Making Densified Biomass Fuels
There are three basic methods used to manufacture densified fuels from biomass materials. There are extrusion, mechanical compression and hydraulic compression. All the methods rely on the same basic technologies of permanently reducing the air space between the particles of the biomass, transforming loose particles into a dense, solid block.
Densified Biomass Fuel
Extrusion is the forcing of the biomass through a narrow passage (a die). This method of densification produces pellets, fuel logs and briquettes. Mechanical compression is the low pressure confinement of the biomass of the biomass into a shape, or the reduction of the volume of the biomass by means of forcing the biomass into a progressively narrower space(medium pressure), or the reduction of volume by means of a dynamic impact and extremely high pressure on small amounts of biomass. The third method is hydraulic compression which will be discussed with length in the following paragraphs.
Hydraulic compress is the confinement by means of pressure of a large amount of biomass into a small space (also called a die). Hydraulically operated briquetting machines are available in difference shapes and sizes, with varying output usually lower than 1 ton per hour. Compression pressures range from 700 to 1,750Atm. There are two categories of hydraulic machines: a) Heavy duty, industrial-type machines used to manufacture fuel briquettes for the consumer market, for the generation of space heat or power. b) Small, light duty machines mostly sued to manufacture fuel briquettes for own use in small companies that generate biomass waste.
The compression process for both these types is relatively slow, with a transient from a fast initial reduction of volume at low pressure to a longer compression phase during which the pressure reaches its peak.
Each compression cycle takes between 10 and 25 seconds, depending on the amount of materials loaded at each cycle and the required density of the finished briquette. A low amount of material, combined with a long cycle time and the highest pressure will produce the highest density, and therefore the best quality briquette. However, since the cycle time does not change a lot with the amount of materials loaded at each cycle, the manufacture of a high quality briquette penalises the output capacity of the system.
With technology innovation, the GC-HBP125 hydraulic briquetting presse gains new features on a higher stage. The advantages of the hydraulic briquette presses are low noise, easy operation, small space occupation, relatively light weight, and impeccable overload protection system, long service lifetime of molding part at about 1500-2000h, etc. Furthermore, the pressure display panel is installed to the hydraulic briquette machine, which can exactly show the working status of the machine, very convenient for the operator to observe and operate the machine.
Well, then comes the electrical control system. The electrical control system is made of Siemens PLC system and Schneider Electric components. The control of the machine can be realized by operating on the touch screen, where the key parameters are set and operation orders are released according to the programs. Meantime, the touch screen can conduct synchronous simulation operation that can display the current working conditions.
So it means the production of the high quality briquettes with the hydraulic briquette press will be easy, efficient and cost effective. And the key parameters of the hydraulic briquette press are shown below for your reference.
|Diameter of Briquette(mm)
|Volume of Hopper(m3)
For more information:  was written by Girodanno Checchi, CEO OF sunomi, exclusive distributor of Di Piu briquetting systems in North America from Bioenergy briquettes.