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.[1] 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
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.[1]
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.[1]
Product
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.[1] 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
| 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)
| General information | |||
| Company: | CENER BIO2C | 
| |
| Country: | Spain | ||
| Contact: | Goizeder Barberena, [email protected] | ||
| 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
| General information | |||
| Company: | WEIMA | 
| |
| Country: | Germany | ||
| Contact: | [email protected] | ||
| 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.
References
- ↑ a b c d Christian Riuji Lohri, Stefan Diener, Imanol Zabaleta, Adeline Mertenat, Christian Zurbrügg, 2017-03: Treatment technologies for urban solid biowaste to create value products: a review with focus on low- and middle-income settings. Reviews in Environmental Science and Bio/Technology, Vol. 16, (1), 81–130. doi: https://doi.org/10.1007/s11157-017-9422-5