System and method for detecting fluid mixture

Patent metadata

Field	Value
Publication number	US-12510517-B2
Application number	US-202318506428-A
Country	US
Kind code	B2
Filing date	Nov 10, 2023
Priority date	Nov 11, 2022
Publication date	Dec 30, 2025
Grant date	Dec 30, 2025

Abstract

A system and method for detecting a fluid mixture are provided. The system includes a pipeline assembly, a first valve, a gas chromatograph and a vacuum pump. The pipeline assembly includes a first pipeline and a second pipeline. The first valve is connected to the first pipeline and controls a flow of the fluid mixture obtained from a reaction in a reactor. The gas chromatograph is provided with a sample injection end and a sample output end, where the sample injection end is connected to an end of the first pipeline away from the first valve; and the sample output end is connected to the second pipeline. The vacuum pump is connected to an end of the second pipeline away from the gas chromatograph.

First claim

What is claimed is:

1 . A method for detecting a fluid mixture by a detection system, wherein the detection system comprises:
a pipeline assembly, comprising a first pipeline and a second pipeline; a first valve, directly connected to an entrance to the first pipeline and controlling a flow of the fluid mixture obtained from a reaction in a reactor; a gas chromatograph, provided with a sample injection end connected to an end of the first pipeline away from the first valve and a sample output end connected to the second pipeline; a vacuum pump, connected to an end of the second pipeline away from the gas chromatograph; and a pulse power supply configured to output a pulse signal having a pulse width less than 10 ms, wherein the pulse power supply is connected to the first valve; wherein the method comprises: turning-off the first valve; vacuuming the first pipeline, the gas chromatograph, and the second pipeline with the vacuum pump; flashing the fluid mixture into a gas mixture at the entrance to the first pipeline by turning-on and turning-off the first valve alternately at a frequency of 1-10 Hz with the pulse signal; and detecting the gas mixture with the gas chromatograph online.

2 . The method of claim 1 , wherein the detection system further comprises:
a first pressure sensor, arranged at the first pipeline and located between the first valve and the gas chromatograph; and a second pressure sensor, arranged at the second pipeline and located between the vacuum pump and the gas chromatograph; wherein the first pressure sensor and the second pressure sensor respectively arranged at the sample injection end and the sample output end of the gas chromatograph; wherein after vacuuming the first pipeline, the gas chromatograph, and the second pipeline with the vacuum pump, the method further comprises: monitoring a pressure value in the pipeline assembly by the first pressure sensor and the second pressure sensor.

3 . The method of claim 2 , wherein the detection system further comprises:
a third pipeline, having a first end connected to the first pipeline and a second end connected to the second pipeline; and a third valve, arranged at the third pipeline; wherein during vacuuming the first pipeline, the gas chromatograph, and the second pipeline with the vacuum pump, the method further comprises: turning on the third valve to reduce the pressure value in the pipeline assembly.

4 . The method of claim 2 , wherein detecting the gas mixture with the gas chromatograph online further comprises:
monitoring the pressure values upstream and downstream of the gas chromatograph achieving balance by the first pressure sensor and the second pressure sensor; and detecting the gas mixture with the gas chromatograph online.

5 . The method of claim 3 , wherein the detection system further comprises an additional heating element arranged at the first pressure sensor, the second pressure sensor, the third valve and the third pipeline;
wherein the method further comprises: heating respective surfaces of the first pressure sensor, the second pressure sensor, the third valve and the third pipeline by the additional heating element to a set preheating temperature; and maintaining the temperature constant.

6 . The method of claim 1 , wherein the detection system further comprises:
a second valve, arranged at the second pipeline and located between the vacuum pump and the gas chromatograph; and a heating element, arranged at the first valve, the pipeline assembly, the gas chromatograph, and the second valve to heat their respective surfaces in contact with the fluid mixture; wherein the method further comprises: heating respective surfaces of the first valve, the pipeline assembly, the gas chromatograph and the second valve by the heating element to a set preheating temperature; and maintaining the temperature constant.

7 . The method of claim 6 , wherein turning-on and turning-off the first valve alternately further comprises:
keeping the vacuum pump operating; and adjusting a threshold pressure of the second valve to be lower than a saturated vapor pressure of a component with a highest boiling point in the fluid mixture, driving the first valve to turn-on and turn-off alternately.

8 . The method of claim 6 , wherein the second valve is a one-way valve with a flow direction from the gas chromatograph to the vacuum pump along the second pipeline.

9 . The method of claim 1 , wherein the detection system further comprises:
a syringe, having a first end inserted into the reactor and a second end connected to the first valve; and a cooler, sleeving around the syringe; wherein before turning-on and turning-off the first valve alternately, the method further comprises: cooling the fluid mixture to a temperature of 473K or below by the cooler.

10 . The method of claim 1 , wherein the gas chromatograph is provided with at least two channels for synchronous analysis of different components, and two ends of each channel are connected to the first pipeline and the second pipeline respectively;
wherein detecting the gas mixture with the gas chromatograph online further comprises: analyzing the different components with different boiling points in the fluid mixture synchronously in respective channels of the gas chromatograph.

11 . The method of claim 10 , wherein the gas chromatograph is provided with three channels equipped with a gas chromatography-mass spectrometry-hydrogen ion flame detector, a gas chromatography-hydrogen ion flame detector, and a gas chromatography-thermal conductivity detector respectively for synchronous analysis of different components.

12 . The method of claim 10 , wherein the at least two channels each are further equipped with an identical volumetric apparatus;
wherein detecting the gas mixture with the gas chromatograph online further comprises: injecting the gas mixture into respective channels from the identical volumetric apparatus; and analyzing the different components with different boiling points in the fluid mixture synchronously in respective channels of the gas chromatograph.

Assignees

• Univ Tsinghua

Inventors

• Jiang Peixue
• Zhu Yinhai
• Wang Yusen

Classifications

• G01N2030/025

  Gas chromatography · CPC title

• G01N30/78

  using more than one detector · CPC title

• G01N30/20

  using a sampling valve · CPC title

• G01N30/06

  Preparation · CPC title

• G01N30/32 Primary

  of pressure or speed (G01N30/36 takes precedence) · CPC title