关键词: 热煤气, 硫化氢, 类水滑石, 吸附, 氧化锌脱硫剂

Abstract: A zinc-based (cobalt or nickel doped) composite metal oxide derived from a hydrotalcite-like structure with a sheet-like stacked structure was synthesized by the co-precipitation method and used for medium and high temperature gas desulfurization. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the phase composition and morphology of the sorbents and their precursors. It is found that the main crystal phase of the desulfurizer with nickel (or cobalt) doping is still zinc oxide with hexagonal wurtzite structure, and the introduction of nickel (or cobalt) does not significantly change morphology structure of the zinc-aluminum composite oxide and its precursor. The vulcanization and regeneration behavior of the desulfurizer was studied on the fixed bed evaluation device. The results shows that when the molar ratio of zinc to nickel (or cobalt) is 20, the corresponding doped desulfurizer has the longest breakthrough time (324min) and the highest sulfur capacity (25.4%). Compared with the undoped desulfurizer, the optimal regeneration temperature of the sorbent doped with nickel (or cobalt) is reduced by about 60℃. After the introduction of nickel (or cobalt), the desulfurizer not only maintains a high sulfur capacity during multiple desulfurization-regeneration cycles, but also has a sheet-like structure, indicating enhanced desulfurization-regeneration stability of sorbents.

Key words: hot coal gas, hydrogen sulfide, hydrotalcite-like compounds, adsorption, zinc oxide sorbent