汞对焦炉煤气液化制LNG工艺的危害及脱除实践

Harm of Mercury on the Liquefaction Process of Converting Coke Oven Gas to LNG and Its Removal Practice

焦炉煤气中的汞会对焦炉煤气液化制LNG装置和LNG产品产生危害。分析了汞对深冷液化装置的危害机理,介绍了某公司采用浸硫活性炭作为脱汞剂,对焦炉煤气中汞的脱除工艺及运行实践。结果表明：汞对铝制LNG装置的主要危害是产生液态金属脆化腐蚀作用;在2.7 MPa、35℃~45℃下,Φ3 mm的脱汞剂对焦炉煤气中的汞脱除率为99.9%,脱汞后的焦炉煤气中汞质量浓度在0.01μg/m3以下,可满足焦炉煤气液化制LNG装置对汞含量的控制要求。

The mercury in the coke oven gas will harm the unit that converts coke oven gas to LNG and LNG product.This paper has analyzed the mechanism of mercury harming the liquefaction unit, and introduced the mercury removal technology and operation practice with the sulfur impregnated activated carbon as the mercury remover applied in a company.The results show that mercury can corrode the aluminum-made LNG unit. The mercury remover with Φ3 mm can remove99.9% of mercury from the coke oven gas under the condition of 2.7 MPa and 35 ℃-45 ℃. The average mercury content is under 0.01μg/m3 in the treated coke oven gas, which can meet the mercury content control requirement of the liquefaction unit converting coke oven gas to LNG.