Morphology-Based Kinetic Study of the Formation of Carbon Dioxide Hydrates with Promoters
Nan Xu, Yu Liu, Zucheng Cheng, Sijia Wang, Lanlan Jiang, Yongchen Song
Abstract
Carbon dioxide (CO2) hydrate is a novel technology for CO2 capture and storage. To achieve more economical and efficient hydrate formation, we investigated the formation of CO2 hydrate with tetrahydrofuran (THF) and sodium dodecyl sulfate (SDS) by using CCD technology. A series of experiments were carried out to investigate the effects of mixed additives under moderate operating conditions, which can provide a safe, low-cost alternative for CO2 storage. Only two kinds of hydrate with flocculent-shaped and dendritic-shaped morphologies are observed, depending on the thermodynamic conditions of the system. The results show that the combination of 3.0 mol % THF + 500 ppm of SDS resulted in a shorter induction time and better CO2 consumption, with hydrate growth along the reactor wall, compared with 3.0 mol % THF alone, due to the possible synergy resulting from simultaneous use of these additives. However, this advantage is weakened with increasing THF concentration (5.56 mol % THF + 500 ppm of SDS), although higher concentrations of THF better expand the hydrate stabilization region.