流化床加压富氧燃烧捕集CO2的关键基础问题

Pressurized oxygen-fuel combustion is a new generation of CO2 capture technology with low energy consumption, as well as one of the most promising carbon capture technologies for commercial applications in coal-fired power plants. Depending on the topic of “solid fuel combustion and its pollution and emission reduction mechanisms” from the Guide to Key Programs of National Natural Science Foundation of China, the current project is proposed to focus on the following key research issues including “Effects of pressure and oxygen concentration on the evolution of carbon component”, “Combustion characteristics and process directional controls”, “Key equipment scale-up and system optimization & integration” and so on. By means of developing various research approaches including the reaction kinetic analysis of fluidization progress, molecular dynamics simulation, “turbulent gas - discrete particles/particle clusters + reaction” simulation etc., the project will emphatically study the pressurized, oxygen-enriched or carbon-rich combustion kinetics of coal particle/particle clusters, the combustion characteristics and the process control mechanisms in pressurized oxygen-enriched fluidized beds, and the integration and scale-up laws of above systems, to finally elaborate the evolution mechanisms of carbon component and the related control methods in the pressurized oxygen-enriched processes. The aim of this project is to develop the theories and methods for pressurized oxygen-enriched fluidized beds to efficiently capture CO2, and boost the frontier science theories and optimization methods of the new carbon capture technology. With more than 30 years of study experience in pressurized fluidized beds from the supporting institution and the solid research foundation in various dense gas-solid reaction systems, the proposer team is capable of acquiring the expected innovative achievements.

加压富氧燃烧是新一代的低能耗CO2捕集技术，也是最具工业化前景的燃煤电站碳捕集技术之一。本项目以“流化床加压富氧燃烧捕集CO2”为研究对象，拟围绕“碳组分演化的压力和氧浓度效应”、“燃烧特性与定向调控方法”、“关键装置放大与系统优化集成”等关键基础问题，在发展流态化反应动力学分析、分子动力学模拟、“湍流—离散颗粒团+化学反应”数值模拟等科学研究方法的基础上，重点开展煤颗粒/群的加压富氧燃烧动力学、流化床的加压富氧燃烧特性与定向调控机制、流化床加压富氧燃烧系统集成放大规律三方面研究内容，阐明流化床加压富氧燃烧过程中碳组分的演化机理和调控方法。本项目旨在发展高效、低能耗CO2捕集的流化床加压富氧燃烧理论与方法，促进新一代碳捕集技术前沿科学理论和设计优化方法的发展。依托单位具有30多年的加压流化床研究积累，申请团队在流化床等稠密气固反应系统的基础研究方面具有良好的基础，有望获得预期创新研究成果。

加压富氧燃烧作为新一代的低能耗CO2捕集技术，也是最具工业化前景的燃煤电站碳捕集技术之一，在运行效率、系统稳定性和经济性等方面具有突出优势。本项目以“流化床加压富氧燃烧捕集CO2”为研究对象，针对碳组分演化的压力和氧浓度效应不明、燃烧特性与定向调控方法研究不足、关键装置放大规律与系统优化集成方法不明等关键基础问题，重点开展煤颗粒群的加压富氧燃烧动力学、流化床的加压富氧燃烧特性与定向调控机制、流化床加压富氧燃烧系统集成放大规律三方面研究内容，阐明流化床加压富氧燃烧过程中碳组分的演化机理和调控方法。取得了以下进展： .建成了一套热输入30kW、压力0.4MPa的加压富氧燃烧实验装置，攻克了加压条件下的流态调控、物料循环、连续加料/排渣等关键技术，完成了实验室验证，出口干烟气CO2浓度达到90vol%以上，并获得了燃烧压力、气氛、氧浓度等对燃烧效率、成灰特性、污染物排放的影响规律。.揭示了煤加压富氧燃烧过程中的碳组分演化规律、CO2生成途径以及压力和O2浓度的影响机制，形成了加压富氧流化床燃烧的理论与方法，为低能耗捕集CO2提供理论依据与实验数据支撑。.建立了关键设备富氧循环流化床的放大设计准则，以及降低CO2捕集能耗的系统集成优化方法，结果显示系统净发电效率在约1MPa时达到最大，为加压流化床富氧燃烧大型工业示范装置的设计和运行提供了坚实的理论和基础数据。