Stochastic Reactor-Based Fuel Bed Model for Grate Furnaces

Corinna Netzer,Terese Løvås,Fabian Mauß,Tian Li,Lars Seidel

doi:10.1021/acs.energyfuels.0c02868

Abstract

Biomass devolatilization and incineration in grate-fired plants are characterized by heterogeneous fuel mixtures, often incompletely mixed, dynamical processes in the fuel bed and on the particle s...

Highlights

The combustion of biomass has the potential to generate renewable energy and heat supply from locally available resources
Moving grate-firing systems are widely applied to burn biomass since they have a simple construction and process control. They offer the needed flexibility toward varying fuel and have low investment costs.[1]. The drawback of this diverse use of technology is unoptimized incineration that leads to unwanted emissions, such as dust and nitrogen oxides (NOx), as well as incomplete combustion products, such as carbon monoxide (CO), unburned hydrocarbons (HCs), and polycyclic aromatic hydrocarbons (PAHs) that can become soot particles.[2,3]
The model is tested using a pyrolysis case and two fuel beds in grate-fired plants from the literature that vary in complexity of the constructed reactor network and ignition type

Summary

■ INTRODUCTION

The combustion of biomass has the potential to generate renewable energy and heat supply from locally available resources. The gas-phase chemistry is solved as described in previous studies,[53,61] and the heterogeneous reactions are discussed elsewhere.[53,62] In the operator splitting loop, two processes are based on random seed generation: the selection of stochastic particles for mixing and the heat transfer with the wall The results of the fuel bed reactor network and the subsequent CFD simulations using the predicted released gas composition from the network as inlet conditions are discussed for different loads. The variations in temperatures and available solid fuel and oxygen result in very flat distributed PDFs for tar species and other released gases, such as CH4 and CO, and to a very heterogeneously composed gas phase.

■ CONCLUSIONS

■ ACKNOWLEDGMENTS

■ REFERENCES