Models for Lignocellulose Thermochemical Conversion

Chemicals, fuels and energy must be produced from lignocellulosic plant-matter if global economies are to decarbonise.

To be successful, these lignocellulose-derived products must compete in technical quality and price with fossil derived products.

Thus, we must understand what lignocellulose is, and how its chemical structures react in thermochemical processing technologies, such as pyrolysis.

Pyrolysis is a promising method to produce valuable products from lignocellulose and the basic fundamental process of more complex thermochemical technologies, such as catalysis. Mod-L-T deciphers the elementary reaction mechanism and kinetics of lignocellulose pyrolysis.

Relative to cellulose, the reaction kinetics of hemicellulose and lignin are less studied, and thus the focus of Mod-L-T.Mod-L-T creates the first detailed, elementary, mass- and energy-conserved chemical reaction model for lignocellulose pyrolysis.

A compositional characterisation and modelling procedure utilising Nuclear Magnetic Resonance spectroscopy identifies what molecular structures comprise, and best represent actual lignocelluloses.

The mechanism and kinetics of the pyrolysis reaction of the identified hemicellulose and lignin functionalities are then rigorously and systematically determined by the study of model molecules of incrementally increasing structural complexity, up to actual hemicellulose and lignin structures.

Experimental and theoretical means are coordinated; A Thin Film Reactor obtains kinetically limited isothermal reaction rate and time-resolved evolved species information. Potential Energy Surfaces are determined by the M06-2X/6-311++G(d, p) methodology.

This new fundamental knowledge is assimilated by the construction of detailed reaction kinetic models for hemicellulose, lignin and lignocellulose pyrolysis.

The knowledge is disseminated for application in optimized and reduced models, envisaging their coupling to process and fluid dynamic engineering modelling tools.