About distillation

The distillation range of petroleum products is related to the content of applicable substances. If the distillation range meets the requirements of product technical standards, it indicates that the content of applicable substances meets the requirements for use, and the distillation range is one of the quality indicators.

Initial boiling point: When the first drop of condensate dripping from the end of the condenser tube, the thermometer reading is observed instantaneously.
Dry point: The last drop of liquid that flows out of the condenser at the same time as the liquid in the distillation flask evaporates instantaneously. At this moment, the thermometer reading is observed instantaneously. However, it does not include any droplets or liquid films on the walls of the distillation flask or on the temperature measuring device.
It must be said that the dry point is not the final boiling point, and the final boiling point is the highest temperature, which occurs after all the liquid at the bottom of the distillation flask has evaporated.
It must also be emphasized that all solvent oil products are based on dry spots.
Residue: When dry, the portion that is not distilled is called a residue.
Distillation range: The temperature range from the initial boiling point to the dry point or the final boiling point, called the distillation range.
The boiling point is not the initial boiling point, and the boiling point is the temperature at the time of boiling.
The boiling range is also not the distillation range, and the boiling range is the temperature limit of boiling. Only after boiling, steam is formed to distill the separated material, so the distillation range is higher than the boiling range, and the upper limit of the boiling range and the lower limit of the distillation range are coincident. Only the concept of relatively pure materials can be replaced.
Decomposition point: The thermometer reading corresponding to the initial signs of thermal decomposition in the liquid in the distillation flask.
Percentage of recovery: Percentage of condensate volume observed in the receiving cylinder while observing the thermometer reading.
Percent Residue: The volume percent of residual oil remaining in the flask after the distillation flask has cooled.
Maximum recovery percentage: Due to the early termination of distillation at the decomposition point, the corresponding recovery percentage of the liquid volume in the received amount is recorded.
Total recovery percentage: The sum of the maximum recovery percentage and the residual percentage.
Percent evaporation: The sum of percent recovery and percent loss.
Light component loss: Refers to the volatilization loss of the sample transferred from the receiving cylinder to the distillation flask, the evaporation loss of the sample during the distillation, and the unvaporized sample vapor loss in the distillation flask at the end of the distillation.