The strange phenomenon of acetylene purification, please ask an expert to answer it
Thread Content
Our company recently discovered the following strange phenomenon in acetylene purification. I used silver nitrate test paper to test the purified acetylene gas. It showed yellow, but the available chlorine in the purification tower was normal. The quality inspection office analyzed that it did not contain phosphine. What is the reason, or what other impurities caused this strange phenomenon. Thank you all. This post was last edited by shizhiyong001 on 2008-9-23 08:32 ]
It may also contain sulfur and phosphorus, check whether the analysis process is correct.
Is it because the concentration of sodium hypochlorite solution is low and the hydrogen sulfide has not been washed out? :loveliness: :handshake
No, our sodium hypochlorite concentration can only be high or low. It has been close to the limit recently, but there is still such a strange phenomenon. The test paper shows it, but the instrument cannot detect it. It is very strange.
reason: Check the silver nitrate solution to see if it is discolored due to oxidation. Check whether the test paper is contaminated or contaminated with colored substances. Check the concentration of the silver nitrate solution. If it is too high, discoloration may occur. Check the sampling process to see if acetylene gas entrains the sodium hypochlorite solution. The silver nitrate is discolored due to oxidation.
Is the production situation normal? Is there any sulfur and phosphorus substances accumulated in the sampling tube? Check it in multiple rows.
"The concentration of sodium hypochlorite can only be controlled high and not low, and it has been close to the limit recently. This in itself does not mean that it will definitely meet the demand for sodium hypochlorite when sulfur and phosphorus are too high in actual working conditions. On the one hand, the process must meet the requirements of the design agreement, but on the other hand, it is more important to ensure that the final result of the operation is consistent with the original design goal. Regarding process technology management, the latter is the most easily ignored, but the latter is the most important!
Could it be that the quality of the calcium carbide is too poor and the sulfur and phosphorus content is too high? Although the efficiency of Zina has increased, it still cannot remove the sulfur and phosphorus.
I only answer your question from a chemical point of view! When you use silver nitrate test paper to test whether it contains phosphoric acid, what you want to see is whether the test paper shows* * , but iodide ions will also produce when they encounter silver nitrate * * precipitation! So it cannot explain the specific problem. You can add the yellowed test paper to the nitric acid solution and see if * * If it goes away, it means it does contain phosphoric acid, but if it doesn't go away, it means there are iodine ions! Of course, as for why there is iodine in calcium carbide! ! Or why does your iodine appear? I have no idea!
It has been seen that too much silver nitrate solution was prepared at one time and placed on site, resulting in contamination of the nitric acid solution. This problem can be solved by reducing the amount of time the silver nitrate solution remains on site. This post was last edited by limingshuguang on 2008-6-7 15:20 ]
If this situation occurs, is it possible to analyze at the same time? Measure three times in a row and take the average. I suspect there is something wrong with the measurement!
Haha, in fact, the simplest question is whether the liquid level of your purification tower is empty? If the liquid level is empty, the cleaning effect will definitely be yellow. Finally, adjust the liquid level of the purification tower to the process range, and the purification effect will be good.
If there is a short circuit in the cleaning tower packing and the gas-liquid contact is poor, no matter how high the sodium concentration is, the cleaning effect will not be achieved.
Then ask the analysis room to check the content of phosphorus ions to see if it contains phosphorus?