摘要
世界大多数天然气气田都含有单质汞和汞的化合物,天然气中的汞含量一般在1μg/m3～200μg/m3。在天然气液化、凝液回收等低温系统中,汞不仅会腐蚀铝制的板翅式换热器,还将导致天然气化工中的贵金属催化剂中毒。目前,天然气脱汞主要采用化学吸附工艺,该工艺在天然气脱汞装置中得到了广泛应用,其脱汞深度可达0.01μg/m3。本文分析了化学吸附工艺的脱汞原理、脱汞剂特性和应用以及影响脱汞效率的因素。通过对载硫/银活性炭、载银分子筛和专用脱汞剂等主要脱汞剂的特性进行分析与对比,提出了主要脱汞剂的适用条件。对于不同用途和不同处理工艺的天然气,其汞含量的限值要求也是不同的。从环保、安全等因素考虑,推荐商品管输天然气中汞含量小于28μg/m3,要求天然气液化及天然气凝液回收等装置中原料气的汞含量小于0.01μg/m3。
Most of natural gas fields all over the world contain elemental mercury and organic mercury compounds,and the mercury concentrations in natural gas is generally 1μg/m3～200μg/m3. In low temperature systems,such asnatural gas liquefaction and NGL recovery,etc.,the mercury in natural gas will not only corrode aluminum-madeplate-fin heat exchanger,but also poison the noble metalcatalysts in the natural gas chemical industry process. Currently,the main technologies of mercury removal from natural gas are chemical adsorption,low temperature separation,etc. Chemical adsorption is better than other mercury removal technologies in its economy,mercury removal effectiveness and environmental protection. By using thisprocess,the mercury content of the natural gas can be reduced below 0. 01μg/m3. This paper analyzes the removing mercury principle of chemical adsorption,characteristics,application and influencing factors of the mercury removal efficiency. By analysis of the main adsorbents,this paperstudies the application conditions for sulfur/silver-impregnated activated carbon adsorbents,containing silver zeoliteadsorbents and special mercury removal adsorbents. Thelimits requirements of mercury in natural gas are different for various usages and processing. On the consideration ofenvironmental protec.safety and other factors,this paper recommends that the mercury concentration in commercial natural gas under pipeline conditions is less than 28μg/m3 ,and the mercury concentration of feed gas in natural gaslique faction and NGL recovery plant is less than 0.01μg/m3,
出处
《石油与天然气化工》
CAS
CSCD
2011年第1期26-31,46,共7页
Chemical engineering of oil & gas
关键词
天然气
脱汞
工艺
吸附剂
汞含量限值
natural gas
mercury removal
technology
adsorbent
limited value of mercury concentration
