Module 5 - Product Quality

Module from the Hydroprocessing Operations Curriculum curriculum.

PRODUCT QUALITY & LAB CORRELATION · Learning Objectives · 1. Define ULSD product specifications and regulatory requirements 2. Correlate operating conditions to product quality (sulfur, nitrogen, cetane, pour point) 3. Interpret lab results and identify trends requiring corrective action 4. Troubleshoot off-spec product situations 5. Manage product routing during upset conditions · ULSD Product Quality Targets vs Regulatory Limits

Property	ASTM Method	EPA Limit	Typical Target	Pipeline Spec	Off-Spec Action	Control Lever
Sulfur	D5453 (UV fluorescence)	15 ppm max	8-12 ppm	15 ppm	Increase WABT 5-10°F, verify H2 purity	Reactor temperature (WABT)
Nitrogen	D4629 (chemiluminescence)	No EPA limit	<10 ppm	Not specified	Increase WABT, increase H2/oil ratio	Temperature + H2 partial pressure
Cetane Number	D613 (CFR engine)	40 min	45-52	40 min	Increase severity (more aromatic saturation)	H2 pressure, WABT, residence time
Cetane Index	D4737 (calculated)	40 min	43-50	40 min	Correlates with cetane number but not exact	Feed quality + severity
Cloud Point	D2500	Seasonal (-20 to +5°F)	Meet seasonal limit	Per pipeline spec	Adjust cut point, add cold flow improver, increase severity	Fractionation cut point, severity
Distillation (T90)	D86	640°F max (No. 2-D)	600-630°F	640°F	Reduce diesel endpoint, increase stripper severity	Fractionation, stripper steam
Flash Point	D93 (Pensky-Martens)	125°F min (No. 2-D)	140-160°F	125°F	Increase stripper steam, check for light ends contamination	Stripper operation
Color	D1500 (ASTM Color)	Not regulated	1.0-2.0 max	3.0 max	Indicates poor aromatic saturation or feed contamination	Severity, feed quality
Lubricity (HFRR)	D6079	520 μm max	300-400 μm	520 μm	Add lubricity improver (fatty acid ester)	Additive injection (post-treating)
Source: FOS Chief Files — Lab Methods folder, Refinery_Product_Specifications_v1.xlsx, ASTM D975 standard

Source: Hydroprocessing_Operations_Curriculum_v1.xlsx · Sheet: Module 5 - Product Quality

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