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.

Consumer Briquette and Industrial Briquette

The use of biomass briquettes from both wood wastes and agricultural wastes is not yet popular in Indonesia, its use is still very limited. And the briquettes used are actually intermediate products in the sawdust charcoal briquette industry. Sawdust briquette or wood briquette is a briquette product that comes out of the screw extruder and can actually be further processed into sawdust charcoal briquette through the carbonization process. The sawdust charcoal briquette product itself is mainly used for barbeque or roasting meat, especially in Middle Eastern countries, Turkey and Saudi Arabia. Domestic use of sawdust charcoal briquette is also still very limited. Judging from the type of briquette, the actual product produced is the type of consumer briquette or briquette which is sold by retail for household use.

Industrial briquette production is hardly found in Indonesia today. Industrial briquette is a briquette that is used for fuels in industries such as fuel for boilers or even power plants. Even though in terms of the production process, briquette is easier and cheaper than pelletizing, such as wood pellet production. In addition, investment in equipment for briquette is also cheaper than pelleting. A number of biomass materials which are generally difficult to pellet are usually easy with briquette. The preparation of raw materials for briquette is also easier than for pellets because of the more loose tolerances for particle size and dryness (moisture content).

In contrast to pelleting, apart from only one type of technology for compaction (densification), namely the roller press, briquette has 3 types of technology, namely the mechanical press, piston press and screw press. In addition, the shape, size and density of the briquette produced are also more varied. Industrial briquettes are made with mechanical press technology, while consumer briquettes can be made by mechanical press, piston press or screw press. The puck is an example of the best shape for industrial briquettes. Empty fruit bunch or EFB of palm oil as well as mesocarp fiber are very potential for industrial briquette production, for more details can be read here.

Puck shape industrial briquette

Consumer Briquette

In addition, wood dust waste from the MDF (Medium Density Fibreboard) industry can also be used for the production of the industrial briquette. While the consumer briquette made with a mechanical press is in the form of a long cylinder, or if it is with a screw press the shape is octagonal or hexagonal, while the piston press is usually in the form of a block. Consumer briquette is mainly used for heating in winter. In subtropical countries when winter arrives, things that can be done are mainly room conditioning so that people in the area continue to be active, namely by heating the room where they live.