PapAiEra 0.2.8

A Python library for Pulp and Paper manufacturing processes, based on BREF (Best Available Techniques) standards.

PapAiEra

PyPI Project URL: https://pypi.org/project/PapAiEra/

Installation

pip install PapAiEra

PapAiEra is a specialized Python library engineered for the Pulp and Paper industry. It mathematically models and solves optimization problems based on the Best Available Techniques (BAT) reference documents (EU BREF 2015).

---

Included Processes & Modules

The library covers a massive array of metrics across the entire pulp and paper production cycle.

1. Pulping Modules (pap_ai_era.pulping)

• Kraft (kraft.py): H-factor calculation, Digester Mass Balance, Kappa numbers, recovery efficiency, black liquor solids, yield, BAT compliance.
• Sulphite (sulphite.py): Yields for paper/dissolving grades, SO2 and Mg/Ca base recovery.
• Mechanical (mechanical.py): Energy intensity of SGW, PGW, TMP, and CTMP, heat recovery.
• Recycled Fibre (recycled.py): Deinking yield, fiber loss, rejects rates.
• Non-Wood (non_wood.py): Depithing efficiency, silica load checks (crucial for bagasse).
• Bleaching Engine (bleaching/): Universal, input-driven bleaching sequence optimizer.
• Hood Optimizer (papermaking/): Dryer hood performance and energy optimizer.
• Bulk Prediction Model (papermaking/): ML-based multi-layer sheet bulk simulator.
• Boiler Optimizer (energy/): Physics-aware Digital Twin and efficiency optimizer.
• Recovery Cycle (recovery_cycle.py): Causticizing efficiency, evaporator steam economy, lime kiln energy.

2. Papermaking Modules (pap_ai_era.papermaking)

• Machine Operations (machine.py): Paper machine fiber mass balance, OEE, broke tracking, wire retention, dryer section economy.
• Wet End Chemistry (wet_end_chemistry.py): Furnish-based dosing heuristics, physical GPL to LPH pump conversion algorithms, ash retention.
• Coating/Finishing (coating.py): Colour recovery, ultrafiltration efficiency, specific water usage.
• Variability Analysis (variability_analysis.py): ABB-compliant VPA engine for MDL, CD, and MDS decomposition.

3. Sustainability (pap_ai_era.sustainability)

• Emissions (emissions.py, air_emissions.py): BOD/COD/TSS load to water. TRS, SO2, NOx, Dust to air.
• Wastewater & Water (wastewater.py, water_energy.py): Loop closure, explicit cooling-water vs contaminated-water accounting.
• Management (EMS): ISO 14001 grading, solid waste footprint (Ash + Sludge + Rejects).
• Power Plant & Cogen (power_plant.py): Boiler thermal efficiency and TG steam tracking.

4. Mathematical AI Solvers (pap_ai_era.optimization_models)

Allows for non-linear optimization using SciPy constraints to determine optimal dosing/setpoints.

• optimize_batch_kraft_digester()
• optimize_continuous_kamyr_digester()
• optimize_bleaching_sequence_cost()
• optimize_sulphite_base_recovery()
• optimize_machine_steam_consumption()
• optimize_wet_end_dosing()
• optimize_cogeneration_tg_fuel()

---

Advanced Usage Examples

🧠 Universal Bleaching Optimizer

PapAiEra now includes a Universal Bleaching Brain. Engineers can define custom stages, chemicals, and costs via a simple JSON/dict configuration.

Key Features:

• Dynamic Sequence Building: Supports any number of stages (e.g., D0-EOP-D1, O-Z-P, etc.).
• AI-Driven Simulation: Plug-in system for Heuristic, PNN, or Regression models.
• Global Optimization: Uses Differential Evolution to minimize total chemical cost while hitting Brightness, Kappa, and Viscosity targets.

from pap_ai_era.bleaching import run_optimization_from_config

config = {
    "stages": [
        {
            "name": "D0",
            "chemicals": [{"name": "ClO2", "min_dosage": 5, "max_dosage": 30, "cost": 0.8}]
        },
        {
            "name": "EOP",
            "chemicals": [
                {"name": "NaOH", "min_dosage": 5, "max_dosage": 25, "cost": 0.4},
                {"name": "H2O2", "min_dosage": 2, "max_dosage": 15, "cost": 0.6}
            ]
        }
    ],
    "targets": {"brightness": 90.0, "kappa": 2.0, "viscosity_min": 800}
}
result = run_optimization_from_config(config)

📊 Variance Partition Analysis (VPA - ABB 2-Sigma)

