Basis for controlling the top temperature of the amine liquid regeneration tower
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How are factors such as the composition of the amine-rich liquid, the amount of steam supplied to the reboiler, and the load on the tower affecting the top temperature during amine solution regeneration? How can the optimal temperature be determined in order to save energy and reduce consumption?
The operating conditions of the regeneration tower are greatly influenced by the load and the hydrogen sulfide and carbon dioxide contents in the amine-rich liquid. In towers with high loads, the pressure drop is large, and the temperature difference between the top and bottom of the tower is significant; for example, in one of our regeneration units, the bottom temperature has consistently been 124 degrees, while the top temperature is even less than 100 degrees. The acid water reflux ratio is also low. For towers with low load, the top temperature I’ve seen is generally around the same, in the range of 107–112. As for the bottom temperature, there are periods when it is kept at 115, other periods when it is kept at 118, and yet other periods when it is kept at 121. The lower the levels of hydrogen sulfide and carbon dioxide in the amine solution, the lower the levels of these same gases as non-condensable components in the acidic gas at the top of the tower. At a constant control pressure, a higher water vapor partial pressure is required, which in turn results in a higher temperature at the top of the tower. In short, it is necessary to determine the appropriate operating conditions based on the quality requirements of the lean amine solution, taking into account factors such as the load, the hydrogen sulfide content in the rich solution, the steam consumption per unit volume, and the acid water reflux ratio.
I think the fundamental basis is to control the leanness of the lean liquid.
Based on the quality of the lean liquid, we maintain the top temperature of the tower at around 113°C, with a steam consumption per ton of rich liquid of about 90 kg/t, and a reflux ratio at the tower top of around 6%.
Our regeneration system is a supporting unit for sulfur treatment plants; it features full reflux control at the tower top. The concentration of the lean liquid is generally not monitored, as the key factor is whether the flue gas emissions meet the specified standards. If the quality of the lean liquid is good, then the emissions will naturally be satisfactory. Thank you for your guidance: lol
What are the main factors affecting the specific steam consumption?
With all other conditions remaining unchanged, it depends directly on whether your emission targets are met!