A method for thawing and cold start-up of a CO cryogenic separation device

Abstract

The invention discloses a method for thawing and cold-state start-up of a CO cryogenic separation system device. Specifically, after the system process gas is degassed, all the liquid in the high-pressure syngas separator and the medium-pressure syngas separator is discharged into the CO / N along the process pipeline. 2 In the tower separation tower, close the valves of each process pipeline; use CO / N 2 The compressor provides a large flow of nitrogen for thawing to the CO cryogenic separation system. According to the flow direction of the process gas, it enters the cooler, condenser, high-pressure synthesis gas separator, medium-pressure synthesis gas separator and liquid CO container for thawing; after thawing Carry out a cold drive, and the gas connection can be performed after the drive is completed. This method has a short thawing time and does not require CO / N 2 The compressor stops, and at the same time, by saving the residual liquid in the system, the discharge of liquid nitrogen in the system is avoided, and most of the cooling capacity is reserved for the start-up of the system after thawing, which shortens the start-up time; the efficiency of thawing and start-up is high, and resource consumption is reduced. The environmental pollution caused by the discharge of raw materials is avoided, and the invention has good social and economic benefits.

Description

technical field [0001] The invention belongs to the technical field of cryogenic separation, that is, low-temperature rectification. It specifically relates to the CO cryogenic separation system, the pipeline thawing of the CO cryogenic separation system and the start-up method in the cold state of the system. Background technique [0002] The cryogenic separation method (also known as cryogenic distillation method) uses mechanical means to compress and cool the gas, and then uses the difference in the boiling point of the gas to rectify the gas to separate different gases. In the process of rectifying the gas, the method firstly needs a large amount of cold energy provided by the outside to liquefy the gas, and then re-separate the various media through heat exchange. [0003] During the operation of the device, when the gas enters the equipment at low temperature (about -145°C), the high boiling point gas is easy to solidify and cause blockage to the equipment; equipment ...

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Problems solved by technology

[0006] The technical problem addressed by the present invention is: after the prior art system degasses, the CO / N 2 The compressor needs to be shut down; and the thawing time after the shutdown is long (up to 72 hours), and the amount of low-pressure nitrogen required for thawing is relatively large; after the system is started up after thawing, a large amount of liquid nitrogen needs to be added to the system before the process gas is introduced. The system cools down and builds the liquid level; the whole process from thawing to starting up has a large amount of emptying, resulting in serious waste of materials

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