Natural gas purifying system

Abstract

The invention discloses a natural gas purifying system which comprises an absorption tower, a desorption tower and an amine liquid regeneration device connected to the liquid outlet of the desorption tower. The absorption tower comprises at least two absorption parts for classifying and purifying natural gas. The liquid inlets of the absorption parts are connected to the liquid outlet of the amine liquid regeneration device in parallel. The liquid outlets of the absorption parts are connected to the liquid inlet of the desorption tower in parallel. The gas outlet of each absorption part is connected to the gas inlet of the next absorption part in series. The first absorption part is provided with a natural gas inlet for allowing natural gas to enter the absorption tower. The last absorption part is provided with a natural gas outlet for allowing natural gas to flow out of the absorption tower. According to the natural gas purifying system, at least two purifying procedures are conducted in the absorption tower, so carbon dioxide in natural gas can be removed twice at least and can be effectively removed.

Description

technical field [0001] The invention relates to the field of energy and chemical industry, in particular to a natural gas purification system. Background technique [0002] In chemical plants, the process flow of desulfurization, decarbonization, dehydration, and other purification processes for gaseous natural gas can be found in figure 1 After the natural gas enters the station, it enters the natural gas purification system after pressure regulation and metering. First, the amine liquid is used to absorb and remove sulfur and carbon dioxide in the absorption tower 01. After being cooled by the cooling device 05, the natural gas enters the gas-liquid separator, and then enters the dehydration device 04 After dehydration, enter the next process; the amine liquid first enters the absorption tower 01 to purify the natural gas, and then exits the absorption tower 01 and passes through the analysis tower 02 and the amine liquid regeneration device 03 for recycling. [0003] Whe...

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Problems solved by technology

[0003] When natural gas is purified in this natural gas purification system, the carbon dioxide content can usually be removed from below 3% to at most 50ppm (part per million). However, when the carbon dioxide content in natural gas exceeds 3%, it must be purified by this natural gas purification system After the carbon dioxide content is at most 50ppm, it is extremely difficult

If the carbon dioxide content of natural gas after purification is higher than 50ppm, it is very easy to cause blockage of the subsequent low-temperature system, and the entire system cannot operate. It may be necessary to start and stop the system frequently, which increases equipment operating costs and seriously affects the efficiency of chemical plants.

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