Comparison of methanol technology between ICI and Luigi processes: please give me your advice and supplements
Thread Content
Project Luigi method ICI method 1. Synthesis pressure MPa 5.0-8.0 5.0-10.0 2. Synthesis reaction temperature ℃ 225-250 230-270 3. Catalyst composition Cu-Zn-Al-V Cu-Zn-Al 4. Space-time yield tons/m3* hour 0.78 0.78 5. CO content in the gas entering the tower ~12 ~9 6. Methanol content in the gas leaving the tower 5-6 5-6 7. Circulating gas: synthesis gas 5:1 4:1 8. Utilize the heat of synthesis reaction, use the by-product steam, do not use the heat of reaction, do not use the heat of reaction, use the by-product steam 9. The synthesis tower forms a tubular cold-shock type, tube-cooling type, tube-cooling, by-product steam 10. The size of the equipment is compact, the equipment is larger, compact and compact 11. The synthesis start-up equipment does not have a heating furnace, but does have an start-up heating furnace. 12. Methanol distillation adopts a three-tower process and a two-tower process.
It would be nice if there were two ways to invest. However, many methanol plants now use Lurgi’s synthesis technology.
Can you please add the ratio of by-product medium-pressure steam and refined alcohol production?
First, the ICI multi-stage cold-shock methanol reactor and the Lurgi tube are cold synthesis towers. Secondly, the advantages of Lucci: 1) The bed temperature is relatively stable. 2) By controlling the pressure of the synthesis drum, the reaction temperature of the synthesis tower can be accurately and sensitively controlled. 3) The exported methanol content is high and has been successfully used in various parts of the world. 4) The temperature is constant, which can effectively control side reactions and avoid the formation of paraffin and carbonyl compounds. 5) Easy to operate and control, and there is no danger of over-temperature of the catalyst. The catalyst has a long service life. 6) High-level energy and heat can be recovered, and 1.0-1.4 tons of medium-pressure steam of 4.0MPa can be produced for every ton of methanol produced. 7) Compact structure, easy start-up and small pressure drop.
Is the 4.0MP steam mentioned above a bit too high? Although many catalyst manufacturers say that their active temperature can reach 340 degrees, for the currently popular low-pressure synthesis, it is rare to increase the pressure of the medium-pressure drum to that high, unless the catalyst reaches a late stage or the airspeed is too high, and the heat is difficult to maintain. Of course, it also has a lot to do with your own process conditions. For example, due to the different loads of the synthesis tower and the actual requirements of multiple cycles, the parameters in the operation process will be different between the combined alcohol and the monool. For example, we are now in the joint alcohol industry, and the catalyst has been used for almost two years. The medium-pressure drum pressure of the synthesis tower is still 2.6 (A) MP, the synthesis pressure is about 7.0 MP, and the inlet temperature above 200 can meet the single-pass 90% (CO+CO2) conversion requirement. At the same time, according to relevant information, too high a synthesis temperature will cause many side reactions. Therefore, if the process allows, it is better to control the pressure of the steam drum lower, which can reduce a lot of troubles in the distillation process.
I also think Rucci's technique is better, the most obvious are two things 1. Synthetic tower temperature control 2. High one-way conversion rate
Sichuan Vinylon Factory introduced ICI methanol technology in the 1970s. Later, due to high energy and material consumption, it underwent technical transformation from 1996 to 1998 and switched to Xiaoguizi's MRF-Z reactor.