Briquetting of combustible waste
Economy of operation
Costs consist of
- Price of material
- Price of energy
- consumption approx. 70 kWh per 1000 kg of briquettes – briquetting press
- 120 kWh per 1000 kg of briquettes – briquetting press and dryer
- Repair costs
- Depending on the complexity of the technology and the purity of the material, we will give you an estimate
- Financial costs for technology acquisition
Revenue consists of
- Selling price of briquettes – depending on packaging and season, the price is CZK 3,000 – 5,000 per 1,000 kg of briquettes
According to our customers, it is also necessary to take into account the benefits such as time savings required for waste disposal in the workshop, improved environment, reduction of fire hazards…
Moisture content of the material
The basic condition for the production of briquettes is the moisture content of the material, up to 15% water in the material. The standard material of joinery plants meets this condition. In the case of processing material from sawmills, which is approximately 45 % moist, it is necessary to use a continuous-running sawdust drum dryer BUS, which is included in the BRISUR process line.
The briquetting presses are designed to process waste with a normal size of up to 15 mm in one direction with a minimum bulk density of 70 kg/m3.
The size of the individual particles of the raw material fundamentally influences the dosing of the material into the press chamber. The recommended size up to 15 mm means that the wood and paper should be in the shape of a thin square with a maximum side length of 15 mm. The thickness of the material should correspond to a thin shaving. Shredded straw should not exceed 30 mm. For longer lengths, there is a risk of the strips becoming entangled on the rotating parts in the hopper or of the opening of the dosing auger being covered by an impenetrable layer.
Crushing of material
The size of the input material is decisive for the quality of the briquette and the performance of the press. In general, also for other materials such as paper, straw, the smaller the fraction, the more compact the briquette.
Depending on the type and size of waste, we can supply the most suitable type of shredder from different manufacturers, selected with regard to the required performance, the size of the input material and the requirements for automation of the operation. We provide free shredding trials for certain types of waste.
Mechanical contamination of the material
Care must be taken to ensure the cleanliness of the briquetted waste. It is not advisable to sweep the waste on the workshop floor and throw it into the hopper. The briquetting press does clean up the waste, but in a segregated manner.
Watch out for nails, nuts, large bits, large thick chips, sand, stones, tools.
These items can damage your briquetting press by getting accidentally wedged in an inappropriate place, e.g. between the agitator blades and the metal bottom, dosing screw and chute, etc..
Waste contaminated with sand, soil and pebbles wears out the press tools more quickly, which then have a shortened work life. Waste contaminated with shredded tree bark, tree roots, plant bottoms are unsuitable for compaction.
Effect of chemical admixtures on briquetting
Materials contaminated with oils cannot usually be briquetted. Contamination of the material with oils and adhesives and other chemicals will sometimes prevent the material from being compacted into briquettes. We recommend that you do a material compression test for materials that you are not sure can be briquetted. We carry out the compaction test for small quantities of waste free of charge at our test centre in Malšice. Larger performance tests are carried out by agreement.
The lifetime of press tools is greatly influenced by the mineral content of the material being pressed. The higher the ash content after the briquette is burnt, the lower the tool life. The most common sources of contamination are bark, poor storage of material on unpaved surfaces, processing of plant root parts, use of poor quality grinding sheets which are easily rolled away.
Briquetting for better transport and landfill
Reduce very light, bulky and dusty materials such as polystyrene and polyurethane, tobacco and textile dust, short natural textile fibres and more by up to 50 times by briquetting. By compacting your waste, you reduce transportation costs and the cost of landfilling otherwise unusable waste.
It is advantageous to briquettize dust from extraction systems, which for hygiene reasons must be transported in special containers or in very expensive packaging. You save money on these special containers because you transport the briquettes in the normal way.
Combustion of briquettes
Wood is the oldest fuel whose combustion does not produce unwanted greenhouse gases. Depending on the moisture content, wood has a calorific value of up to 18 MJ/kg and an ash content of less than 1%. Briquettes provide greater comfort when burning, especially in gasifier boilers. This type of fuel is intended for a wide range of applications, as combustion does not require special conditions.
At present, waste paper which has no other use can also be used for combustion, provided that it is made mainly of cellulose fibres, without fillers and dyes. The calorific value of paper varies greatly according to its composition. Cardboard packaging has a calorific value of 15 MJ/kg and an ash content of 5%.
Grass and sorghum biomass and residual biomass, e.g. cereal and rapeseed straw, flax and hemp straw, are very favourable from an economic and energy point of view.
Examples of organisations that carry out combustion testing.
STROJÍRENSKÝ ZKUŠEBNÍ ÚSTAV, s. p.
Institute for Research and Utilization of Fuels, Inc.
190 11 PRAHA 9 – BĚCHOVICE