PRELIM - Petroleum Refinery Life Cycle Inventory Model

A Python library for modeling petroleum refinery processes and calculating life cycle inventories and environmental impacts.

Converted from PRELIM_v1.6.xlsm Excel model.

Overview

PRELIM is a comprehensive model for petroleum refineries that:

• Models 650+ crude oil assays with detailed properties
• Simulates major refinery process units (CDU, VDU, FCC, Coker, Hydrotreaters, etc.)
• Calculates energy requirements and emissions
• Performs life cycle impact assessment using TRACI 2.1
• Supports custom crude oil blending
• Enables batch processing across multiple assays

Installation

# Clone or download the repository
cd Prelim

# Install in development mode
pip install -e .

# Or install dependencies directly
pip install -r requirements.txt

Quick Start

from prelim import Refinery

# Create a refinery model
refinery = Refinery()

# Set crude oil assay
refinery.set_crude_assay('Alaskan North Slope_Exxon')

# Configure refinery parameters
refinery.configure(capacity_bpd=150000)

# Run calculations (when implementation complete)
results = refinery.run()

Features

Crude Oil Assays

Access 650+ crude oil assays with complete distillation curves and properties:

from prelim.data.assays import get_assay_inventory

inventory = get_assay_inventory()

# Search for assays
alaska_crudes = inventory.search_assays('Alaska')

# Get assay properties
assay = inventory.get_assay('Alaskan North Slope_Exxon')
api_gravity = assay.get_property('API gravity', 'Full Crude')
sulfur = assay.get_property('Sulfur', 'Full Crude')

Crude Oil Blending

Create custom crude blends using weight-averaging:

from prelim.core.crude_blending import create_custom_blend

blend = create_custom_blend(
    crude_names=['Alaskan North Slope_Exxon', 'Arab Light_Saudi Aramco'],
    fractions=[0.6, 0.4],  # 60% Alaska, 40% Arab Light
    refinery_capacity_bpd=100000
)

Life Cycle Assessment

Build life cycle inventories and calculate environmental impacts:

from prelim.lca.inventory import LifeCycleInventory
from prelim.lca.impact_assessment import assess_refinery_impacts

# Create inventory
inventory = LifeCycleInventory("Refinery Process")
inventory.add_emission('Carbon dioxide', 'air', 1000.0, 'kg')
inventory.add_emission('nitrogen oxides', 'air', 2.5, 'kg')

# Calculate impacts
impacts = assess_refinery_impacts(inventory)
print(f"Global Warming: {impacts['kg CO2 eq / kg']:.2f} kg CO2 eq")

Batch Processing

Run calculations across multiple crude assays:

from prelim.core.batch_processor import BatchProcessor

processor = BatchProcessor(refinery_model)
results = processor.process_all(max_assays=10)

# Export results
df = processor.get_results_dataframe()
df.to_csv('batch_results.csv')

Project Structure

prelim/
├── __init__.py
├── data/                      # Data modules
│   ├── constants.py           # Refinery constants and parameters
│   ├── assays.py              # Crude oil assay data (654 assays)
│   ├── emission_factors.py    # Emission factors
│   ├── traci_factors.py       # TRACI 2.1 characterization factors
│   ├── process_correlations.py # Process correlations
│   └── energy_conversions.py  # Energy and unit conversions
├── core/                      # Core calculation modules
│   ├── refinery.py            # Main Refinery class API
│   ├── calculations.py        # Calculation graph engine
│   ├── process_units.py       # Process unit models
│   ├── crude_blending.py      # Crude blending (from VBA)
│   └── batch_processor.py     # Batch processing (from VBA)
├── lca/                       # Life cycle assessment
│   ├── flows.py               # Elementary flow definitions
│   ├── inventory.py           # Life cycle inventory
│   └── impact_assessment.py   # LCIA with TRACI 2.1
└── utils/                     # Utilities
    ├── excel_reader.py        # Excel data extraction
    └── validators.py          # Validation against Excel

tests/                         # Test suite
examples/                      # Usage examples

Examples

See the examples/ directory for detailed usage examples:

• basic_usage.py - Basic refinery modeling workflow
• crude_blending.py - Custom crude blend creation
• lca_example.py - Life cycle assessment

Development Status

The Python library framework is complete with:

• ✅ Data extraction from Excel (all sheets)
• ✅ Crude assay loading and management (654 assays)
• ✅ Crude blending (converted from VBA)
• ✅ Calculation engine framework
• ✅ Process unit model structure
• ✅ Batch processing (converted from VBA)
• ✅ LCA modules with TRACI 2.1
• ✅ Validation framework
• ✅ Comprehensive test suite

In progress:

• 🔄 Detailed process unit calculations (100K+ Excel formulas)
• 🔄 Full validation against Excel outputs

Testing

Run the test suite:

pytest tests/ -v

Dependencies

• pandas >= 2.0.0
• openpyxl >= 3.1.0
• numpy >= 1.24.0

Contributing

This project is converted from the PRELIM Excel model. For questions about the underlying refinery model and assumptions, please refer to the original PRELIM documentation.

Citation

If you use PRELIM in your research, please cite the original PRELIM model:

[Add appropriate citation for PRELIM_v1.6.xlsm]

License

TBD