EFB Charcoal Briquette for Substitution of Sawdust Charcoal Briquette

Continuity of raw material supply is the main thing for the sustainability of a production, as well as the sawdust charcoal briquette industry. The lack or even stop of supply the sawdust or wood waste as raw material for sawdust charcoal briquette makes production disrupted and even stops. And such conditions have now been experienced by some the sawdust charcoal briquette factories. In fact, from the market side the demand for sawdust charcoal briquette is very large, especially in Turkey, Saudi Arabia and the Middle East. Continuous alternatives to raw materials and availability in large quantities are the choices. An empty fruit bunch (EFB) can be an option. Why? EFB is a solid waste of oil palm mills which are large in number and are generally not utilized. Palm oil mills with a capacity of 60 tons / hour FFB produce EFB waste of 13.2 tons / hour or 264 tons / day. And currently there are approximately 1,000 oil mills throughout Indonesia.

The next question is, can the quality of charcoal briquette made from EFB compete with sawdust or wood waste? Judging from its use for fuel or energy, the quality of EFB is lower than sawdust or woody waste belonging to woody biomass while EFB is a biomass of agricultural waste (agro waste). The measure of quality can be shown mainly from the calorific value and ash content. The calorific value of the EFB charcoal briquette is lower and the ash content is greater than the sawdust charcoal briquette. Based on these conditions, the price of sawdust charcoal briquette should be slightly lower than sawdust charcoal briquette. But in an effort to overcome the problem of waste and be able to increase income, the profits from the production of the EFB charcoal briquette should still be very attractive.

The implementation of EFB charcoal production can work with palm oil mills, namely as a provider of raw materials as well as electricity providers for their operations. A number of palm oil mills with excess biomass waste such as palm kernel shells and mesocarp fiber can be used for electricity production. If it is still lacking, waste in the plantation such as fronds and leaves can also be used to fuel the power plant. The location of many palm oil mills is in the remote areas and there is no other electricity source that is sufficient so that's make the palm oil mill automatic as a power plant also which is generally used internally but can also be upgraded for external use. As for management and business, it is possible to produce EFB charcoal briquette that are integrated palm oil mill or separatd and managed by ownself. Of course the choice is very dependent on the management pattern of the company, especially in its business development division.

Focus on Biomass Ash

Utilization of biomass with thermal route which is combustion and gasification will be generated ash residue. While the pyrolysis due to work at low temperatures (400-600 C) and without oxygen / air then there is no ash. Minerals contained in the biomass will remain behind in the form of charcoal products in the pyrolysis process. Ash content and ash chemistry greatly affects the utilization of biomass in addition to heating value, particle size and moisture content. In general characterization of ash from biomass is described by Bryers as follows:

1.     High  silica (Si) and potassium (K) ash content  while the calcium (Ca) is low, with low fusion temperature derived from the group of agricultural biomass wastes.

2.     Low silica (Si) and potassium (K) ash content while calcium (Ca) is high, with a high fusion temperature derived from a group of nearly all the woody biomass. Specifications are best for combustion and gasification.

3.     High potassium (K) and phosphorus ash content, with low fusion temperature derived from faecal matter such as poultry and cattle dung.

Biomass Ash Content

The ash content of various types of biomass indicate slagging behavior.  In general, the higher ash content, the greater the tendency of its slagging behavior. But this does not mean that low ash slagging not show the phenomenon.  Operating temperature, ash chemistry and ash content are variables the occurrence of slagging. If conditions favor the slagging will be even greater. Minerals such as SiO2, Na2O and K2O more tendency toward the occurrence of slagging. Usually slagging occurs in biomass with ash content of more than 4% and non-slagging fuel with ash content less than 4%. According to the composition of the melt, fuel-biomass fuels are grouped into severe or moderate slagging.

Biomass Ash Chemistry 

Issues arising from these ashes is clogging the air intake holes or slagging that will reduce the thermal efficiency of the gasification and combustion process related air supply and biomass distribution in the process unit.

Ash Slagging

So before processing the biomass waste, consider and note the ash content and its chemistry so that it can deliver optimum results.