Methanol Section: One Question per Day. What is the significance of controlling the temperature of the gas after it has been cooled by synthetic water? 2016.03.31
Thread Content
Methanol Section: One Question per Day. What is the significance of controlling the temperature of the gas after it has been cooled by synthetic water? 2016.03.31 What is the significance of controlling the temperature of the gas after it has been cooled by water? Answer: The high-temperature gas at the outlet of the synthesis tower is cooled by a water cooler, after which the methanol and water vapor in the mixture are condensed into liquids. Following this, crude methanol (water and methanol) is separated out using a separator. The amount of condensate separated depends on the temperature and pressure after cooling. Generally, the temperature is controlled below 40°C for methanol synthesis via the low-pressure method; after cooling and separation, the methanol content in the gas is 0.6%, while it can be less than 0.1% using the high-pressure method. If the temperature of the mixture is controlled too high, it will affect the condensation of crude methanol. As a result, an increase in the content of crude methanol gas in the recycle gas raises the power consumption of the recycle gas compressor, and it also hinders the reaction from proceeding in a direction that favors methanol production. However, it is also not necessary to keep this temperature too low. When the temperature of the mixture drops below 20°C, the improvement in the condensation of crude methanol is not significant; therefore, striving for an excessively low water cooling temperature increases the design requirements for the water cooler as well as the consumption of cooling water, which is not economical.
Answer: If the temperature of the gas after cooling is controlled too high, it will affect the condensation of methanol and water vapor in the gas. As a result, the amount of methanol that remains uncondensed in the syngas increases. This methanol not only raises the power consumption of the compressor but also inhibits the methanol synthesis reaction within the synthesis tower. However, it is also not necessary to keep the temperature of the gas after cooling it with water at too low a level. When the gas temperature drops below a certain threshold, the improvement in methanol condensation is not significant; therefore, striving for an excessively low cooling temperature is not economical
If the temperature of the gas after cooling in the synthesis process is controlled too high, it will affect the condensation of methanol and water vapor in the gas. As a result, the amount of methanol that remains uncondensed in the syngas increases; this methanol not only raises the power consumption of the compressor but also inhibits the methanol synthesis reaction within the synthesis tower. However, it is also not necessary to keep the temperature of the gas after cooling it with water at too low a level. When the gas temperature drops below a certain threshold, the improvement in methanol condensation is not significant; therefore, striving for an excessively low cooling temperature is not economical.
Answer: The high-temperature gas at the outlet of the synthesis tower is cooled by a water cooler, after which methanol and water vapor in the mixture are condensed into liquids. Following this, crude methanol (water and methanol) is separated out using a separator. The amount of condensate separated depends on the temperature and pressure after cooling. Generally, the temperature is controlled below 40°C for methanol synthesis via the low-pressure method; after cooling and separation, the methanol content in the gas is 0.6%, while it can be less than 0.1% using the high-pressure method. If the temperature of the mixture is controlled too high, it will affect the condensation of crude methanol. As a result, an increase in the content of crude methanol gas in the recycle gas raises the power consumption of the recycle gas compressor, and it also hinders the reaction from proceeding in a direction that favors methanol production. However, it is also not necessary to keep this temperature too low. When the temperature of the mixture drops below 20°C, the improvement in the condensation of crude methanol is not significant; therefore, striving for an excessively low water cooling temperature increases the design requirements for the water cooler as well as the consumption of cooling water, which is not economical.
The warm gas exiting the Chenghe tower passes through a high-water-cooled subcooler, where it mixes; the methanol and water vapor in it are condensed into liquid form. After passing through a separator, crude methanol and water (methanol and water) are separated out. The amount of condensation and separation depends on the sum of temperature and pressure in multi-view cooling. The typical control temperature is below 0°C; under low-pressure conditions, the alcohol content in the gas phase after cooling is 0.%, while high pressure can reduce this value to 0.1%. If the mixing ratio and temperature control are not properly managed, it will significantly affect the cooling effect of crude alcohol. The increase in the alcohol content within that medium-thick armored gas in the gas loop leads to higher compression power consumption for the gas compressor; moreover, in the synthesis reaction this facilitates a reaction progression that favors the formation of methanol. However, there is no need to control the temperature too low either. When the temperature of the mixture falls below 20°C, the cooling effect on n-propyl alcohol increases significantly. Attempting to achieve a very low outlet water temperature leads to higher design requirements for the cooler as well as greater water consumption, which is not economical.
The optimal points of technology and economics, learned on Floor 2!
The separation effect is poor, which affects the reaction equilibrium in the synthesis tower and can also cause the compressor to operate with liquid present
The high-temperature gas at the outlet of the synthesis tower is cooled by a water cooler; as a result, methanol and water vapor in the mixture are condensed into liquids. After passing through a separator, crude methanol (water and methanol) is separated out. The amount of condensate separated depends on the temperature and pressure after cooling. The temperature is generally kept below 40 degrees to reduce the energy consumption for methanol vapor.
The gas exiting the tower after being cooled by the water cooler has most of its methanol and water condensed into liquids; it then enters a separator where crude methanol is separated out. The effective gas resulting from this process contains approximately 0.611% methanol vapor. If the temperature of the gas entering the separator increases, the concentration of methanol vapor rises, and this will affect the quality of the methanol produced when the gas is sent to the synthesis tower under pressure. The increase in by-products causes problems for distillation. At the same time, compressors are prone to causing liquid slugging. It’s unnecessary when the temperature is too low; it wastes a lot of cooling water.