# Techno-Economic Assessment of Two Process Routes for Lignin-Derived Alkylphenols and Aromatic Hydrocarbons

## TL;DR

This study compares two methods for converting lignin into valuable chemicals, finding that combining HydroThermal Liquefaction with HydroDeOxygenation is more efficient and cost-effective.

## Contribution

The study introduces a techno-economic comparison of HDO and HDO + HTL for lignin valorization, highlighting the economic superiority of the integrated process.

## Key findings

- The HDO + HTL process achieves higher alkylphenol yields (30–35% by weight) and uses less hydrogen (22–28 kg H2/ton lignin).
- The minimum selling price of alkylphenols via HDO + HTL is 1.52 EURO/kg, less than half of the 3.47 EURO/kg via HDO.
- Lignin market price significantly affects alkylphenol selling prices, with variations exceeding 1 EURO/kgAP.

## Abstract

Lignin valorization processes are crucial for enhancing
the economic
feasibility of lignocellulosic biorefineries and improving waste management
in the pulp and paper industries. This study performed a detailed
techno-economic evaluation comparing two alternative lignin conversion
pathways, focusing on the production of aromatics and alkylphenol:
HydroDeOxygenation (HDO) and HydroDeOxygenation are preceded by HydroThermal
Liquefaction (HDO + HTL). The analysis revealed that the integrated
HDO + HTL is technically and economically superior, since it provides
higher alkylphenol yield (30–35% by weight) and requires significantly
less hydrogen, consuming only 22–28 kg of H2 per
ton of lignin. As a direct consequence of the superior yield and lower
reagent consumption, the minimum selling price of alkylphenols via
HDO + HTL is less than half of that obtained via HDO (1.52 compared
to 3.47 EURO/kg, respectively). A comprehensive sensitivity analysis
demonstrated that the lignin market price has the greatest impact
on the minimum selling price of alkylphenols, resulting in variations
of more than EURO 1/kgAP. Even under the most favorable
economic conditions for direct HDO (low hydrogen cost and free lignin),
the HTL + HDO configuration remained the most economically convenient
process solution. The results affirm that coupling HTL with HDO maximizes
product yields and minimizes costs, securing profitability for lignin
valorization