Hydrogen generation from biomass derived glycerol using sorption enhanced reaction processes

这项研究旨在开发一种利用吸附强化水蒸气重整的概念，将生物质甘油转化为氢气并同时捕获碳的技术。欧盟目前每年生产约68亿升生物柴油，粗甘油产量约为68万吨。虽然粗甘油的一小部分被提纯用于制药和食品，但大部分被作为废物处理。随着未来生物柴油产量的增加，废甘油的数量肯定会带来很大的挑战。已发表的甘油制氢过程的文献中没有一篇报道甘油转化率和氢气选择性高的组合，这可能会减少对提纯阶段的需求。该方法的创新之处在于利用就地脱除二氧化碳和异地再生二氧化碳吸附剂，从而实现了反应器的连续运行，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，并强化了反应器内的传热。技术挑战包括：(I)实现可控的吸附颗粒流动，使其能够与当地的二氧化碳吸附需求相匹配；(Ii)克服吸附剂和催化剂颗粒之间可能存在的相互作用；以及(Iii)优化反应器内和反应器内的换热，以实现最大的热集成。其他挑战包括评估焦油和碳形成的可能性，确定最佳避免它们发生的条件，确定粗甘油中杂质的作用和去向，提供工艺的材料生命周期分析，并对工艺采取绿色工程方法，同时获得高纯度氢气产品。

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.