Species transport modeling and tar analysis in palmyra palm fruit nutshell gasification: Performance evaluation and process optimization

This study used numerical methods with a species transport model that includes tar cracking reactions to investigate the gasification of palmyra palm fruit nutshell (PPNS). The two-dimensional computational fluid dynamics (CFD) model of a downdraft gasifier accounted for the drying, pyrolysis, oxidation, and reduction zones. The experimental data, focusing on the influence of equivalence ratio (ER) and moisture content on the gasifier’s performance, validated the model. For the optimal performance, the ER, peak calorific value, cold gas efficiency, and carbon conversion efficiency were 0.35, 6.90 MJ/Nm³, 71.07 %, and 79.18 %. Increasing the moisture content from 10 % to 18 % led to an 11.5 % reduction in calorific value and a decrease in carbon conversion efficiency. Additionally, both experimental data and CFD simulation results confirmed that the optimal ER for PPNS gasification is 0.35. The CFD model accurately predicted the temperature profiles, gas composition, and tar formation, with benzene being the most abundant tar compound.