基于两相流的膜吸收法海水烟气脱硫强化集成及机理研究

Membrane absorption seawater flue gas desulfurization is a perspective technology in solving sulfur dioxide pollution and promoting seawater direct utilization technology. However, there are several bottlenecks in mass transfer enhancement, process integration and membrane scaling control, which hinder its further application. A novel membrane absorption technology based on two-phase flow was proposed. The air bubbles will be introduced to the liquid phase where a two-phase flow would be formed. The mass transfer efficient would be increased and the absorption and oxidation would also be integrated in one component, due to the promotion of the absorption reaction and the enhancement of the fluid turbulence near membrane surface. The transport process accompanied with reaction will be investigated. And both the fluid mechanics status and reaction mechanism will also be simulated. The mass transfer process will also be modeled. The mechanism of two-phase flow on the gas-liquid mass transfer, chemical reaction and seawater oxidation & neutralization will be obtained based on above results. The scaling mechanism under an effect of bubble will be studied, based on which the prevention and washing methods will be proposed and investigated. A novel intensified and integrated seawater flue gas desulfurization process would be formed based on the research work in this proposal, which would enlarge the absorption efficient and promote the application of membrane absorption in flue gas desulfurization.

膜吸收法海水烟气脱硫在解决二氧化硫污染，促进海水直接利用方面极具应用前景，但在传质强化、过程集成及膜表面结垢控制等方面存在诸多问题，制约其应用，亟待解决。基于此，本项目首次提出基于两相流原理的膜吸收海水烟气脱硫的方法，通过在液相吸收侧引入空气相，从改善膜表面流体流动状态和促进氧化吸收反应两方面提高传质效率，并实现吸收脱硫与水质恢复在同一单元内的耦合集成。项目以两相流膜吸收这一伴有化学反应的过程传递研究为基础，结合流体流动模拟及化学反应机制研究，建立针对性的传递模型，揭示两相流在强化传质、水质恢复中的规律及机理；探讨膜表面结垢的形成及曝气的作用，据此提出预防及清洗措施。通过本项目的实施，可深入理解并掌握两相流的膜吸收法海水烟气脱硫基础性规律及机理，有望形成一种新型的膜吸收海水烟气脱硫强化集成方法，对解决膜吸收技术应用瓶颈，促进膜技术在海水烟气脱硫领域的应用具有重要的理论意义与实际价值。

膜吸收法海水烟气脱硫技术在解决二氧化硫污染，促进海水直接利用，节能降耗等方面极具应用前景。为进一步提升其传质效率，过程的集成性，本项目首次提出基于两相流原理的膜吸收海水烟气脱硫的方法，并对其开展研究工作。研究内容主要包括两相流强化膜吸收海水烟气脱硫过程重要影响因素及规律，两相流膜吸收法气泡在强化过程中的物理与化学作用机制，两相流过程膜表面结垢及对膜表面性能的影响，以及相应体系相图开展基础性研究工作。通过本项目的研究，结果表明两相流膜吸收过程在脱硫效率、传质系数等方面相较于普通膜吸收过程均具有一定程度的提高；气泡强化主要源于强化湍流与促进反应的相互耦合，其中前者通过流体力学模拟表明为气泡的扰动作用，后者则是由于氧气在其中的重要作用；膜表面性质及结垢表征、相图研究的结果亦表明亚硫酸钙及氧化产物硫酸钙在膜表面结垢的可能性。通过本项目的开展，探索了两相流膜吸收过程这一新型吸收过程在烟气脱硫中应用的可行性和基础规律，探明物理强化与化学促进在其中作用机制，并获得结垢基础数据，为本技术的进一步应用奠定基础。