Methanol synthesis
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I have 10 questions for everyone: 1. Why is a line filter installed on the pipeline between the methanol separator and the methanol flash tank? What are its functions and structure? 2. The waste water from the synthesis tower’s drum is sent to the waste water expansion tank – what is the purpose of this? What about the gas that is finally flashed off? Finally, where does the wastewater get discharged to? Are there any relevant discharge standards? 3. What is the typical flash pressure for a methanol flash tank? 4. After methanol is separated in the methanol separator, the gas resulting from this separation mixes with the gas that comes from the flash tank. In some plants, this mixed gas is sent to an alcohol washing tower for further treatment before being released; in other plants, it is discharged directly. What are your thoughts on these two different processing methods? 5. Why are shut-off valves and control valves installed on both the gas and liquid pipelines of the methanol separator? What are their functions? 6. The liquid level in the synthesizer drum is generally interlocked with that equipment. What is its function? 7. There is a sampling port on the inlet pipeline of the preheater for the gas entering the tower; what is mainly analyzed here? 8. There is a spare interface on each of the pipelines running from the inlet preheater to the methanol synthesis air cooler, and on the pipeline running from the methanol synthesis air cooler to the methanol water cooler. What is the purpose of these two interfaces? 9. There is a sampling port on the drain line of the methanol synthesis drum; what is it mainly used for analyzing? 10. There is a sampling port on the discharge pipeline of the methanol flash drum. What is mainly analyzed there? I want to work in the methanol industry; I’m a beginner at the moment. I’ve asked a few questions here, hoping that everyone can help me out. Thank you very much to all the members of the methanol forum.
Learn more from the original poster*; when facing problems, try to find out more about them@@
1. It’s something similar to the filter at the pump inlet; its function is to protect the control valve and the flash tank. 2. This refers to the continuous drainage from the gas holder – ions get concentrated, and when the concentration is high, scaling occurs. Phosphates are added; it’s not wastewater, only phosphorus levels may exceed the limits, depending on local regulations regarding phosphorus emissions. 3. A level of over 3 kilograms ensures that the liquid level can enter the distillation unit steadily. The lower the pressure, the more thorough the gas flashing, but more methanol is wasted in this process. 4. If possible, all water should be washed out before discharge, as this helps save energy and reduce consumption. 5. There should be valves in place to ensure normal operation; what if maintenance needs to be carried out without shutting down the entire system? 6. The liquid level is usually linked to the compressor – when the level drops, gas supply is automatically cut off and the compressor stops working. 7. Inlet analysis is the most important aspect, as it is at this point that the composition of the material is controlled, thereby influencing the synthesis reaction. The composition of the fresh gas is actually controlled indirectly. Additionally, methanol and carbonyl compounds can also be analyzed; during reduction processes, hydrogen and oxygen can be used as well. 8. It seems to be used for displacement or dewaxing purposes. 9. The quality of boiler water needs to be analyzed; the specific indicators vary from one factory to another. The goal is to prevent damage to the heat exchanger structure. Common indicators include phosphates, chloride ions, SiO2, pH, etc. 10. Impurities in crude methanol need to be analyzed as well.
In the future, it’s better to ask your experienced colleagues first; it will be more beneficial for you. After all, explanations might not always be completely clear
Thank you to the friend upstairs for providing such a detailed answer; I’ve learned something from it. I have another question: there is a sampling point on the pipeline that leads from the methanol separator gas to the compressor. What is this sample mainly used for analyzing? Thank you, brothers and sisters, for your advice.
This sampling point should be for analyzing the composition of the recycle gas.
The explanation on the 4th floor is quite good. I think the number 8 refers to the chemical cleaning port; there is a dedicated nitrogen pipeline for replacement, and wax removal takes place mainly in the separator.
An explanation on the 4th floor would be better; however, the fact that such a question is asked suggests that the person has never been involved in the chemical industry before and lacks any professional theoretical knowledge. One should pay more attention to the procedures used in one’s own workplace or seek advice from experienced colleagues. Question 2: As explained in chemical engineering thermodynamics, the vapor that emerges from flashing is generally low-pressure steam at 0.4 MP, which can be recovered as waste heat for use in heating, warming, and other applications. It also varies depending on the process. Question 6: The interlock connected to the compressor is actually the shutdown interlock of the synthesis system; if the steam drum also reaches a low-low level, the heat generated by the reactor cannot be removed, which can damage the tubes of the water-cooled reactor. Question 7: The sampling port is provided to constantly monitor the gas composition of the gas entering the tower, so that various process parameters can be adjusted accordingly. Question 8: A spare port is provided, which can be used for two purposes: as a steam port for wax removal by steam, or as an outlet for wax. Also, if the cooling capacity designed during production is not sufficient to meet the actual production needs, a heat exchanger can be added at the spare port. It fully meets the actual production needs.
I work in filtration technology; I study *study*.
1. Since the synthesis reaction is accompanied by many side reactions, paraffin crystallizes; the filter primarily filters out paraffin