Hydrate-based hydrogen purification from simulated syngas with synergic additives

• DOI: 10.1016/j.ijhydene.2015.12.065
• Publication Date: 2016-01-04T06:59:41Z
• Authors: Zhiming Xia; Xiaosen Li; Zhaoyang Chen; Kefeng Yan; Chungang Xu; Jing Cai
• Keywords: Technology; Energy & Fuels; CLATHRATE HYDRATE; 02 engineering and technology; PRE-COMBUSTION CAPTURE; Electrochemistry; Physical; Synergic Additive; FIXED-BED REACTOR; CO2 CAPTURE; 0204 chemical engineering; Purification; Science & Technology; RESEARCH PROGRESS; 660; FUEL GAS-MIXTURE; CARBON-DIOXIDE CAPTURE; METHANE SEPARATION; Syngas; 540; PHASE-EQUILIBRIUM; 6. Clean water; Gas Hydrate; BUTYL AMMONIUM BROMIDE; Chemistry; Physical Sciences; Hydrogen

Abstract Hydrated-based separation process has recently raised as a novel technology for hydrogen (H2) purification from mixture gases containing carbon dioxide (CO2). However, the practical application requires suitable hydrate formation condition, hydrate formation rate, gas selectivity, gas storage capacity and so on. This work presents the effect of synergic additives on the hydrate-based syngas purification process based on the thermodynamic, kinetic, purification characteristic studies as well as microcosmic structure analysis. The synergic additives comprise traditional hydrate promoter (tetra-n-butyl ammonium bromide, TBAB) and gas solvent (dimethyl sulfoxide, DMSO). 40.2 mol% CO2/H2 binary mixtures were selected as the simulated syngas. The results show that the synergic additives (TBAB-DMSO) can reduce the equilibrium hydrate formation pressure of the simulated syngas by 80%. Compared to single TBAB for the hydrate-based purification process, the synergic additives could improve the gas consumption rate of the unit system, gas storage capability and gas selectivity by about 32%, 105% and 51% respectively, and decrease the loss ratio of H2 by 1.45%. The Raman analysis reveals that the simulated syngas forms semiclathrate framework with TBAB-DMSO. DMSO only performs as a gas solvent during the gas dissolution and diffusion process, and not participates in the hydrate framework formation.