Densification

Most biomass? in natural form is difficult to utilize because it is bulky, relatively wet, and due to its low bulk-density is costly to transport. Biomass densification is the compression or compaction of biomass to reduce its volume per unit area, and thereby increase its bulk density. Densification is used for solid fuel applications.

Densification is typically a 3-step process involving drying, grinding and mechanical compression (sometimes also involving steam) of biomass. During compression particles rearrange themselves to form a closely packed mass, and pressure forces the particles to undergo deformation that generates a bond of electrostatic forces. Pellets (see photo below), briquettes, logs or larger units are produced. Drying of biomass improves the grinding process, and results in smaller more uniform particles of biomass. Use of steam during the compression phase modifies the particles further and improves bonding.

Binders are sometimes used in densification. Agglomeration is the term used to describe densification with binders. Agglomeration typically involves use of powdered biomass.



(University of Illinois at Urbana-Champaign)


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Use of contour buffer strips in commodity crop systems in southwestern Wisconsin helps reduce soil loss and traps nutrients on slopes. Photo courtesy of Wisconsin Farm Bureau Federation.