Adjustments regarding the density flash point of diesel
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This post was last edited by The Happiest Person on 2023-3-18 at 17:36. Recently, diesel meeting National VI standards is produced, with a density not exceeding 0.845 g/ml and a flash point of not less than 60℃； Currently, the produced diesel has a density on the higher side, a flash point on the lower side; its initial boiling point is around 175°C, the dry point at 95% purity is around 340°C, and it does not reach 370°C as a dry point℃ ； The dry point of naphtha is around 165°C, while the temperature at the outlet of the distillation furnace is only 290°C. If the temperature at the outlet of the distillation furnace is increased, the density of diesel will exceed the specified limits; reducing the temperature at the top of the tower will result in a diesel flash point that does not meet the requirements. The yield of diesel is then only 60%, with the pressure in the distillation tower remaining constant at 0.07 MPa. How to make adjustments to better control diesel density and flash point, and improve diesel yield.
To address this situation, the following adjustments can be considered: 1. Adjust the feed ratio. The feed amount of naphtha can be increased appropriately, and the feed amount of diesel can be reduced, in order to lower the density of diesel. 2. Adjust the operating conditions of the fractionation tower. It is possible to try increasing the outlet temperature of the fractionation tower, while appropriately reducing the top temperature of the tower, in order to control the density and flash point of diesel. The specific operating conditions need to be adjusted according to the actual situation, and can be optimized through methods such as simulation. 3. Optimize the catalyst. Consider changing or adjusting the type and amount of catalyst to improve diesel yield and control density and flash point. 4. Install a slitting machine. Installing a splitter in the distillation tower increases the number of temperature gradients within it, which enables better control over the density and flash point of diesel, as well as an improvement in the yield of diesel. It should be noted that safety operating procedures must be strictly followed during the adjustment process to ensure production safety. .
The density and flash point of diesel are usually adjusted during the manufacturing process. Some common methods include adding diluents, changing the material composition, and altering the production process. If it is necessary to increase the density of diesel, heavier compounds such as aromatic hydrocarbons or alumina can be added. Conversely, if it is necessary to reduce the density, lightweight compounds such as methane or ethane can be added. To adjust the flash point, it is possible to increase it by adding components with a higher flash point, such as mineral oil or other oils with a higher viscosity. In addition, flash point elevators can also be used; these are chemical additives that effectively increase the flash point. Overall, adjusting the density and flash point of diesel is a complex task that requires careful analysis and optimization based on specific circumstances. .
From the analysis, the dry point of naphtha and the initial boiling point of diesel have separated, and the dry point of naphtha has essentially reached its lower limit; it is no longer possible to increase the yield of diesel. To increase the diesel yield, adjustments need to be made starting with the material before it enters the tower; if the unit includes a reaction step, the cracking temperature can be reduced appropriately to lower the gasoline yield. As diesel density increases, it is blended with light diesel or kerosene components.