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 category	Technology name	TRL	Capacity [kg/h]	Compression weight [t]	Format of densified product	Feedstock: Food waste	Feedstock: Garden & park waste
Company 1	[Country HQ location]	[Technology category (if different sub-categories are defined this has to be specified here, the available categories can be found on each technology page under the chapter Process and technologies)]	[Technology name (the "branded name" or the usual naming from company side)]	[4-9]	[numeric value]			●	●
Company 2	[Country HQ location]	[(if different sub-categories are defined this has to be specified here, the available categories can be found on each technology page under the chapter Process and technologies)]	[Technology name (the "branded name" or the usual naming from company side)]	[4-9]	[numeric value]			●	●

Company 1

Densification provider

General information
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Technology and process details
Technology name:		Technology category:	Pre-processing (Physical processes and technologies), Post-processing (Physical processes and technologies)
TRL:		Capacity:	kg·h-1
Compression weight:	t	Format of densified product:
Size (product):	(LxWxH) [mm]	Other:
Feedstock and product details
Feedstock:		Product:

Open access pilot and demo facility providers

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Patents

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