How to save energy in producing methanol from natural gas
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Energy conservation is a very important topic in the production of methanol from natural gas, and it needs to be constantly explored based on actual work. Our reformer is connected to the auxiliary boiler. Under the condition of constant load, the operation optimization of the reformer and auxiliary boiler is the most important for saving natural gas. I hope you will come to discuss it and communicate with us.
1. In terms of fuel gas, it is mainly the preheating of fuel gas and the control of air volume. Secondly, the purpose of preheating of purge gas is to prevent cold shock. The control of air volume is to effectively control combustion. The combustion value of purge gas is higher, but it is also a waste. 2. The conversion system is mainly the utilization of waste heat, especially the carbon dioxide in the flue gas, which is to reduce the number of starts and stops. 3. In the water system, I personally think that the control of dosage should be the first.
Isn’t the natural gas-to-methanol project banned now?
The natural gas policy is to refine and build new natural gas or coal-to-gas-to-methanol units. What is already a fait accompli still needs to be put into operation.
It is precisely because of the shortage of natural gas that we must save natural gas as much as possible
Looking at several key links in the production of methanol from natural gas, gas production accounts for more than 60% of the cost of the entire process. Therefore, the focus of energy conservation is on the production of syngas from natural gas. At present, the better process is the combination of various forms of steam reforming and autothermal conversion, which has resulted in many new gas production processes, such as U hde's CAR, ACAR, ICI's GHR, AGHR, Kellogg's KRES, Topsoe, Lurgi and other autothermal reforming processes. The energy consumption of these processes for methanol production has reached the peak of traditional methods, about ~29GJ/t methanol. The new gas generation process is an integrated oxygen and gas generation technology based on ceramic ion membranes, which eliminates the need for air separation and is expected to reduce gas generation costs by ~30%. Currently, both European and American ITM and OTM research teams are in the pilot development process.
Personally, I think that since the reformer is connected to the auxiliary boiler, the best way to save energy is to control the oxygen content of the auxiliary boiler. Since the combustion air used by the auxiliary boiler is the burned gas from the reformer, the temperature and oxygen content inside are within a certain range. Taking into account the low oxygen content of the reformer, try to keep the oxygen content of the flue gas at the outlet of the auxiliary boiler within a low range. Some factories control the oxygen content of auxiliary boilers at 2%.
The cost of producing methanol from natural gas is lower than that from coal, but natural gas is in short supply in my country. Just stop if you have to.
In actual work, I often explore energy-saving issues. There are several main points. Let’s see if they are right.: 1. All steam vent valves should be closed as much as possible to reduce unnecessary steam emissions. This requires careful operation of the steam system during work. 2. While ensuring various process indicators of distillation, reduce steam consumption and avoid wasting steam and losing methanol. 3. Optimize the combination of the top burner, flue burner, and superheated burner of the first-stage furnace, and adjust the furnace negative pressure to keep the oxygen content of the flue gas at 2% to 2.5%. This requires the main control to carefully fine-tune the on-site combustion conditions many times, and ultimately achieve the goal of using the least gas to produce the most steam within the scope of ensuring process safety. This job is tiring and requires a strong sense of responsibility and skilled skills. My own experience, I hope you can correct me.