Investigation of biomass powder as a direct solid biofuel in combustion engines: Modelling assessment and comparisons

Early studies have shown that biofuels in powder form burn like a gas. In addition, they are less pollutants and renewable source. In this study, powder biofuel is investigated as a direct solid fuel in internal combustion engine. The biofuel is applied in a cylindrical shape and micron-size, with length between 75–5800 μm and diameter 30–1380 μm. Several mathematical models were investigated including different stages of biomass powder combustion in the engine. The mathematical models include drying, shrinkage, and volatilization processes. The modelling tools also investigated the movement of the fuel powder in the cylinder upon injection, how it is distributed, and its performance before combustion. The proposed models are simulated using computational fluid dynamics (CFD) tools and validated against experiments. The results showed that all models can represent the biomass powder combustion reasonably. However, some models are least expensive in calculations and time. Results also displayed that the powder are traced in different groups based on sizes and flow responses and that takes about 0.2 s. The biomass powder gasification is completed at temperature 1050 K and extra temperature has no meaning.