Recently, there was an increase in demand of biomass pellets as an alternative energy source. However, it is necessary to reduce the size of granular materials during the pelleting process. The size reduction of eucalyptus bark occurs in the industrial processing of biomass pellets production, using a hammer mill together with three sieve sizes of 3, 4, and 5 mm and the sieve speeds of 900, 1000, 1100, and 1200 rpm, respectively, which have been examined at a feed rate of 80 kg/h. The aims of this study were to determine the important parameters, namely rotational speed, to determine suitable sieve size for reducing the size of eucalyptus bark, and to analyze energy usage in the size reduction process by using a hammer mill. The results have shown that using a 5 mm sieve size at 900 rpm sieve speed resulted in the best operating conditions in order to offer the highest capacity and lowest specific energy consumption. Moreover, the average particle size of 0.15 mm was an acceptable value. This study could be very beneficial in the development process to produce biomass pellets.

No abstract

No abstract

This study aims to increase the quality and value of raw materials with a low higher heating value, HHV (secondary ingredients), but which is abundantly available throughout the year by mixing it with high HHV materials (main ingredients) to obtain quality and standardized charcoal products in accordance with the industrial product standards as approved for commercial use. As for the ingredients, charcoal A is Eucalyptus bark coal (EuBC) with an average HHV of 3779.98 cal/g, charcoal B is rice husk coal (RHC) with an average HHV of 4863.29 cal/g, and charcoal C is charcoal from a biomass power plant (CBPP) with an average HHV of 5991.18 cal/g. The results from the simplex-centroid mixture design method allowed increased quality and value of the biomass charcoal powder (raw material) that has a low heating value but is sufficiently available throughout the year due to the mixing of secondary ingredients with raw materials that have a high heating value (main ingredient). The charcoal briquettes production must be qualified and meet the industrial product standards, and be approved for commercial use.

The most essential components in escort farming are the determination of airflow patterns and the distribution impact of microclimate temperature variables. The objective of this study is to use Computational Fluid Dynamics (CFD) models to ascertain the aerodynamic and thermal dynamics of protected agricultural greenhouses suitable for cultivation in tropical Northeastern crops of Thailand by defining differences in greenhouse layouts, specifically Gable Roof (GR), Curved Roof (CR), Saw tooth roof (SR), and Double roof (DR). The root means square error (RMSE) indicated that the factor determination of CFD modelling using the standard k−ε turbulence model was satisfactory. In addition, they found that, at a significance level of 0.05, the average temperature in the greenhouses was statistically distinct based on the form of the back of the house and the location of the air input and outflow.