二氧化碳水合物在沉积物中的形成过程研究

As a novel oceanic carbon dioxide sequestration method, burying carbon dioxide in ocean sediments by hydrate formation has high safety, good stability and large storage capacity, which shows great potential in carbon dioxide sequestration. This project aims to provide an effective solution to inhibit carbon dioxide diffusion and promote hydrate formation in sediments. Thus, kinetics of carbon dioxide hydrate formation in brine-bearing sediments will be studied systematically. The macroscopic influencing factors including temperature, pressure, salt concentration and porosity of sediments on the diffusion rate of carbon dioxide will be measured in a high pressure reactor and relevant diffusion kinetic models will be established. Microscopically, the hydrate growth and aggregation form will be observed by Raman spectroscopy, scanning electron microscope and optical microscope. Accordingly, the primary factors affecting the hydrate formation can be obtained. The growth mechanism of carbon dioxide hydrate can also be revealed, which provides the basic data and theoretical foundation for the development and applications of hydrate-based carbon dioxide sequestration.

将二氧化碳以水合物的形式埋藏于海底沉积物中是一种新型的海洋封存二氧化碳技术，具有封存量大、安全性高、稳定性好的特点，是一种极具应用潜力的二氧化碳封存技术。本项目为了确定抑制二氧化碳在沉积物中扩散并促进水合物生成的有效途径，将对含盐条件下二氧化碳水合物在沉积物中的形成动力学过程进行系统的实验研究，采用高压反应釜装置综合考察温度、压力、盐浓度以及沉积物中孔隙率和水饱和度等宏观因素对二氧化碳在沉积物中扩散速率和水合物形成速率的影响并建立相关扩散动力学模型，利用拉曼光谱、扫描电子显微镜和光学显微镜等微观测量技术观察水合物晶体在沉积物层中的生长速率和聚集形式，对影响水合物在沉积物中形成的主要因素进行分析，揭示二氧化碳水合物在沉积物层中的生长机理，为水合物法封存二氧化碳技术的发展与应用提供基础数据和理论依据。