A kinetic reaction model for biomass pyrolysis processes in Aspen Plus

Abstract

This paper presents a novel kinetic reaction model for biomass pyrolysis processes. The model is based on the three main building blocks of lignocellulosic biomass, cellulose, hemicellulose and lignin and can be readily implemented in Aspen Plus and easily adapted to other process simulation software packages. It uses a set of 149 individual reactions that represent the volatilization, decomposition and recomposition processes of biomass pyrolysis. A linear regression algorithm accounts for the secondary pyrolysis reactions, thus allowing the calculation of slow and intermediate pyrolysis reactions. The bio-oil is modelled with a high level of detail, using up to 33 model compounds, which allows for a comprehensive estimation of the properties of the bio-oil and the prediction of further upgrading reactions. After showing good agreement with existing literature data, our own pyrolysis experiments are reported for validating the reaction model. A beech wood feedstock is subjected to pyrolysis under welldefined conditions at different temperatures and the product yields and compositions are determined. Reproducing the experimental pyrolysis runs with the simulation model, a high coincidence is found for the obtained fraction yields (bio-oil, char and gas), for the water content and for the elemental composition of the pyrolysis products. The kinetic reaction model is found to be suited for predicting pyrolysis yields and product composition for any lignocellulosic biomass feedstock under typical pyrolysis conditions without the need for experimental data.

Modeling the valorization of poultry litter via thermochemical processing

“…Non‐conventional biomass feed was broken into simulation components, which were the basic biomass constituents: cellulose, hemicellulose and lignin. Following the approach taken by Peters et al ., hemicellulose and cellulose were represented in the simulation by their monomers, C 5 H 8 O 4 (xylan) and C 6 H 10 O 5 (xylose‐like cellulose monomer), lignin was represented by a phenyl propane monomer. Further details of the pyrolysis methodology (component selection, flow diagram and process description) used in this study have been discussed elsewhere .…”

Assessment of low‐rank coal and biomass co‐pyrolysis system coupled with gasification

“…Two methods have been mainly used in the previous literature to determine the yields of pyrolysis products: one of these methods is based on experiments, whereas the other is a theoretical method. 35,36 Given the natural complexity of the coal pyrolysis reaction, the kinetic reaction model is usually very complex and difficult to use in practical applications. Therefore, the experimental-databased method is often used in investigating the pyrolysis process in ASPEN plus.…”

Biogeochemical potential of biomass pyrolysis systems for limiting global warming to 1.5 °C

“…However, higher HTTs lead to more None none recalcitrant biochar, resulting in longer mean residence times when applied to soil (Zimmerman et al 2011. For the purpose of the present study, we selected a standard so-called rotary kiln type slow pyrolysis system with a HTT of 450 • C and no reactive or inert gas injection (Fagernäs et al 2012, Peters et al 2017). The selected pyrolysis parameters (table S1) are a reasonable compromise between a rather high biochar yield (55% of the initial biomass carbon) with extended biochar mean residence times in soils (>750 years, (Camps-Arbestain et al 2015, ) at medium bio-oil yields (34% of biomass carbon) and a low permanent-pyrogas yield (21% of biomass carbon) (Neves et al 2011).…”