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Every Kraft pulp mill runs on spreadsheets. Dozens of them — one for steam balance, one for chemical cost, one for the recovery boiler, none of them connected. Change the kappa target and you manually update four files. Miss one and the numbers lie.

This book replaces that stack with a single Python model.

Digital Twin for Kraft Pulp Mills in Python is a complete, process-flow-ordered simulation of a softwood Kraft mill — from wood yard to baled pulp, from fiber balance to EBITDA. Every module is connected. Change one parameter and the full mill recalculates in milliseconds: steam balance, chemical consumption, power export, cash cost per ADt, and CapEx payback — all at once.

The model is calibrated to a 1,217 ADt/d NBSK reference mill and validated against real operating data. The furnish is fully configurable — switch softwood to hardwood or mixed furnish by changing two parameters.

WHAT'S INSIDE

70 connected modules (M0–M69), 2,250 tests, all passing
MCC 2-vessel digester with H-factor and sulfidity correction
DD washer system with Norden efficiency and washing optimizer
D-EOP-D ECF bleach sequence with ClO2 generator model
Recovery boiler, two-unit evaporator, lime kiln with green H2 option
Two-pressure turbine power model using live IAPWS-IF97 steam tables
Variable cost, fixed cost, EBITDA, and CapEx payback with IRR
Calibration engine, Monte Carlo risk analysis, and OEE calculator
Annual two-season plan for production and power export

WHO THIS BOOK IS FOR

Process engineers, mill managers, and technical consultants who need to run \"what-if\" scenarios faster than a spreadsheet allows — and understand exactly why the numbers change.

No prior Python experience is required beyond the ability to run a script. If you can read a process flow diagram, you can use this model.

LIVING BOOK

This is a living book. All future updates are delivered automatically to purchased copies through Leanpub at no extra charge.

Planned additions include a hardwood kraft deep module, a Streamlit UI dashboard, and multi-mill comparison tools.

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Kick off your book project, get started with GhostAI, get better at marketing, or spend the day doing all three! Free live workshops on Zoom. Saturday, June 27, 2026.

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