Numerical simulation of biomass syngas combustion

Abstract

The aim of this work was to comparatively assess the environmental characteristics of combustion products in the combustion of synthetic gas with air compared to the combustion of methane with air. Such characteristics have been so far studied for the use of methane as a fuel to a greater extent than for synthetic gases. Syngas was represented by products of a steam biomass gasification (agricultural residues). Numerical simulation of combustion processes was carried out using the kinetic model of a perfectly stirred reactor. The influence of the residence time of the chemically reacting mixture in the reaction volume on the completion of combustion processes and the emission of CO2 and NOx was investigated. For the same thermal power of the energy device, CO2 and NOx emissions from the syngas combustion exceed those from the methane combustion. Mass emission ratios were the following: CO2(syngas)/CO2(metane)≈1.55-1.57; NOx(syngas)/NOx(metane)≈2.56-3.4. The greatest impact on NOx emissions during syngas combustion is caused by higher combustion temperatures compared to the temperatures during methane combustion. To reduce NOx emissions when using syngas, it is necessary to develop and implement technical solutions that are more effective than those currently used for organizing the processes of mixture formation and combustion in energy setups.