶段的要求。所提出的方法的新奇在于使用CO2的原位去除和CO2吸附剂的非原位再生，从而使得反应器能够连续操作，在反应器压力下直接输送氢气，使用相对低容量的吸附剂，向反应器引入更多的物理热，和强化反应器内的热传递。技术挑战包括（i）实现吸附剂颗粒的受控流动，使得它们可以与CO2吸附的局部需求相匹配，（ii）克服吸附剂和催化剂颗粒之间可能的相互作用，和（iii）优化向反应器和在反应器内的热传递以获得最大的热集成。其他挑战包括评估焦油和碳形成的可能性，并确定最佳避免其发生的条件，确定粗甘油中杂质的作用和命运，提供该工艺的材料生命周期分析，并在获得高纯度H2产品的同时对该工艺采取绿色工程方法。

This research aims towards developing a technology that converts biomass derived glycerol to hydrogen with simultaneous carbon capture, using the concept of sorption enhanced steam reforming. EU currently produces approximately 6.8 billion litres of biodiesel per annum, which yields ~0.68 million tons of crude glycerol. Although a small portion of the crude glycerol is purified for pharmaceutical and food applications, the majority of it is taken as waste. With an increase in the biodiesel production in the future, the amount of waste glycerol will certainly present a big challenge. None of the published literature on hydrogen production processes from glycerol reports a combination of high glycerol conversion and high H2 selectivity, which could reduce the requirements for the purification stage. The novelty of the proposed approach is the use of in-situ removal of CO2 and ex-situ regeneration of CO2 adsorbent, thus enabling a continuous operation of the reactor, direct delivery of hydrogen at the reactor pressure, the use of relatively low capacity adsorbent, introduction of more physical heat to the reactor, and intensification of heat transfer within the reactor.The technological challenges include (i) achieve the controlled flow of adsorbent particles so that they can match with the local demand of CO2 adsorption, (ii) overcoming possible interactions between adsorbent and catalyst particles, and (iii) optimise heat transfer to and within the reactor for maximum heat integration. Other challenges include assessing the potential for tar and carbon formation, and determine the conditions which best avoid their occurrence, determining the role and fate of impurities in the crude glycerol, provide the materials life cycle analysis of the process, and take a green engineering approach to the process while achieving a high purity H2 product.