Densification

Technology
Technology details
Name:	Densification
Category:	Pre-processing (Physical processes and technologies), Post-processing (Physical processes and technologies)
Feedstock:	All materials
Product:	Biomass with increased density (e.g. pellets or briquettes)

Densification is a mechanical method to compress material with a low density, such as garden and park waste consisting of small pieces or sawdust, to consistent structures via pressure. Binder agents can be used to increase the cohesion of the particles. Densification overcomes biowaste issues with low densities, a low heating value per unit of volume, high dust levels, and a large variety in physical shapes. The process generally produces pellets or briquettes, which have a lower transportation cost and are easy to handle, which enables industrial processing. Pyrolysis and torrefaction can also be seen as forms of densification.

Feedstock

Origin and composition

Densification is used to pre-treat biomass or other materials such as wood or straw that consists of very small pieces or dust to make it available for processing or combustion. It can also be used as intermediate or final step in a process chain. Compressed compounds can contain various organic materials, including wood, straw, rice husk, bagasse, ground nut shells, municipal solid waste, agricultural waste and others.

Pre-treatment

• Drying
• Grinding

Both the drying and grinding pre-treatment are often seen as part of the densification process and therefore no additional pre-treatment is required. The biomass can be pre-heated to increase the stability and density of the pellets or briquettes.

Process and technologies

For the densification process the biomass raw materials are dried and ground. Next, the material is densified into pellets or briquettes via a pressure step. The product is then cooled, screened and bagged. For the densification step there are three main types of processes: extrusion, pelletising, and roll briquetting. In an extrusion process, the material is pushed through a screw or a piston to create small cylindrical shapes. In the pelletising process, the material is is forced through the holes of a perforated cylinder. Finally, for roll briquetting, the material falls between two rollers that rotate in opposite direction to create briquettes.

Product

Pellets made of wood

The material will leave the densification step as pellets or briquettes. Briquettes are larger and can be made from biomass with larger particles and a higher moisture content without adding a binding agent. Densification is a pre-treatment process that make biomass dust or small pieces more suitable for following processes. It also is used to compress final products like powdered charcoal to produce pellets or briquettes for burning. The most common application of the product is for domestic heating or industrial fuel.

Post-treatment

• Cooling
• Screening and bagging

Technology providers

Technology comparison

Company name	Country	Technology subcategory	Technology name	TRL	Capacity [kg/h]	Compression weight [t]	Format of densified product	Feedstock: Food waste	Feedstock: Garden & park waste
WEIMA	Germany	-	TH Series	9	-	3900	Cyclindrical, rectangular		●

CENER (ES)

Densification provider

General information
Company:	CENER BIO2C
Country:	Spain
Contact:	Goizeder Barberena, info@cener.com
Webpage:	https://www.bio2c.es/pretreatment-unit/
Technology and process details
Technology name:	BIO2C – Pelletising Plant	Technology category:	Pre-processing (Physical processes and technologies), Post-processing (Physical processes and technologies)
TRL:	6-7	Capacity:	200-700 kg/h production capacity kg·h-1
Compression weight:	not relevant t	Format of densified product:	not relevant
Size (product):	6x16 mm to 6x39 mm (LxWxH) [mm]	Other:	Ad Hoc die designs: pellets diameter, compression ratio, numberof holes, etc. New roller design. More info: https://www.youtube.com/watch?v=qSzeXOrNTnQ
Feedstock and product details
Feedstock:	Herbaceous (cereal straw, agro-residues…), woody (pine, poplar, beech, eucalyptus, pawlonia, olive tree pruning…), variety of organic wastes (including low density materials and materials with high content of fines and dust).	Product:	Pellets

CENER Biomass Department performs applied research activities in the field of biomass, providing R&D services and technical assistance to all agents of the sector. The area is focused on the development & optimization of production processes of bioproducts, solid biofuels, advanced liquid or gaseous biofuels, as well as biorefinery concepts. Indeed, the main pillars are focused on solid biofuels, bioprocesses and comprehensive sustainability assessment. The main infrastructures in this department include the Biomass Laboratory (biomass & biofuels characterization and process development at lab scale), as well as the Biorefinery and Bioenergy Centre (BIO2C).

WEIMA

Densification provider

General information
Company:	WEIMA
Country:	Germany
Contact:	info@weima.com
Webpage:	https://weima.com
Technology and process details
Technology name:	TH Series	Technology category:	Pre-processing (Physical processes and technologies), Post-processing (Physical processes and technologies)
TRL:	9	Capacity:	kg·h-1
Compression weight:	3900 t	Format of densified product:	Cyclindrical to rectangular
Size (product):	Variable length: 150x60-60x80 (LxWxH) [mm]	Other:
Feedstock and product details
Feedstock:	Wood chips	Product:	Wood briquettes

WEIMA offers, among other things, shredders, briquette presses and packaging presses. The shredders and compactors are produced in Germany. At the sites in Ilsfeld, Abstatt (Baden-Württemberg) and Annaburg (Saxony-Anhalt), the 300-strong team builds more than 1,200 customer solutions per year on more than 44,000 m² for worldwide use.

Open access pilot and demo facility providers

Currently no providers have been identified.

Patents

Currently no patents have been identified.