Decomposes reel variability into Machine Direction (MDL), Cross Direction (CD), and Residual (MDS) components with automated root-cause inference.

import numpy as np
from pap_ai_era.papermaking.variability_analysis import compute_vpa

# 50 scans and 600 data boxes
data = np.random.normal(loc=50, scale=1.5, size=(50, 600))
vpa_report = compute_vpa(data, process_average=50.0)

print(f"Total 2-Sigma Variability: {vpa_report.normalised['TOT']:.2f}%")
print(f"Primary Problem Detected: {vpa_report.primary_problem}")

📚 ML Bulk Prediction Model

A supervised learning framework to predict paper/board bulk ($cm^3/g$) based on layer-wise furnish, pulp properties (CSF, SW/HW ratio), and pressing conditions.

Key Features:

• Layer-Wise Analysis: Handles multi-layer structures (Top, Middle, Bottom) with independent pulp blends.
• Physics-Aware ML: Combines Random Forest regression with industrial heuristics for robust predictions even with limited data.
• Process Sensitivity: Tracks the impact of Nip Load, Number of Nips, and refining (CSF) on final sheet thickness.

from pap_ai_era.papermaking import BulkModel

# Define layers and process conditions
layers = [{"gsm": 50, "sw_ratio": 0.9, "csf": 550}, {"gsm": 150, "sw_ratio": 0.1, "csf": 400}]
process = {"nip_load": 60, "n_nips": 2}

model = BulkModel(n_layers=2)
# model.train(historical_data) # Train on mill data
predicted_bulk = model.predict(layers, process)

💨 Paper Machine Hood Optimizer

Optimizes the dryer section hood by balancing evaporation load against airflow and recirculation.

Key Features:

• Drying Load Calculation: Uses production rate, speed, and moisture removal (Inlet/Outlet) to determine the exact evaporation demand.
• Energy Minimization: Optimizes Fan RPM and Recirculation to save steam and electrical energy.
• Operational Safety: Ensures the sheet reaches target dryness while minimizing heat loss to the atmosphere.

from pap_ai_era.papermaking import run_hood_optimization

params = {
    "machine_speed": 1200, "gsm": 80, "width": 6.5,
    "inlet_moisture": 42.0, "target_moisture": 5.0,
    "return_temp": 85.0, "outside_temp": 30.0, "humidity": 0.15
}
best = run_hood_optimization(params)

🔥 Universal Boiler Optimizer

A physics-aware Boiler Digital Twin that uses hybrid modeling to maximize thermal efficiency while staying within safety and emission constraints.

Key Features:

• Hybrid Modeling: Combines first-principles energy balance with ML residuals.
• Efficiency Maximization: Finds the sweet spot for fuel/air ratios to minimize stack loss and unburnt fuel.
• Constraint Safety: Automatically respects limits for O2%, steam pressure, and flue gas temperature.

from pap_ai_era.energy.boiler_optimizer import Boiler, BoilerOptimizer

config = {"boiler_type": "AFBC", "fuel": {"CV": 4200}}
boiler = Boiler(config)
optimizer = BoilerOptimizer(boiler)

# Optimize for maximum efficiency
result = optimizer.optimize(disturbances={"feedwater_temp": 110})

⚙️ Kraft Digester Vroom H-Factor

Calculates the integrated cooking reaction rate required to hit your Kappa target.

from pap_ai_era.pulping.kraft import calculate_h_factor

# 165 °C cooking zone for 45 minutes
h_factor_generated = calculate_h_factor(temperature_celsius=165.0, time_minutes=45.0)
print(f"H-Factor Generated: {h_factor_generated:.2f}")

💧 Papermaking Moisture Prediction

Simulates the entire water loss journey through the Wire formers, Press Nips, and Dryers.

from pap_ai_era.papermaking.moisture_prediction import predict_wire_drainage_and_couch_moisture

couch = predict_wire_drainage_and_couch_moisture(
    target_gsm=80, machine_speed_mpm=1200, wire_width_m=6.5,
    layer_data=[{'gsm': 40}, {'gsm': 40}],
    vacuum_boxes=[{'vacuum_kpa': 15}, {'vacuum_kpa': 35}, {'vacuum_kpa': 60}]
)
print(f"Moisture exiting Couch Roll: {couch['moisture_after_couch_pct']:.2f}%")

---

Troubleshooting Guide

1. Optimization returns success: False: Target constraints are mathematically impossible. Adjust boundaries in the bounds variables. 2. Import Errors: Ensure you run pip install PapAiEra in an active environment. 3. Data Shape for VPA: The VPA engine expects a 2D numpy array of (scans, data_boxes).