Effects of Composite Accelerators on the Formation of Carbon Dioxide Hydrates

Yingmei Wang; Aili Niu; Shenghao Liu; Ji Chen; Xuemin Zhang; Jing Zhan

doi:10.1021/acsomega.1c06834

Effects of Composite Accelerators on the Formation of Carbon Dioxide Hydrates

ACS Omega. 2022 Apr 29;7(18):15359-15368. doi: 10.1021/acsomega.1c06834. eCollection 2022 May 10.

Authors

Yingmei Wang^{1

2

3}, Aili Niu^{1

2

3}, Shenghao Liu^{1

2

3}, Ji Chen⁴, Xuemin Zhang^{1

2

3}, Jing Zhan⁴

Affiliations

¹ Western China Research Center of Energy & Environment, Lanzhou University of Technology, Lanzhou 730050, China.
² Key Lab of Complementary Energy System of Biomass and Solar Energy, Lanzhou, Gansu Province 730050, China.
³ Collaborative Innovation Center of Key Technology for Northwest Low Carbon Urbanization, Lanzhou 730050, China.
⁴ State Key Laboratory of Frozen Soil Engineering, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.

Abstract

To improve the rate of formation of carbon dioxide hydrates, tetra-n-butylammonium bromide (TBAB) was compounded with different concentrations of sodium dodecyl sulfate (SDS) and nanographite, and the effects of these mixtures on carbon dioxide hydrate formation were studied. The addition of TBAB alone, as well as mixtures of TBAB and SDS or nanographite, shortened the induced nucleation time, and the induction times of the TBAB-2.5 g/L nanographite and TBAB-0.24 g/L SDS systems were the shortest and longest, respectively. Further, on mixing TBAB and SDS, the induced nucleation time first increased and then decreased with the increase in the SDS concentration. When TBAB and nanographite were mixed together, the induced nucleation time first decreased, then increased, and again decreased with the increase in the nanographite concentration. In addition, the hydrate formation rate and conversion were highest for the TBAB-0.48 g/L SDS system and lowest for the TBAB-0.06 g/L SDS system; in the first 35 min, from the end of gas charging, the TBAB-10 g/L nanographite and TBAB-5 g/L nanographite systems yielded the highest and lowest hydrate formation rates and conversions, respectively. For the composite systems, obvious effects were observed in the initial stages of reaction, but the effects varied over the course of the reaction. Overall, the use of different accelerators resulted in little differences in the total production, conversion, and formation rate of carbon dioxide hydrates over the course of the reaction.