Activated carbon treatment method and method for removing heavy hydrocarbon by natural gas liquefaction adsorption method

Abstract

The invention provides an activated carbon treatment method which comprises the following steps: heating to-be-treated activated carbon to 500-700 DEG C in an inert atmosphere at a heating rate of 3-10 DEG C / min, carrying out heat treatment for 60-150 minutes, conducting cooling to 450-580 DEG C, carrying out heat treatment for 60-150 minutes in a reducing atmosphere, and conducting cooling to room temperature to obtain activated carbon, wherein the air speed of the heat treatment in the inert atmosphere is 200-500 h<-1>, the air speed of the heat treatment in the reducing atmosphere is 200-550 h<-1>, and the ratio of H2 in the reducing atmosphere is 60-100 vol%. By controlling the conditions, the micropore volume of the activated carbon is obviously increased; and the surface acidity of the activated carbon is reduced and the alkalinity is increased. The obtained activated carbon has larger adsorption capacity for deep removal of heavy hydrocarbon in natural gas, and the removal precision of heavy hydrocarbon components which are easy to cause coagulation and blockage meets the requirements of a natural gas liquefaction process.

Description

technical field [0001] The invention belongs to the technical field of activated carbon treatment, and in particular relates to a treatment method of activated carbon and a method for removing heavy hydrocarbons by a natural gas liquefaction adsorption method. Background technique [0002] Liquefied natural gas is to cool natural gas to about -162°C and convert it into a liquid product, which solves the problem of low volumetric energy density of natural gas. [0003] Natural gas except CH 4 In addition to the main component, it may also contain H 2 , CO 2 , H 2 S, N 2 , C 2 h 6 , C 3 h 8 , i-C 4 h 10 , n-C 4 h 10 , Neo-C 5 h 12 (neopentane), i-C 5 h 12 , n-C 5 h 12 , C 6 h 14 , C 7 h 16 , C 6 h 6 , toluene, ethylbenzene, xylene, naphthenes, H 2 O, Hg, etc. Exceeding the standard content of heavy hydrocarbon C5+ components will cause condensation in the cold box during the cryogenic liquefaction stage of natural gas, which will not only seriously aff...

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Problems solved by technology

Since Neo-C 5 h 12 , benzene, cyclohexane, etc. have high saturated vapor pressure and high freezing point. Therefore, the method of low-temperature condensation separation cannot remove these components to a qualified level. When the content of these components is high , in the process of low-temperature freezing and condensation removal, the condensation temperature needs to be reduced to about -65°C or even lower. During the cooling process, the heat exchanger will be blocked and the deheavy hydrocarbons cannot be removed normally.

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