Materials for making fuel briquettes

Biomass briquettes, serving as an alternative to fossil fuels, have become a frequently utilized energy source in developing countries due to their renewable, environmentally friendly, and highly available nature. Utilizing fuel briquette presses, a range of biomass materials can be compressed under pressures ranging from 49 to 196 MPa into dense briquettes of various shapes, suitable for fueling boilers, stoves, furnaces, and other applications. Currently, the production of biomass briquettes is scaled up significantly to meet energy demands and offer a viable solution for waste management. Nevertheless, given the diversity of biomass materials, several factors need to be carefully examined to assess their suitability as feedstock for briquette production.

Availability

Availability is a crucial factor in establishing a biomass fuel briquette plant, as it directly determines the productivity of the briquettes. Apart from the availability of raw materials, several other factors also need to be taken into consideration.

Moisture content

Moisture content is a pivotal factor that significantly affects the quality of biomass briquettes. Generally, a lower moisture content translates into higher quality briquettes, with an ideal range typically falling between 8% and 15%. Materials with higher moisture content must be dried prior to processing in fuel briquette presses, as excessive moisture can damage the presses or prevent the formation of briquettes.

Ash content

Ash content is a crucial standard that quality biomass briquettes must meet. High ash content in biomass residues can lead to devolatilization during combustion, resulting in slagging and deposition. This can damage boilers, stoves, and other equipment due to the presence of alkaline minerals like potash. The ash content of various biomass materials is indicative of the slagging potential of the briquettes. Typically, a higher ash content leads to increased slagging. In addition to ash content, factors like operating temperature, ash composition, and percentage contribute to slagging. Generally, slagging occurs when the ash content of biomass exceeds 4%. The presence of SiO2, Na2O, and K2O can further exacerbate the problem, serving as indicators of briquette quality. Based on these factors, fuels can be classified as causing severe or moderate slagging.

Flowability

The materials must possess flowability, as finely milled particles need to flow smoothly through bunkers and storage silos. Excessive stickiness can pose challenges for the fuel briquette presses, necessitating the selection of materials that are suitable for efficient processing.