Abstract:
In order to promote the development of mercury removal technology of natural gas, reduce the cost of mercury removal and master the technology of renewable mercury removal process for natural gas, it is necessary to develop the study and industrial application of renewable mercury removal process for natural gas. Based on the research and development of renewable silver-loaded molecular sieve, the relevant performance parameters of the silver-loaded molecular sieve were obtained through the application evaluation of the regenerated temperature, regenerated repeatability, the adaptability of mercury mass concentration and liquid-containing condition of feed gas, dynamic mercury adsorption capacity and other properties of silver-loaded molecular sieve in laboratory and field equipment. After repeated regeneration at high temperature, the mercury-removing ability of silver-loaded molecular sieve had no obvious decrease, and the reproducibility was good, which could meet the engineering application conditions. The higher the regeneration temperature was, the better the silver-loaded molecular Ag-B regeneration effect was. The lowest regeneration temperature was 280 ℃. The depth of mercury removal was not affected by the mass concentration of mercury in the feed gas. The mercury mass concentration in the product gas was below 0.05 μg/m
3 even if the feed gas was adsorbed by the silver-loaded molecular sieve with different mercury concentrations. The dynamic mercury adsorption capacity of silver-loaded molecular Ag-B was 0.36 mg Hg per 1 g mercury-removing agent. Too large or too small air velocity of the mercury removal tower was not conducive to the adsorption of mercury removal, so it should be maintained within a certain range. The optimal air velocity of empty tower under 10 MPa pressure was 1.5-2.5 m/min. The liquid in feed gas would lead to significant decrease of mercury removal capacity of silver-loaded molecular sieve. Under wet condition, the mercury removal capacity of silver-loaded molecular sieve was about 63% of that under dry gas condition. In practical engineering design, natural gas dehydration should be carried out before mercury removal by silver-loaded molecular sieve. The acquisition of relevant engineering experience and key parameters can provide engineering references for design and operation of other renewable mercury removal facility.