Wood Chip Production Waste for Wood Pellet or Wood Briquette Production

The production of wood chips as biomass fuel in cofiring of PLN's (Indonesia's state-owned electricity company) coal powerplants has been increasingly popular lately. Wood chip production is the easiest biomass fuel production compared to various biomass fuel products currently produced by the industry. The availability of raw materials is the main factor in the sustainability of production. The calorific value of wood chips depends on the species or type of wood used and its dryness level (water content). Hardwoods and low water content are ideal products for wood chips. And because it has a low bulk density of around 250 - 350 kg / m3, the transportation factor is another aspect that is very important for the delivery of wood chip products.

The particle size of wood chips has also been determined so that handling and storage are easier. To obtain the desired particle size of wood chips, screening is carried out after the wood trunk or pieces are chopped with a wood chipper machine. With these prerequisites, there are products that are rejected from the production process, namely wood chip products that are too large (oversize) and products that are too small (undersize). Products that are too large (oversize) can be returned to the chipper machine to be chopped again, but wood chip products with particle sizes that are too small (undersize) must be used for other things so that in addition to zero waste wood chip production, it can also provide additional income for the wood chip producer.

Small particle sizes such as sawdust from wood chip waste production can be used for the production of wood pellets or wood briquettes (pini kay briquettes). And even wood briquettes are more tolerant of slightly larger particle sizes because wood briquette products have a higher density than wood pellets, in addition wood briquettes can also be further processed into charcoal briquettes (sawdust charcoal briquettes). Wood briquettes themselves are commonly used in countries with four seasons, especially in winter for home heating. While charcoal briquettes (sawdust charcoal briquettes) are commonly used for BBQ, especially for Middle Eastern countries and Turkiye.

In the production of wood chips, it is estimated that biomass waste that is approximately the size of sawdust is around 20-25%, meaning that if wood chip production reaches 5,000 tons/month, the waste is around 1,000 - 1,250 tons/month. This is sufficient for the production of wood briquettes and sawdust charcoal briquettes. Meanwhile, if you want to produce wood pellets, especially for the export market, usually a production capacity of around 5,000 - 10,000 tons/month is needed. Of course, this cannot be done. In addition, the investment in equipment for the production of wood briquettes, sawdust charcoal briquettes and even wood pellets for this purpose is also much larger than the production of wood chips. This makes it more reasonable if the production of wood briquettes or sawdust charcoal briquettes is carried out by other parties. The other party will process the wood chip factory waste into wood briquettes, charcoal briquettes (sawdust charcoal briquettes) and because the complexity of production and equipment costs are also higher, it is natural that the profits obtained from processing this waste are also higher.

The world price of wood pellets, like palm kernel shells (PKS), has fluctuated a lot, and lately the price has tended to be low. Palm kernel shells (PKS) themselves are biomass fuels that are competitors of wood pellets in the global market but are cheaper because they come from one of the solid wastes of palm oil mills that are processed simply. With these conditions, coupled with the fact that it is very difficult to obtain adequate volumes of waste from wood chip factories, the production of wood briquettes (pini kay briquettes) or charcoal briquettes (sawdust chracoal briquettes) becomes a rational choice. In addition, the stable price of the two products makes it even more attractive to consider them.

When Choosing Wood Briquette Production Over Wood Pellet

 Wood pellets are projected to have a bright future because their needs are increasing all the time. The need for environmental programs to overcome climate change and global warming with carbon neutral fuels such as wood pellets is increasing. The use of wood pellets is mainly for power plants, both with cofiring and 100% (fulfiring) using wood pellets. 60% of the power plants in the world are coal power plants which are positive carbon fuels, thus increasing the concentration of greenhouse gases (CO2) in the atmosphere, so that CO2 emissions need to be reduced. The need for wood pellets with a large volume with an average of 10 thousand tons per export shipment and continuous means that not many can play for the production of wood pellets, because of the large raw materials needed, the large plant capacity, big investment and so on.

Screw and mechanical press type briquette

 

Hydraulic type briquette

Wood briquette is an attractive alternative for the utilization of wood wastes with a limited volume, a smaller plant capacity and so on. Wood briquette users are also different from wood pellets. Wood briquette is used mainly for heating stoves during winter in 4 seasons countries or for fueling industrial boilers. Apart from that, technology and products are also more varied than wood pellets. The briquette machine is simpler and easier to operate. The briquette machine can also handle a wider variety of raw materials, larger particle sizes, higher ash content and lower production costs. Wood Briquette technology can be grouped into 3 as follows:

Mechanical Press Briquette Machine

1. Mechanical Press

The mechanical briquette press is made like an eccentric press, and has a very simple design. The continuously rotating eccentric, connected to the piston, presses the raw material through a conical die system, where the briquettes are being formed. The large flywheel ensures extremely quiet and balanced operation. The press operates at 270 strokes per minute. The briquettes are cooled and hardened in one cooling line, which also functions as a briquette conveyor. The briquetting press is fully automatic, providing smooth operation with minimal maintenance and service. The rugged design ensures long service life and the briquetting press can operate up to 7,000 to 8,000 hours per year (583 - 667 hours per month or  20 - 22 hours per day).

The main advantage of the mechanical briquette machine is that the press can be used both for the production of briquettes for household use (consumer briquette) and also for industrial briquettes for boilers (industrial briquette). Industrial briquettes can be made as short pieces, or at random lengths or cut to a specified length. Other advantages are high capacity, low production cost, and adjustable density.

2. Hydraulic Press

In a hydraulic press, the raw material is pressed into the compression chamber at a certain rate. Inside the chamber, an appropriate amount of material is compressed or pressed with a piston. The main piston transfers the raw material into the mold forming briquettes to the required final condition and density.

The hydraulic press compression process is relatively slow. The compression cycle can be between six and 25 cycles per minute, depending on the amount loaded or the density of the briquettes. Hydraulic briquette machines are usually small in size, with capacities ranging from 50 kg / hr to 200 kg / hr. Round briquettes, with a diameter of 50 mm to 75 mm. However, at present, hydraulic briquettes can be made mainly in rectangular shapes with a capacity of up to 1.5 tons per hour. The traditional size is 150 x 60 mm, but larger briquettes can also be made.

 3. Screw Extruder Press

In the extruder press, the raw material is fed into the chamber with a screw feed. The raw material is screwed into a cone mold and an extension mold. The compression screw is conical. The screw operates at approximately 800 revolutions per minute, and during this process high heat - up to 300 degrees Celsius - is generated in a combination of friction and molding system heating. This briquette output has a hole in the middle and can be carbonized so that it becomes a product known as sawdust charcoal briquette.

 

For those who are interested in producing the wood briquette, we can help provide the machine and help with the marketing of the briquette products or please send an email to eko.sbs@gmail.com