Regarding the flow rate of the absorbent used to stabilize gasoline in the absorption stabilization system?

1. Stabilization is achieved by controlling the content of components with a molecular weight of C3 or higher in the dry gas supplied as a gasoline supplement; the allowable limit for such components varies from one plant to another. In our plant, this limit is set at no more than 4% (v/v). 2. The amount of supplement absorbent used is adjusted according to operational conditions, taking into account factors such as the volume of crude gasoline, temperature, the volume of rich gas, as well as the temperature and pressure in the absorption tower. Increasing the amount of supplementary absorbent can raise the absorption rate and reduce the content of components with a molecular weight of C3 or higher in the dry gas; however, this requires that the equipment have sufficient capacity, as it is necessary to increase the energy consumption of the reboilers in the desorption tower and the stabilizer tower to cover the additional energy demands associated with the use of more absorbent. The content of C3+ in the dry gas is determined through periodic sampling, usually once every 24 hours

Here, dry gas is sampled and analyzed on Mondays, Wednesdays, and Fridays

Our approach is to determine the amount of condensed oil sent to the separation tower based on a set value determined by the quality control of the dry gas. During operation, the amount of absorbent added is adjusted according to the liquid level in the condensed oil tank, while the amount of crude gasoline is adjusted as required by the distillation process. We conduct tests on the dry gas twice a week; if anything abnormal is detected during production, we can ask the laboratory to take samples at any time

1. Our target is no more than 3% (v/v). 2. The actual flow rate is generally higher than the calculated value. 3. We conduct analyses every 8 hours.

We also conduct analyses every 24 hours to keep the volume percentage at no more than 3, and the amount of supplementary absorbent is adjusted based on the mass of the dry gas. If you feel the operation is not very stable, you can contact Jiasai at any time.

I read the comments from the friends upstairs. Regarding the issue of determining the flow rate of the stabilizing gasoline supplementary absorbent, some suggest that the flow rate of this absorbent can be increased based on the calculated value. However, the question is: by how much should the actual flow rate of the stabilizing gasoline supplementary absorbent be higher than the calculated value? Is there a definite percentage value? ? Thank you!

Generally, there is no specific value; as long as the product meets the required standards, that’s sufficient. That’s how things work in practice – the calculations done by design firms are not necessarily accurate. . .

1 In the actual operation of the absorption stabilization system, what determines the flow rate of the absorbent used to supplement the stabilized gasoline? ? Is it controlled by the C3+ in the dry gas? If so, then how is the C3+ content in the dry gas controlled? ? Is it a quality basis or a volume basis? ? Answer: The flow rate of the stabilizing gasoline replenishment absorbent is adjusted and controlled based on the absorption efficiency, that is, by controlling the C3+ content in the dry gas. There should be specified requirements for various operational parameters, and these should be based on volume. 2 If the calculated flow rate for the stabilizing gasoline supplemental absorbent is 10 t/h, then when actually controlling this flow rate, should 10 t/h be used directly, or should a certain margin of safety be applied on top of that value, such as 12 t/h? Answer: This actually relates to ensuring that the separation and absorption towers function properly. There are multiple factors that affect the absorption efficiency; the liquid-to-gas ratio remains relatively constant, and it can be adjusted flexibly based on the analysis of the dry gas. 3 In actual plant operations, is the C3+ content in dry gas determined online or through periodic sampling? ? For periodic measurements, what is the appropriate period? ? Answer: There are both online measurements and periodic sampling measurements, and the measurement interval can be determined flexibly based on the actual conditions of the factory.

I saw someone above say that the control limit for C3 in dry gas is either not more than 3 or not more than 4; this seems a bit wasteful. We keep it below 2 and conduct sample analyses on a daily basis. It’s not necessary to keep the C2 content in liquefied gas too low, as long as it doesn’t affect operations, haha

1. Online testing is the best option, but it’s not feasible in actual production; only regular testing is possible； 2. There is a theoretical amount for the absorbent to be used, but in practice, the absorption efficiency and operational conditions are the most direct criteria for determination ； 3. As for the control index, it depends on the design capacity of the device; ours is below 2.

In the actual operation of the absorption stabilization system, what determines the flow rate of the absorbent added to stabilize gasoline? ? Is it controlled by the C3+ in the dry gas? If so, then how is the C3+ content in the dry gas controlled? ? Is it a quality basis or a volume basis? ? The flow rate of the supplementary absorbent can be determined based on two factors: the content of C3+ in the dry gas, which requires testing. We take samples for testing once a day during regular working hours. In practice, we adjust the settings in real time by considering the opening degree of the heat bypass at the top of the stabilizer and the amount of non-condensable gas discharged from the reflux stream at that location. Generally, when the absorption effect is good, the opening degree of the heat bypass remains stable, and the tower pressure is also under automatic control and stays stable. If the opening degree of the heat bypass decreases, it indicates an increase in the amount of non-condensable gas, and it becomes necessary to add more supplementary absorbent. Usually, there is very little non-condensable gas, and almost no such gas is discharged, as the absorption effect is good; if there is too much of it, then the absorption process will not work properly. The control parameter for the dry gas before separation is the level of C3 and above