Biomass energy has numerous application settings, such as biogas, alcohol, as well as biomass molding gas. Biomass molding fuel is the most hassle-free as well as affordable mode. Biomass molding fuel has biomass pellets as well as biomass briquettes 2 forms. Biomass pellets gradually replace briquettes owing to small size, high density, as well as very easy use.
Biomass briquettes and biomass pellets
Biomass pellets are made of wood pellet maker. It makes use of high pressure from roller as well as die to mold and mildew biomass materials right into high-density strong pellets. The molding effect is affected by the basic material high quality, molding procedure, and equipment efficiency. To improve the molding effects of biomass pellets, you should discover the following factors.
The raw products for making wood pellets are made up of different contents. They have different reactions in high heat and high pressure. Some materials like healthy proteins as well as lignin will certainly soften and have gluing impact. Some contents like cellulose and also not natural particles are difficult to break down or split. They impede the molding of wood pellets, but they occupies the most part of biomass materials
The make-up of raw materials has the largest impact on the pellet durability. The complying with chart shows the Pellet Quality Coefficient (PQF) of numerous typical resources
The larger the PQF, the tighter the timber pellets are bound. Some products like bentonite, lignin have high PQF. They can act as binders. Some materials like acid oil has low PQF, the bits inside can’t bind together efficiently. Loose biomass pellets has much less toughness. Only when the total PQF of all products amount to greater than 4.7, the timber pellets can materialize efficiently.
The excellence of basic materials
Basic material with smaller granularity have bigger surface, so they are very easy to bind. As well as the generated pellets are much more compact and also smooth, challenging to damage. The smaller the granulates, the higher the timber pellet stamina. However also tiny granulates needs high power intake for grating. It is not recommend to go after also tiny granulates.
The granulates should be consistent in size. Too huge granulates are challenging to bind with others, and also the surface area have a tendency to be rough. Huge fragments normally cause glowing split, where the timber pellets are easy to damage. As well big granulates are hard to get involved in the die holes. They will intensify the abrasion of pellet mill die as well as roller, decrease the wood pellet manufacturing, as well as reduced the molding rate.
Therefore, the granularity of resources should be 1/2 -2/ 3 of the wood pellet dimension. You can adopt a screener with the pore diameter less than 10mm in shattering process, to make sure that the raw materials can meet the criterion for pelletizing as well as mixing, and also reduce the power usage and also devices abrasion.
The moisture of resources.
The dampness in the biomass products have lubrication function. They can reduce the friction between the granulates, and improve their bonding. The dampness can also soften the materials to make sure that they are much easier to deform and also mold.
Biomass products differs in wetness material, normally in between 8% -15%. The dampness is affected by temperature level For those materials with over-high wetness, we require to dry them prior to making pellets.
The molding temperature.
The biomass molding is to make the organic parts of biomass soften, bond and transformed under high temperature as well as pressure.
Generally, the organic matters soften at the temperature level of 70 ℃ ～ 80 ℃, bond at the temperature level of 160 ℃, liquefy at the temperature level of 240 ℃. With the rise temperature level, the raw products come to be much more soften, the liquidity increases, the resistance in between basic materials decrease, so they are much easier to mold and mildew. As measured, the molding pressure in heat is fifty percent of that in heat.
Heat is not constantly excellent. Over-high temperature level will certainly cause carbonization of the biomass materials. Such carbonization is neither consistent nor manageable, which will certainly prevent molding as well as impact the timber pellet high quality.
The density of material layer
In pellet machines, there is a clearance in between the roller and die, where the biomass materials form a layer. The clearance can be changed from 0.1 mm to 0.3 mm. To produce small-size wood pellets, the clearance is tiny, and the other way around.
The density of material layer additionally affect the power usage of the pellet equipment. When the material layer is thick, the extrusion stress will raise. With too much basic materials entering into the die holes, they will certainly be as well limited to discharge, as well as also trigger damage to the equipment. When the product layer is also slim, the extrusion pressure is small, the raw products pressed right into the die holes are insufficient, so the wood pellet manufacturing is reduced.
The picture below shows the impact of basic materials on the extrusion pressure. B describes suitable density, A refers to the layer is too thick, C refers to the layer is as well slim. In the A status, the extrusion pressure enhance a great deal owing to the long pressing area. In the C condition, the extrusion force is as well little. So an appropriate thickness is a facility of high-efficient production.
Extrusion speed identifies the time that raw materials remain in the die openings, so as to influence the molding high quality. When the raw products leave in the die holes for short time, the system power usage is low, but the timber pellets might hang. When the raw materials leave in the die openings for long, the timber pellets will have greater thickness and also quality, the system power consumption likewise boost.
If the raw materials leave in the die openings for also long, the rubbing will certainly be expensive, the pellets will be also thick, the pellet device will be warm and also even quit.
The extrusion speed of a pellet machine is affected by the roller size as well as revolving rate. A correct extrusion rate make certain the devices job continually with low power consumption.
The squeezing pressure on the raw products identifies the thickness of timber pellets. High pressure extrusion and also friction will soften and warp the raw materials as well as bind them with each other.
If the extrusion toughness wants, the raw products can not be molded effectively. If the extrusion strength is too expensive, it will exacerbate the abrasion of dies and also add to set you back.
The parameters of die opening
The parameters of die openings are limited by resources granularity, extrusion rate, extruding stamina. Oppositely, the criteria of die openings affect the molding of timber pellets.
Pellet mill die openings have certain compression ratio. High compression proportion enhance the extrusion toughness, lower the extrusion speed. They are suitable for the products with reduced glue force.
The hole entrance shape affect the rate of resources getting involved in the die holes, as well as influence the density of raw materials.
The parameter of die openings should be adjusted according to different materials, so that you can obtain top notch wood pellets with low unit power intake.