Quality inspection of natural gas in vehicles
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This post was last edited by Yang Qing on 2020-11-5 at 15:03. As part of environmental improvement measures, the company has switched to using natural gas as a fuel source for its boilers and other drying and calcination equipment. Since the installation of the natural gas pipelines is still in progress, the current daily consumption is 1 to 2 trucks’ worth of natural gas, which is then fed into the natural gas storage tank area. Yesterday, the boss suddenly asked me: Can the calorific value of this natural gas be measured? I replied that it is certainly possible to conduct tests; we haven’t dealt with this before, but the natural gas is supplied by a legitimate company (China Resources Gas). You can’t possibly be suspecting that someone is adulterating the natural gas, right? The boss said, \"There’s doubt, but you can’t possibly not be aware of the quality, right?\" I said: The calorific value of natural gas is specified by standards. As for testing, I’ll check it out; I guess equipment for such testing must cost hundreds of thousands of yuan, so I think there’s no need for testing for now. The boss is an amateur; he thinks that everything can be analyzed, so he can’t explain things clearly. With those questions and answers yesterday, he probably got his answer as well: our laboratory’s current equipment is not capable of conducting such tests; therefore, there’s no need to spend money on testing equipment unless it’s necessary. It’s better to allocate limited funds to more useful purposes. The purpose of this discussion post is to ask fellow car owners whether it is necessary to conduct a calorific value test on natural gas used in vehicles.
For vehicles equipped with hydrogen gas, horizontal high-pressure tanks are generally used, and they are of the type designed for four units per vehicle. The determination of the calorific value of natural gas itself is not complicated; the combustion method and calorimeters can be used. Their advantages are high accuracy and ease of operation of the instruments, but they require a large amount of sample. Calculation based on component analysis using chromatography is also a relatively accurate and convenient method, requiring the analyst to have some chemical knowledge. Offline analysis of investments is not very costly, especially for chromatography, as existing laboratory analysis equipment can be utilized. However, since it is high-pressure gas analysis, special attention must be paid to the representativeness of the samples taken and sample contamination during the transfer and injection process; another concern is safety. The boss thinks that anything can be analyzed; there’s nothing wrong with that. Just think about it – we can figure out the composition of the gases in stars that are billions of light-years away, so it’s of course no problem to analyze the natural gas that enters the plant.
Our laboratory is very basic; it only has domestically produced flame atomic absorption and UV-Vis spectrophotometers, as well as one relatively expensive liquid chromatography instrument, so we currently do not have the necessary facilities for testing. During difficult times for the company, it is not recommended to invest in testing equipment just to measure natural gas. It seems correct that anything can be analyzed; for laypeople, it’s enough to give a pill so that its composition can be determined. Western medicine might also be worth trying, but if it’s a blind sample with unknown composition, it may be necessary to go to advanced laboratories and spend a lot of money to conduct the tests; it’s not something that can be done in ordinary laboratories as they think. If it’s an unknown traditional Chinese medicine sample and one wants to study its formula, even the CIA probably wouldn’t be able to do it. I’m going off on a tangent here; this isn’t comparable to the clear requirement of “measuring the calorific value of natural gas”. ;P Thank you, Teacher Q, for your reply. Once the company’s situation improves, it will be necessary to acquire general testing equipment for the laboratory. But given the current situation, where even applying for a domestic-made graphite furnace is difficult, I will not apply for such equipment for now.
As for the necessity of testing the calorific value of natural gas, it generally depends on its intended use. If it is to determine the calorific value, there is a certain necessity for this; of course, it can also be calculated using the data provided by the supplier (by determining the calorific value based on the composition). If it is used as a chemical raw material, the calorific value data is not very necessary, but the composition data may be more meaningful.
All of our company’s natural gas is used as fuel; currently it is supplied in vehicle deliveries and priced based on weight, while in the future it will be supplied via pipelines in the industrial park, with pricing based on standard cubic meters. It depends on the development of the company. Thank you again to Teacher Q for your guidance.