Behavior of Beech Sawdust during Densification into a Solid Biofuel

Abstract

Abstract:In solid biofuel manufacture technological and material variables influence the densification process and thus also the final briquette quality. The impact of these technological variables, especially compression pressure and compression temperature, and also of the material parameters (particle size and moisture content) can generally be observed during biomass densification in the quality indicators, where the abovementioned variables have a significant influence, especially on the mechanical indicators of quality (briquette density, mechanical durability, etc.). This paper presents the results of experimental research dealing with determining the relationship between the technological and the material variables during densification of beech sawdust. The main goal of the paper is to determine the mutual interaction between compression pressure, compression temperature and material particle size. Research findings were obtained using single-axis densification. The influence of the particle size interacting with compression pressure and compression temperature on the final briquette density was determined. The research findings obtained should prove valuable in briquette production and also in the engineering of densification machines.

Process and Energy Analysis of Pelleting Agricultural and Woody Biomass Blends

“…The process a-b-c-d is represented by the compaction curve (a-d), which includes the work required to transfer biomass into the die (a-b), to tamp down the biomass at a lower punch (pre-compaction zone, b-c), and to consolidate the biomass, taking into account the friction (c-d). The pressure of 159 MPa and temperature of 80 • C in the die caused the particles to bond together due to natural adhesion processes [12,21,23]. It should be noted that in this study no adhesives were used while pelletizing biomass.…”

“…It is important to mention that the moisture content of the material is one of the crucial factors for the optimal compaction. During pelleting, heat is supplied (which is mainly from frictional heat developed in the die) to form a pellet and therefore, the biomass requires certain amount of moisture to bind the particles so that the pellet is compacted and retains its binding formation [21]. HHV = Higher heating value, RCG = reed canary grass, TH = timothy hay, SW = switchgrass, S = spruce, P = pine, MC = moisture content, VM = volatile mater, FC = fixed carbon (FC = 100-ash-VM-MC), trace (<1%).…”

Characterization and Production of Fuel Briquettes Made from Biomass and Plastic Wastes

“…Table 2 also shows the values of the net calorific value of the briquettes formed, in MJ kg −1 , which will be later compared to usual fuels. Despite the fact that moisture has an important effect in the densification and durability of the final briquettes [43,44], this parameter has not been modified in order to not increase the briquetting process costs, so the moisture values of the used materials are those shown in Table 1. …”

Characterization and Production of Fuel Briquettes Made from Biomass and Plastic Wastes

“…In spite of the fact that moisture has an important effect in the densification and durability of the final briquettes [43,44], this parameter has not been modified in order to not increase the briquetting process costs, so the values of moisture of the used materials are those shown in Table 1. …”