【Gas Phase】Gas fractionation unit
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This post was last edited by Xiao Gong 1985 on 2016-1-29 09:19. Dear experts, what should be the reflux ratio at the top of the gas fractionation unit? How should operations be adjusted when both propane and propylene products fail to meet the quality standards?
If the equipment permits, it is possible to reduce the feed rate first; once the quality meets the requirements, the feed rate can be increased gradually. If this is not allowed, it is necessary to ensure that the quality of the product that must meet the standards is satisfactory first, and then make adjustments slowly. For reference, the propylene reflux ratio of our unit is 12–15.
Reduce the flow rate, increase the low-temperature and reflux ratios, control the pressure at the top of the tower as well as the temperature after cooling; by proceeding gradually in this manner, recovery should be possible.
Adjust the feed rate; if that doesn’t work, stop feeding and switch to single-column circulation until the quality meets the standards. If the amount stored in the tower is too large, an appropriate amount of substandard products should be transferred to the raw material tank to maintain a normal storage level.
The answer is upstairs. Additionally, it is necessary to consider whether there is a problem with the tray, which has led to a decline in separation efficiency. Reducing the volume should be the first choice.
When propylene fails to meet the specifications, it is almost certainly due to too high a base temperature, which results in the presence of propane; whereas when propane fails to meet the specifications, it is almost certainly because of the presence of C4 compounds. Stop feeding material, discharge the propane, and reduce the temperature. Is that so?
The main reason is an excessive processing volume and too large a amount of material in the tower, which leads to a poorer separation effect. The dosage can be appropriately reduced
Alternatively, increasing the amount of propane supplied and adjusting the reflux rate accordingly can only ensure the quality of propylene; this will result in a high propylene content in the propane, thereby reducing the yield of propylene.