Control the 95% point of diesel

To control the 95% point of diesel, the following information is necessary: 1. The separation of diesel within the tower; 2. The function of the top reflux; 3. The functions and adjustment methods of the first, second, and third side streams; 4. The actual steps for controlling the 95% point of diesel. Answers to the above questions are as follows: 1. Separation of diesel within the tower: Diesel is a mixture of alkanes with various carbon numbers, and it is separated within the distillation tower based on their boiling points. Generally, the 95% point for diesel is n-heptane, with a boiling point of about 208°C. 2. The function of top reflux circulation: Top reflux circulation refers to the installation of a reflux device at the top of the tower, which allows a portion of the liquid at the top of the tower to flow back to the bottom of the tower. This increases the residence time of the material within the tower, thereby enhancing the separation efficiency. Top reflux top circulation can also be used as one of the methods to control the 95% point of diesel. 3. Functions and adjustment methods of the first, second, and third side lines. The first, second, and third side lines refer to discharge pipes installed within the tower perpendicular to the tower’s axis, which can be used to collect fractions within different carbon number ranges. In controlling the 95% point of diesel, the purity of the diesel fraction can be influenced by adjusting the flow rates of the first, second, and third side streams. 4. Actual operational steps for controlling the 95% point of diesel During the process of controlling the 95% point of diesel, the following steps are required: (1) Collect and analyze the laboratory test data of the diesel feed to determine the actual boiling range of the 95% point of the diesel. (2) By adjusting parameters such as the temperature of the bottom heater and the reflux ratio, an appropriate temperature gradient is created within the tower to facilitate the separation of diesel fractions. (3) Adjust the reflux ratio, as well as the position and flow rate of the top reflux, appropriately according to the actual conditions. (4) By adjusting the flow rates of the first, second, and third side lines, fractions within different carbon number ranges are collected and separated, thereby achieving control over the 95% point of diesel. In summary, controlling the 95% point of diesel requires a comprehensive consideration of factors such as the separation of materials within the tower, the operating parameters of the bottom heater, the reflux flow rate and location, as well as the adjustments made to the side streams. .

For distillation columns with a relatively small processing capacity, it is generally sufficient to increase the extraction temperature slightly and reduce the secondary and tertiary reflux rates. For distillation columns with a larger processing capacity, it is necessary to consider all aspects related to the extraction temperatures and reflux adjustments; otherwise, it will affect the quality of the products obtained from the upper and lower side streams.