Pyrolysis and combustion characteristics and kinetics of wood sawdust and wood sawdust hydrochar

Abstract

This study compares the pyrolysis and combustion characteristics with the kinetics of wood sawdust and its hydrochar. Wood sawdust hydrochar was obtained by the hydrothermal treatment of wood sawdust (biomass/water: 1 g/4 mL) at 220°C, where the residence time was set as 90 min. After hydrothermal carbonization, carbon content and heating value were both increased by 14%. Pyrolysis and combustion of wood sawdust and its hydrochar were performed by thermogravimetric analysis at 10, 20, 30, and 40°C/min. Kissinger–Akahira–Sunose (KAS) method, Friedman method, Flynn–Wall–Ozawa (FWO) method, and Kissinger method were used for analyzing the pyrolysis data. For combustion, only KAS and FWO methods were used to determine the kinetic parameters. As compared to wood sawdust pyrolysis, average activation energy of hydrochar pyrolysis was lower (150.36 kJ/mol by using KAS method, 153.05 kJ/mol by using FWO method). Based on mean activation energies, pyrolysis reaction of hydrochar was more favorable than its combustion. In combustion, average activation energy of hydrochar combustion reaction was higher; indicating that combustion of wood sawdust was more favorable.

Effect of lanthanum cerium methionine on the properties of natural rubber

“…The vulcanizate was increased from room temperature to 800°C at three heating rates of 10°C/min, 15°C/min, and 20°C/min in an air atmosphere, using the Kissinger method and Flynn–Wall–Ozawa method to analyze the thermal-oxidative degradation of NR. 13,14 (1) Kissinger method…”

Effect of pretreatment parameters and binder concentration on the densification of wood residue

“…Pellets can be used efficiently for biochemical or thermochemical conversion due to their large surface area. The process of biomass densification is affected by pellets dimensions, percentage of binders, and pretreatment of raw biomass 15,16 …”

“…The process of biomass densification is affected by pellets dimensions, percentage of binders, and pretreatment of raw biomass. 15,16 Wood residue, one of the potential biomasses, is rarely used previously. Mechanical grinding of wood usually involves breaking the wood into smaller particles, different shapes of particles, and high specific surface area, which depends on energy and the method of grinding as well as the condition of grinding and properties of raw material.…”

Pyrolysis kinetics of hydrochar using distributed activation energy model

“…The pyrolysis kinetics of these hydrochars are based on first‐order and n th‐order Arrhenius models. Algorithms that have been used to estimate the kinetic parameters include the Coats–Redfern, Kissinger–Akahira–Sunose, Flynn–Wall–Ozawa, Friedman, and discrete‐distributed activation energy models 39–51 . Connecting these kinetics to particle‐scale models is essential to construct computational fluid dynamic (CFD) simulations, which can be used to assess and optimize reactor performance.…”

“…Algorithms that have been used to estimate the kinetic parameters include the Coats-Redfern, Kissinger-Akahira-Sunose, Flynn-Wall-Ozawa, Friedman, and discrete-distributed activation energy models. [39][40][41][42][43][44][45][46][47][48][49][50][51] Connecting these kinetics to particle-scale models is essential to construct computational fluid dynamic (CFD) simulations, which can be used to assess and optimize reactor performance. Computational fluid dynamic simulation of pyrolysis and fast-pyrolysis has been conducted in a variety of fixed-bed and fluidized-bed reactors but the pyrolysis kinetics involved were limited to lignocellulosic biomass and coal-based feedstocks.…”