Crude Preheat Curramix Coating 2-Year Projection

Following up to Study 1, for coated cases, evaluate cleaning at a 2 year frequency instead of 1 year. Quantify the benefits from the longer run length (avoiding one cleaning). Include credits for avoiding the maintenance cost and potential rate cuts required for cleaning.

This study evaluates a Crude preheat exchanger service heat transfer performance with the following tube material and coatings and estimates the energy savings and CO2 Emissions Reduction:

• Carbon Steel
• Stainless Steel
• Carbon Steel Tube ID Coated
• Stainless Steel Tube ID Coated

• Service – Desalted Crude vs Heavy Vacuum Gas Oil (HVGO)
• Tube ID Coating Thickness – 25 Microns (0.001 inch)
• Coating Thermal Conductivity – 0.722 Btu/hr-ft-F
• Fuel Value -$3.50 per MBtu/hr
  [Note fuel prices in Asia can be 3X compared to US]
• Furnace Efficiency = 0.9
• Network Factor = 0.75
  [Part of the Duty Gain in the Exchanger Diminishes Heat Transfer on other Exchangers in the Preheat Train due to changes in temperature differentials]
• CO2 Reduction based on EPA Conversion Equations
• Heat Transfer Calculation performed with HTRI XIST
• Assumed Fouling Factor shown in the Comparison Tables below
• Coated bundles are cleaned at 2 year frequency
• Non coated bundles are cleaned yearly
• Assumed Inlet Operating
  • Crude Inlet Temp – 370 F
  • Crude Rate – 650 klb/hr
  • HVGO Inlet Temp - 505 F
  • HVGO Rate – 675 klb/hr
• 7 Days Oil Out to Oil In for Exchanger Cleaning
• Maintenance Cost for Cleaning - $40k
• Margin Cost Per Day During Cleaning – Approx $15k per day

Heat Exchanger Geometry

• TEMA – AES
• Shell Id = 50”
• 1054 Tubes
• 1” Tube OD
• 083” tube wall thickness
• 4 Tube Passes
• 20 ft length
• 11 Baffle Cross Passes, Single Vert Seg , 20.9% Cut

Comparison Tables

Coated Carbon Steel (cleaned 2yr interval) Versus Carbon Steel (cleaned yearly)

• Annualized Duty Reduction = 0.6 MBtu/hr
• Energy benefit = $28k over 2 years
• Margin + Maintenance benefit from increasing cleaning interval = $105k+$40k=$145k
• CO2 Equivalent Benefit = 423 Tons over 2 years
• Overall Benefit = $28k + $145 k = $173k

Coated Stainless Steel Versus Stainless Steel

• Annualized Duty Reduction = -0.9 MBtu/hr
• Energy benefit = -$46.8k over 2 years
• Margin + Maintenance benefit from increasing cleaning interval = $96.8k+$40k=$136.7k
• CO2 Equivalent Increase Emissions = 708 Tons over 2 years
• Overall Benefit = -$46.8k + $136.7k = $89.9k