Thermal Cracking (Visbreaking)

Thermal cracking pilot plant services (units P2 and P3)

Process Description
Thermal cracking (or visbreaking) reduces the viscosity of a resid and converts it to valuable products that otherwise cannot be recovered from the residue by conventional distillation. Visbreaking lowers the pour points of waxy residues and enables the refiner to blend heavier materials with lighter fuel oils. Coil temperatures can be raised to increase the yields of lighter products just until coke formation starts to lead to a pressure increase across the visbreaker coil.

Unit Description
Unit P2 is a continuous pilot plant that can be configured to divert the flow to a visbreaker coil instead of the coke drums. It includes a downstream distillation train (flash tower, stabilizer, atmospheric tower and vacuum tower) that can be used to generate a bottoms stream for simulating a recycle operation. The residence time is controlled via coil volume above incipient cracking temperature with eight coils in separate lead pot heaters. The eight coils range in diameter from 1/4 inch to 3/8 inch with a total combined volume of 2.99 liters.

Unit P3 is a continuous pilot plant that can be configured to divert the flow to a visbreaker coil instead of the coke drum. This unit does not have an integrated downstream distillation train. The residence time is controlled via coil volume above incipient cracking temperature with one coil in a fluidized sand bath. The coil has a diameter of 1/4 inch with a total volume of 0.18 liters.

The core design specifications for units P2 and P3 are as follows:

Unit IDFeed Rate -MinimumFeed Rate -MaximumVisbreaker Coil
Temperature -Maximum
Visbreaker Coil
Pressure -Maximum
Unit P21.0 L/h (0.26 gal/h)5.0 L/h (1.32 gal/h)537.8 °C (1,000 °F)103.4 bar (1,500 psig)
Unit P30.4 L/h (0.10 gal/h)1.0 L/h (0.26 gal/h)537.8 °C (1,000 °F)13.9 bar (200 psig)

Additional attributes to note:

  • Unit P2:
    • Can include slip streams of nitrogen or steam upstream of the coil
    • Online refinery gas analyzer for speciating C1 through C5
  • Unit P3:
    • Can include slip streams of nitrogen or steam upstream of the coil
    • Offline refinery gas analyzer for speciating C1 through C5

Analytical Support

Analytical types and frequency are performed on an as needed basis to ensure that customers are getting only the data they need when they need it. Onsite and external analytical support options are available for characterization and unit control purposes.

In-house analytical support for unit control and external analytical support via the Intertek network of laboratories is as follows:

In-house:
  • D287 API Gravity
  • D2887 GC Distillation
  • D3279 Heptane Insolubles
  • D445 Kinematic Viscosity
  • D4740 Spot Test
  • D5950 Pour Point
  • D6352 GC Distillation
  • D70 Density
  • D893A Pentane Insolubles
  • D893B Toluene Insolubles
Intertek network:
  • D4294 Sulfur
  • D5762 Nitrogen
  • D7169 GC Distillation
  • IP 501 Metals
  • P-Value (Peptization of Asphaltenes in Oil)





Common Project Types
This unit has been used for both the generation of process data and also the production of samples (ranging from several liters to multiple drums) which can include:

  • Unit P2:
    • Determination of the coil inlet temperature that leads to fouling
    • Generate design data to support commercial scale up
    • Production of drum quantities for subsequent pilot plant testing
  • Unit P3:
    • Determination of the coil inlet temperature that leads to fouling
    • Feedstock screening
    • Process condition evaluations
    • Production of liter quantities for characterization
 
Need help or have a question? +1 800 967 5352
 

Need help or have a question?

+1 800 967 5352
UK/EIRE:
+44 1372 370900
S. AMER:
+55 11 2842 0444
APAC:
+86 400 886 9926
EMEA:
+46 8 750 0000
Germany
+49 711 27311 152
UAE
+971 4 317 8777