甲烷干重整与二氧化碳甲烷化的工艺耦合研究

Study on process coupling between dry reforming of methane and methanation of carbon dioxide

  • 摘要: 甲烷干重整(DRM)与二氧化碳甲烷化(MCD)过程均具有较强的二氧化碳消纳效应,但其单独运行时需要分别消耗大量天然气与氢气,且二者能耗均较高,从而制约了两个工艺的发展与应用,因此探索研究该问题的解决方案对于低碳发展具有重要意义. 本文分析了甲烷干重整与二氧化碳甲烷化两个独立工艺的特点,基于两个反应体系的原料与产物之间可互为利用及二者反应热效应可相互补偿的条件性,初步判断DRM与MCD工艺之间存在质量耦合与热量耦合的可能性. 据此,首次创新性地设计了DRM‒MCD可能的工艺耦合方案,从流程模拟角度证实了工艺耦合的可行性,并分析了不同情形下的耦合特性. 结果表明,随着催化剂技术的发展与进步,DRM与MCD工艺之间可以实现质量、能量的高效双重耦合,耦合工艺具备可显著降低天然气、氢气消耗以及大幅节能降耗的效果,并具有优良的二氧化碳消减与资源化利用效应,且耦合工艺具有灵活的可调节性. 研究结果可为DRM与MCD工艺耦合方案的设计与优化,以及未来该耦合工艺潜在的工程应用价值与可行性研究提供可参考的基础.

     

    Abstract: Both dry reforming of methane (DRM) and methanation of carbon dioxide (MCD) processes offer impressive capabilities for carbon dioxide utilization. However, operating these processes independently involves substantial consumption of natural gas and hydrogen, along with high energy demands, which restrict their broader application. Addressing these challenges is crucial for advancing low-carbon development. This work analyzes the characteristics of two independent processes, namely DRM and MCD. It explores the potential for mass and heat coupling between them, considering the complementary nature of their feedstocks, products, and thermal effects. This investigation leads to the innovative proposal of process coupling schemes for DRM and MCD, marking a pioneering step in this research area. The feasibility of such coupling is assessed through process simulations, examining the characteristics under different situations. The results show that advancements in catalyst technology could enable efficient dual coupling of the DRM and MCD processes in terms of both quality and energy. This coupling process significantly reduces the consumption of natural gas and hydrogen, offering substantial energy savings. In addition, it demonstrates excellent carbon dioxide elimination and utilization capabilities, with the added benefit of flexible adjustability. A key highlight of the DRM‒MCD coupling process is its high mass integration efficiency. Methane produced in the MCD process can serve as a feedstock for DRM, addressing natural gas shortages. Similarly, hydrogen generated by DRM can feed into the MCD, potentially reducing hydrogen usage by at least 26% and mitigating hydrogen resource constraints. Moreover, the coupled process has excellent energy integration. The heat from the exothermic MCD system can be transferred to the endothermic DRM system, leading to significant reductions in energy consumption. When compared to operating the DRM and MCD processes separately, the coupled process could lower total energy consumption by at least 44% and 28%, respectively. This work provides valuable insights for the design and optimization of DRM and MCD process coupling. It underscores the potential engineering applications and feasibility of this approach, contributing to the goal of achieving carbon neutrality by transforming conventional energy and chemical processes.

     

/

返回文章
返回