Let’s discuss the 100,000-ton methanol technology at Huahua No.2 Plant and the two-stage conversion process used by Chengdu General
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Regarding coke oven gas, it is necessary to consider which technology has lower energy consumption, lower costs, higher production volumes, better product quality, fewer accidents, easier troubleshooting, simpler operation, and lower costs for routine maintenance. Additionally, it is important to discuss and compare whether centrifugal compressors, gas turbines, or combined reciprocating compressors are the better options for use in syngas compression. There are also cases where the design of these technologies is unreasonable, or where technical modifications or the addition of new components are required. (For example, in the design developed by the Second Chemical Engineering Institute, the notification of fan failures in the wet desulfurization process does not arrive in a timely manner, which can lead to accidents; could we install an alarm system in the compressor control room to detect such fan failures?)
Someone messaged me asking about the second-stage conversion process; I’ll explain it. The gas coming from the compressor passes through filters A/B → heat exchangers → the first preheater for the feed gas → the second preheater for the feed gas → heater A → pre-hydrogenation of iron and molybdenum → hydrogenation of iron and molybdenum → desulfurization of iron and manganese → heat exchangers → hydrogenation of nickel and molybdenum → desulfurization using zinc oxide → heater B → supplemental steam → gas-to-gas heat exchangers A/B → shift converter → conversion reactor → gas-to-gas heat exchangers A/B → the second preheater for the feed gas → waste heat boiler → the first preheater for the feed gas → boiler feedwater preheater → first separator → the conversion gas in the atmospheric pressure tower in a boiler → second separator → the conversion gas in the pressurized tower in a boiler → third separator → desalinated water preheater → water cooler → fourth separator. As for the oxygen stream: oxygen enters heater B → then enters the conversion reactor
The methanol production from coke oven gas designed by the Second Chemical Engineering Institute makes rational use of thermal energy, thus saving energy.
The methanol production from coke oven gas designed by the Second Chemical Engineering Institute makes rational use of thermal energy, generates a large amount of by-product steam, and employs steam turbines to drive centrifugal compressors in order to save electricity. If the steam inlet pressure of the turbine is designed to be at the same pressure level as that of the synthesis drum, and if the gas released from the synthesis process is recovered and used as fuel for the heating furnace, as well as if saturated steam is converted into superheated steam, it will result in greater energy savings. Transmit the vehicle-jumping alarm signal to the DCS system to generate a display, trigger an alarm, and allow the personnel in the control room to inform those with good coke pressure control.
Without a power plant, can the process at the Second Chemical Engineering Institute ensure its own operation? Is the steam it generates sufficient?
Two-stage pure oxygen conversion is more energy-efficient; for coke oven gas, centrifugal compressors are likely the better choice. As for reliability, it depends on the production capacity of the facility and the characteristics of the entire system.
It’s not just about energy savings; there’s also the issue of conversion efficiency. The specific process to be used is determined based on one’s own actual circumstances. But is it possible to find common advantages in both approaches, areas where the two design institutes haven’t yet referred to each other’s work?