Chromatograph and mass spectrometer

Methane chromatography measurement uses hydrogen as the carrier gas, which causes interference with the measurement of hydrogen, carbon monoxide, and carbon dioxide; therefore, these should be measured separately

2# mzhao1981 agrees with you; the price difference between mass spectrometers and chromatographs is too large.

In terms of performance alone, mass spectrometers are definitely superior – there is no signal delay and their accuracy is high. The downside is the high price. It seems that currently, the Texaco furnaces in China are only in use at Weihua, and they are supplied as complete sets by those little Japanese companies. Currently, many Texaco furnaces no longer use chromatography; instead, infrared heating is employed for measurement. This method involves almost no latency, requires less maintenance, and is cheaper than chromatography. It offers better economic performance when used in multi-channel setups.

CNOOC Hainan Jiantao Methanol Company also uses mass spectrometers, and this was asked during the interview. But I haven’t used it at work.

The 800,000-ton methanol project of CNOOC also uses the same mass spectrometer as that in Phase 1 with a capacity of 600,000 tons. :victory: Orders have already started coming in.

Which product is 6# reny_0901 using? Is it from the original American Thermoelectric? We need to use a mass spectrometer here too

Yes. Thank you! So it’s a buddy after all. Hehe. Pick it up – we can’t let such posts sink. Help more people get to know mass spectrometers.

Infrared plus thermal conductivity hydrogen is likely to be superior in terms of cost-effectiveness and ease of use compared to mass spectrometry or chromatography. Mass spectrometry or chromatography requires the use of infrared spectroscopy separately for methane detection; as far as I know, Thermo Electric’s products are quite good in this regard

Thank you, friend upstairs! However, there are still a few points that need to be explained: 1. The price of mass spectrometers is indeed high, but they have multiple analysis pathways and a large number of components. If there are many analysis channels and components in the process flow, the cost naturally decreases. 2. Fast analysis speed, which helps improve process control. (Ethylene oxide SD process designated mass spectrometer) 3. It requires extremely low maintenance and is very simple to use. There is basically nothing that needs maintenance. 4. Good stability. (Many people are worried that with just one instrument, if something goes wrong, then we won’t know anything at all.) In fact, there’s no need to worry; the stability of the instrument is excellent – otherwise it wouldn’t be sold at such a high price. Hehe) 5. Normalize the analyzed data. The problems that often occur with single-table and chromatographic methods during measurement will not arise, and the sum of the measured values will equal 100%. The additional infrared methane analyzer was added because the designers and owners wanted to have a way to monitor the status of the furnace by measuring methane levels, in case there were problems with the mass spectrometer (it’s not that the mass spectrometer cannot measure methane levels). In reality, however, there is no need for this; in actual use, both instruments are kept running, but it doesn’t serve any real purpose. Besides, the gasification state is not monitored solely based on the methane content.

(1) It can be said that chromatographic analysis for methane, hydrogen, CO, and CO2 is feasible, but the analysis has a significant delay of several minutes to ten minutes. Since methane is a very important parameter and poor control of its levels can even lead to explosions, real-time performance is essential; therefore, methane analysis is carried out using a separate analysis channel. Therefore, one chromatograph plus another methane analysis instrument can be chosen (the user has freedom of choice; there are many options available on the market, including laser and infrared types). (2) Mass spectrometry instruments enable rapid analysis of multiple components across multiple channels, making them a good option; however, their successful application in China is still limited. Moreover, an overseas online mass spectrometry analysis system is quite expensive – it refers to an entire system, not just a single mass spectrometer – with prices often ranging from 2 to 3 million yuan, which limits its use.