Background. Composite types of biofuels used to generate energy based on fossil fuels with the addition of waste that has a significant organic component are an important area of research in the context of resource conservation and waste management. Lignin plays an important role in the process of briquetting, acting as a natural binder. Research shows that it is possible to combine different types of semi-finished products, such as sawdust and agricultural waste, without using primary resources, which can help to eliminate their individual drawbacks and improve the characteristics of the final product.
Materials and methods. The study has been conducted on the basis of a laboratory analysis of fuel briquettes that consist of a mixture of coniferous sawdust and organic waste from rabbit farming. The biofuel briquettes have been formed using an extrusion press. The wood component of the mixture has been subjected to primary drying, grinding, heat treatment, and homogenization. A comprehensive analysis of key characteristics, including moisture content, bulk density, compressive strength, calorific value, and ash content, has been conducted to evaluate the quality of samples with varying biomass content ranging from 0 to 40 %. Statistical data processing has been performed using the Loginom Community analytical platform.
Results. A laboratory analysis of the key characteristics of fuel briquettes made from a mixture of coniferous sawdust and organic waste of rabbit farming has been carried out. It has been experimentally established that the content of biomass has a significant effect on the properties of briquettes. The calorific value increases with an increase in the proportion of biomass up to 25–30 %. The compressive strength reaches a peak value at 20 %, after which it decreases due to deformation of the homogeneity of the structure; the ash content decreases consistently from 4,5 % (0 % biomass) to 1,8 % (40 % biomass) due to the low content of minerals in organic waste. The moisture content of the raw material and the bulk density increase with the increase in the proportion of biomass, which has a positive effect on compaction. Statistical analysis has revealed a direct correlation between the biomass content, moisture content, and calorific value, as well as an inverse correlation between the biomass content and ash content. The best balance between high energy performance and satisfactory strength characteristics is achieved in the range of 20–25 %.
Conclusions. Based on the conducted research, the optimal content of biomass (organic waste from rabbit farming) in a combined fuel briquette has been determined in case of a significant reduction of the ash content of the product. The developed formulation and technology allow for the production of solid biofuel with improved operational and environmental properties, which is suitable and convenient for practical use.