Detailed Modeling of Kraft Pulping Chemistry. Delignification

Abstract

This work introduces a phenomena-based model for delignification in the kraft pulping process. The solubilization of lignin is described as a set of chemical reactions representing the entire chemistry of lignin degradation as well as dissolution of the degraded lignin. For modeling, reaction mechanisms and reactions kinetics derived mainly from the literature were used. Each reaction was simulated separately and then combined for the overall degradation. The model was validated with experimental results from pine wood meal pulping under a wide range of reaction parameters. The experimental data presented a good fit with the model. With the aid of the model, the structure and the amount of wood components, in fibers and black liquor, can be determined at any pulping stage. Several engineering parameters can be computed from the detailed chemical composition of liquor and wood or chemical pulp. These include, e.g., kappa number, brightness, yield, active alkali, effective alkali, sulfidity, and higher heating value.

Deep Eutectic Solvents for the Valorisation of Lignocellulosic Biomasses towards Fine Chemicals

“…The subsequent step, after the pretreatment, can be the fermentation of sugars to produce biofuels (ethanol and butanol). Chemical pulping for producing pure cellulose in paper mills is not appropriate to this aim since inhibitors are typically released, and the subsequent demolition of cellulose can be carried out only after an expensive washing, generating a large amount of waste and wastewater [11].…”

A Review on the Modeling, Control and Diagnostics of Continuous Pulp Digesters

“…It was able to follow the trajectory of the cook with higher accuracy, given that good adjustments of its parameters were performed. Recently, Fearon et al [59] studied phenomena-based detailed modeling of the delignification process by considering macromolecular aspects of lignin. Concurrently, Fearon et al [60] also studied the detailed chemistry and essential phenomena of carbohydrate reactions at the molecular level.…”

Detailed modeling of the kraft pulping chemistry: carbohydrate reactions

“…In the present paper, carbohydrate reaction model in kraft pulping conditions is discussed. In our other recent work, 30 the general idea of the model and the details of modeling lignin reactions were presented.…”

“…The present model, taking advantage of fundamental understanding of the identified reactions and can be applied to optimize the pulp production process. The current paper focuses on hemicellulose reactions in kraft pulping and Fearon et al 30 paper focuses on delignification model in kraft pulping.…”