Methanol production per unit of catalyst
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Recent reports indicate that the low-pressure methanol production plant at Shandong Yankuang Lunan Fertilizer Factory produces the most methanol using coal-derived methyl alcohol-based catalysts; under similar conditions, the service life and production efficiency of these catalysts were evaluated across three batches. As the sulfur absorption capacity of methanol catalysts decreases, both their service life and production efficiency increase significantly. This has led to the establishment of a new record at home and abroad: catalysts used in the low-pressure methanol synthesis process from coal have a service life of over 4 years and 10 months, with a production efficiency of 31,800 t/m3. I wonder what the performance was in the final stages – was it continued despite the difficulties just to break the record? If the indicator of methanol consumption per ton of synthesis gas at the end of the process is high, there is little by-product steam, the compressor current is high, and the distillation reflux ratio is large, it’s not easy to achieve such results either, right? Could someone who is aware of the situation explain what’s going on in the final stages? I did the math: to break the record, it’s necessary to operate at 100% capacity for 1,600 days, which is just as difficult. Next, I would like to ask those in the industry who have replaced their catalysts: what is the highest record currently achieved by any factory? For the production of methanol from natural gas, as far as I know, Mitsubishi’s catalysts are used in overseas projects, where 40,000 tons of methanol can be produced per cubic meter of catalyst.
The catalysts produced by Mitsubishi Gas work very well when used in gas burners. We act as an agent for their catalysts; they have provided us with data showing that their efficiency can reach 40,000–60,000 tons per cubic meter
This post was last edited by Proud Eagle on 2012-3-22 at 20:26. Currently, in China, only Lunan has the highest yield of 31,800 tons/m3. Foreign catalysts have not yet reached 40,000 tons/m3 in China. The syngas produced from coal contains a high level of CO and many impurities ； H2 is abundant when it’s in an excited state, with few impurities. Generally speaking, catalysts based on coal are less effective than those based on gas. Sorry, I made a mistake. It is 31,800.
This post was last edited by Shouhou on 2012-3-21 at 11:44. Who told you that the catalyst cost is 36,800 tons per cubic meter? The news I mentioned is quite recent; how is it possible that such a record has already been broken in such a short time?
I don’t know much, but reading your discussions has really benefited me! Powerful
The record-breaking production unit in southern Shandong had an exit temperature of 240 degrees and an inlet temperature of 211 degrees; based on these temperatures, there is still room for further use. I think a factory will definitely take into account energy consumption and process factors when deciding whether to replace the catalyst, and it won’t push itself to break records just for that sake. There are several main reasons why Lunan performs well: 1. Strict control of gas parameters; initially, the hot spot in the synthesis tower was at 228 degrees ； b. The pressure at the inlet of the tower is 4.0–4.5 Mpa. c. The CO content at the inlet of the tower is 5–8%. d. The CO2 content at the inlet of the tower is 3–5%. 2. Strict control over the temperature rise in the synthesis tower. 3. Control of sulfur content in the fresh gas; the total sulfur content in the fresh gas should be kept below 0.05 ppm. The analysis at the inlet of the synthesis tower shows a value of less than 0.03 ppm (using the domestically produced trace sulfur analyzer HC-2, with a minimum detection limit of 0.03 ppm). 4. Utilize the best catalysts available in China: the C307 methanol synthesis catalyst produced by Nanjing Institute of Chemical Technology. However, only by mastering and applying scientific methods can good catalysts truly leverage their advantages.
Could I take a look at the import and export data for the final stage? The controls you mentioned are requirements that almost every factory has to follow; however, when production is unstable, there will definitely be differences in the level of control among different factories. Still, it’s really admirable that they manage to achieve such a high output per cubic meter of catalyst – I truly respect both the management team and the front-line workers. It’s easy to persevere for a month, but difficult to do so for 5 years.
The moderator said that the data used are from the end stage: for the gases entering the synthesis tower, the composition is 11.46 for CO, 4.17 for CO2, and 1.42 for CH4; while for the gases exiting the synthesis tower, the composition is 8.54 for CO, 3.7 for CO2, and 1.78 for CH4. These values are only approximate, as no data is available for the other components. The volume of gas entering the tower is around 290,000, with a pressure of 4.9 Mpa
The CO2 conversion rate is very high; the CO level remains basically normal at the end. We have used three units of NC-307, and in each case the CO conversion rate was above 40% during replacement, but the CO2 level never exceeded 30% at the beginning. It’s possible you remembered something incorrectly. Anyway, thanks!
It must be a mistake; CO2 indeed cannot have such a high conversion rate. :lol
Is it okay to initially control the hot spot temperature in the synthesis tower at 228 degrees? Is the pressure control also a bit too low? What is the recycle ratio? Thank you