Natural gas processing system

Abstract

The invention relates to the technical field of liquefied natural gas processing, and concretely discloses a natural gas processing system. The natural gas processing system comprises a LNG storage tank, an absorbing tower, a cooling system connected with the absorbing tower, an amine liquid and flashing steam recovery utilization system; the cooling system comprises a cooler, a heat exchanger, a molecular sieve and a cold box which are connected in order; the amine liquid and flashing steam recovery utilization system comprises an amine liquid flash tank, a separation tank, an amine liquid gathering tank, a lean / rich amine liquid heat exchanger, and an amine liquid regeneration boiler; natural gas from a LNG storage tank flows from the bottom of the absorbing tower from down to up, the amine liquid flowed out of the amine liquid regeneration boiler flows from the top of the absorbing tower, the amine liquid and natural gas enable convection contact, after acidic gas absorbed in natural gas, the amine liquid is introduced into the amine liquid and flashing steam recovery utilization system, and the natural gas after acidity is removed is introduced into the cooling system. The natural gas processing system has the advantages that the natural gas temperature before entering into the cold box is reduced, the consumption of a cold agent is reduced; the flashed combustible gas is recovered, and a purpose of saving energy and reducing consumption is effectively achieved.

Description

technical field [0001] The invention relates to the technical field of liquefied natural gas processing, in particular to a natural gas processing system. Background technique [0002] In the process of natural gas processing, the acid gas must be removed first, and then the gas and amine liquid will be separated. The removal of acid gas requires the use of an amine liquid flash tank. The original process is that the amine liquid absorbs the carbon dioxide in the natural gas and then enters Amine liquid flash tank, in which the amine liquid is flashed, and the flashed gas contains a large amount of methane, and this part of the gas is vented to the flare through the pressure control valve for combustion. A large amount of combustible gas containing methane flashed out of the amine liquid flash tank is directly sent to the torch for combustion, and this part of energy cannot be effectively used, resulting in waste. [0003] The cold box used in the liquefaction of natural ga...

AI Technical Summary

Problems solved by technology

The current equipment makes the temperature of natural gas high before entering the cold box, which can reach up to 46.5°C. After entering the cold box, it needs to consume more refrigerant for heat exchange and cooling to reach -162°C. If the temperature of the natural gas in the tank exceeds 66°C, it will cause chain shutdown of the device

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