为了推动天然气脱汞技术发展,降低脱汞成本,掌握可再生天然气脱汞工艺技术,有必要开展可再生天然气脱汞工艺的研究和应用。在可再生载银分子筛研发基础上,通过可再生天然气脱汞装置设计、建设及运行,实现了可再生脱汞工艺在国内天然气净化处理行业的工业应用。通过对原料气再生和产品气再生两种再生工艺中原料气、产品气、再生气汞浓度的检测和分析,说明可再生脱汞工艺稳定可靠,载银分子筛可将原料气中的汞脱除至0.05 μg/m3以下,完全满足商品天然气汞浓度小于28 μg/m3的指标要求;通过脱水分子筛和载银分子筛进行复配使用,能同时实现脱水脱汞功能;采用原料气作再生气时,应充分考虑再生气中高浓度的汞对载银分子筛装填量的影响;常温下钢材对汞具有一定的吸附作用,应避免常温下含汞再生气进入脱汞塔底部,造成脱汞塔切换运行后产品气汞浓度超标。相关工程经验及关键参数的获取,可为今后设计和运行可再生天然气脱汞装置提供一定的借鉴。

In order to promote the development of mercury removal technology for natural gas, reduce the cost of mercury removal and master the technology of renewable mercury removal from natural gas, it is necessary to launch a study on renewable mercury removal technology and its industrial application. Based on the research and development of renewable silver-loaded molecular sieve, the design, construction and operation of the renewable mercury removal facility are conducted, resulting in the industrial application of renewable mercury removal process in domestic natural gas purification and treatment industry. By monitoring and analyzing the mercury concentration of raw gas, product gas and regenerated gas in two types of regeneration processes, the results show that:1)the renewable mercury removal process is stable and reliable, and the mercury content can be reduced to below 0.05μg/m3in raw gas by using silver-loaded molecular sieve, which fully meets the mercury concentration requirement of commercial natural gas(I. e. less than 28μg/m3); 2)by combining dehydrated zeolite and silver-loaded molecular sieve, dehydration and mercury removal can be achieved simultaneously; 3)the effect of high mercury concentration in the regeneration gas on the loading of the silver-loaded molecular sieve should be fully considered when raw gas is used as the regeneration gas;4)at room temperature, the steel has certain adsorption effect on mercury, so we should avoid letting the mercury-containing regeneration gas enter the bottom of the mercury removal tower at room temperature, as this could result in the mercury vapor concentration of the product gas exceeding the product gas specification after switching operation of the mercury removal tower. The gain in relevant engineering experience and acquisition of key engineering parameters can provide some useful references for design and operation of renewable mercury removal facility in the future.