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Vacuum distillation Back

Action Separation
Method Thermal
Purpose Separate without cracking
Feedstock Residues from atmospheric tower
Product(s)

Gas oil
Lube stock
Residue

Product(s) goes to

Catalytic cracking
Residual treating & blending
Solvent deasphalting
Coking
Visbreaking
Solvent extraction
Residue hydrotreating

The vacuum distillation unit operates below atmospheric pressure. This is required to prevent thermal cracking when distilling the residue or topped crude from the atmospheric tower.

A typical first-phase vacuum distillation may produce gas oils, base oils and heavy residue for propane deasphalting. A second-phase distillation, operating at a lower vacuum, distills excess residue from the atmospheric tower which is not used for lube stock processing, and excess residue from the first vacuum tower not used for deasphalting.

Vacuum distillation units are also used to separate fluid catalytic cracker feedstock from excess residue. Vacuum distillation bottoms may also be sent to a coker and used as wax, grease, lubricant or asphalt stock, or desulfurized and blended to low-sulfur fuel oils.

DMA Generation M

The DMA Generation M density meters measure the density and concentration of liquids. They provide preset measuring methods and integrated conversion tables for many applications. The FillingCheckTM function automatically detects filling errors and gas bubbles in the sample to avoid measuring errors.

Accuracy, density:
0.0001 g/cm³ (DMA 4100 M)
0.00005 g/cm³ (DMA 4500 M)
0.000005 g/cm³ (DMA 5000 M)

Repeatability s.d., density:
0.00005 g/cm³ (DMA 4100 M)
0.00001 g/cm³ (DMA 4500 M)
0.000001 g/cm³ (DMA 5000 M)

Benefits of DMA Generation M at Vacuum distillation

DMA 4100 M and DMA 4500 M can directly measure API gravity (calculated from true density), a necessary parameter for quality control of process samples coming from atmospheric distillation. The conversion from density to API gravity is implemented according to ASTM D1250 (product group B: refined products).  A sample changer is used for high sample throughput (Xsample 452) and allows for highly repeatable results (Xsample 352/452). For heavy products, the conversion from density to API gravity is implemented according to ASTM D1250 (product group D: lubricants).

DMA 500

DMA 500 is a convenient, compact laboratory density meter providing renowned DMA measurement quality at the push of a button. Operations with DMA 500 are safe against voltage fluctuations and power outages due to the instrument’s integrated rechargeable battery, which also enables flexible off-the-line operation. The U-ViewTM live camera image of the measuring cell allows for visual inspection of the filling process and is supported by an automatic FillingCheckTM resulting in a high level user-support.

Accuracy, density:
0.001 g/cm3

Repeatability s.d., density:
0.0002 g/cm3

Min. sample volume:
approx. 1 mL

Maximum off-the-line operation:
2 h (optionally 6 h)

DMA 4200 M

The DMA 4200 M density meter determines density and specific gravity at sample pressures up to 500 bar and temperatures up to 200 °C. DMA 4200 M  is the expert solution for highly viscous samples with high melting points like bitumen, asphalt or tar, for volatile samples like fuel and gases like LPG (liquefied petroleum gas).

Density range:
0 to 3 g/cm3

Temperature range:
-10 °C to 200 °C

Pressure range:
0 bar to 500 bar

Accuracy, density:
0.0001 g/cm3