Large amounts lignocellulosic biomass in the form of straw is leftover after wheat harvesting that could be utilized for beneficial purposes. The latter has led to the emergence of new technologies to make use of this resource. One such technology currently in use turns wheat straw into briquettes. In the present study, we have prepared and evaluated the physical, mechanical and calorific properties of two types of briquettes made of wheat straw. The two types of briquettes prepared were (i) hollow briquettes and (ii) solid briquettes. The densities of these briquettes obtained on a mechanical device with a crank mechanism were 1.169 kg/m3, irrespective of whether the briquettes were hollow or solid. The briquette densities are consistent with European standards. The calorific value of wheat straw was 17.69 MJ/kg. Although the calorific value was somewhat lower than the beech wood briquettes (18.38 MJ/kg), it is adequate for their combustion in both stoves and thermal power plants. The ash content of wheat straw was 9.1% (~10-fold higher than that of beech wood). The briquettes showed a compressive mechanical strength of 1.15–2.17 N/mm2 and splitting mechanical strength of 0.17–0.39 N/mm2 suggesting that the straw briquettes were well compacted and can be stable during transport and/or other manipulations. In conclusion, wheat straw briquettes have similar physical, mechanical and calorific properties to those prepared from beech wood biomass and are a viable solution to replace beech wood briquettes with similar efficiency.

Fast-growing species have been increasingly developed in recent years, and among them, those cultivated to obtain combustible woody biomass have shown rapid development. The purpose of this research study is to highlight the properties of the briquettes and pellets obtained from energetic willow compared to the briquettes and pellets obtained from oak biomass. Methodologies have been based on international standards and were used to find the physical, mechanical, and calorific properties of the two types of briquettes and pellets. The results did not highlight a significant difference between the two categories of briquettes and pellets obtained from the two hardwood species (energetic willow and oak). Characteristics such as the calorific value were 20.7 MJ/kg for native pellets and 21.43 MJ/kg for torrefied pellets of energetic willow, as well as the compressive strength of 1.02 N/mm2, surpassed the same characteristics of briquettes and pellets obtained from oak biomass. Other characteristics of energetic willows, such as energetic density of 18.0 × 103 MJ/m3, splitting strength of 0.08 N/mm2, shear strength of 0.86 N/mm2, and abrasion of 1.92%, were favorably related to the oak biomass. The ecological analysis highlighted the high potential of the ecological willow in a period when the quantities of carbon dioxide released into the atmosphere by human activities are very high, and its sequestration by existing forests is insufficient. As a general conclusion of this research study, it can be stated that the two categories of briquettes and pellets obtained from the woody biomass of the energetic willow and oak species have similar characteristics, which can be used separately or together in ecological and sustainable combustion.