Production of EFB Pellet EFB or EFB Biochar ?

One of the main obstacles for palm oil mills to develop their business is the availability of electricity. With locations that are generally located in remote areas in the middle of palm oil plantations, palm oil mills do not get electricity supply from PLN (Indonesia State Owned Electricity Company). Eventhough electricity is very important in a production process, such as in the production of EFB pellets. Even though empty bunches or EFB in general are an environmental problem for palm oil mills. If every ton / hour of EFB pellet production takes 300 KW, then for production of 10 tonnes / hour (5,000 tonnes / month) 3 MW of electricity is needed, export of biomass fuels such as wood pellets and PKS (palm kernel shell)  with bulk shipments usually requires 10 thousand tons / shipment. So if the production of EFB pellets is planned for 10 thousand tons / month so that every month can export the EFB pellets, the factory capacity or EFB pellet production is 20 tons / hour (10,000 tons / month) 6 MW of electricity is needed. For palm oil mills, utilizing liquid waste or POME to become biogas is a potential source of energy for the production of electricity. However, with a palm oil mill capacity of 30 tonnes of FFB / hour, only about 1 MW of electricity is generated from POME biogas, so to produce 6 MW of palm oil mills with a capacity of 6 x 30 tonnes of FFB / hour are generated equal to 180 tonnes of FFB / hour. In fact, the average palm oil mill has a capacity of 45 - 60 tonnes of FFB / hour, so it is impossible to generate 6 MW of electricity from the palm oil mill's POME biogas.

The use of EFB pellets is the same as wood pellets and PKS is mainly for power generation. All three are biomass fuels. The high chlorine and potassium content in empty palm fruit bunches or EFB makes their use limited to power plants due to corrosion and scale causes. Not all power plants can use EFB pellets at large capacities or quantities. The use of coal-fired power plants with pulverized combustion technology can only be used with a small ratio or an estimate of less than 5%, but can be used more or even 100% in fluidized bed and stoker types of power plants. The capacity of fluidized bed and stoker type PLTU is generally much smaller than pulverized combustion.

When the biomass source is managed properly, the use of biomass fuel is an environmentally friendly and sustainable fuel. Biomass fuels like this are carbon neutral fuels, because they do not increase the concentration of CO2 in the atmosphere. This is because the biomass as a fuel source comes from plants whose growth is from the photosynthesis process, one of which uses CO2 from the atmosphere, so that when the biomass is burned, there is practically no addition of CO2 to the atmosphere. In general, there are 2 ways to overcome the CO2 concentration in the atmosphere which causes climate change and global warming, namely the carbon neutral scenario and the carbon negative scenario. In a carbon negative scenario, CO2 in the atmosphere will be captured and absorbed so that it is no longer released and the concentration of CO2 in the atmosphere can be reduced, as in the biochar application below.

Whereas in the production of biochar with pyrolysis, besides not requiring a large amount of electrical power for its operation, electricity can also be generated from the use of excess energy from pyrolysis itself. By using the excess energy from pyrolysis, the palm oil mill boiler fuel does not need to use palm kernel shells and fiber. The use of gas or liquid fuels from the excess energy of the pyrolysis process also makes burning emissions cleaner. To achieve more complete combustion, gaseous or liquid fuels are better than solid fuels. Palm kernel shells so that everything can be sold or even exported. The biochar product applied to palm oil plantations will also improve the quality of the soil so that fertilizer use can be reduced and the productivity of palm oil fruit will increase. Biochar also absorbs CO2 from the atmosphere so that the use of biochar in large palm oil plantations means that with massive applications it can also be used for carbon trading. Recent developments indicate that the use of biochar is increasingly widespread, such as biomaterials for construction, transportation, plastics, packaging, furniture and so on. The use of biomaterials for these products means substituting the use of fossil-derived raw materials.

So based on the above review, the production of biochar with pyrolysis is more profitable and easy to implement for palm oil mills compared to EFB pellet production. The addition of electricity production with a large capacity and the availability of sufficient raw materials is not easy and cheap for the average palm oil mill in Indonesia with a capacity of 45 - 60 tons of FFB / hour. Whereas in the production of biochar with pyrolysis, a certain amount of energy is produced which can be used for various purposes and the use of biochar is also multi-beneficial. Palm oil mills should consider this in particular in the aspects of waste management, plantation productivity, environmental aspects and business development, for more read here. Based on experience, the cost structure of the CPO or palm oil production business consists of about 80% of the cost of production is the cost of crops or plantation aspects, while the other 20% is the cost of processing or mill aspects. And the highest cost aspect of palm oil plantations is the cost of fertilization so that if the need for fertilizer can be reduced and the productivity of palm oil can be increased, of course it is very profitable, biochar is effective and efficient to use for this.

Utilization of Excess Energy from Biochar Production with Pyrolysis

Most of the production equipments for biochar are currently obsolete, so that the productivity and quality of the products produced are low, also causing environmental problems, namely air pollution. In equipment with this technology, the production process is also not running efficiently, indicated by the large amount of energy or heat loss so that it is less profitable. Slow pyrolysis technology is the best technology for biochar production because it maximizes the production of a solid fraction (biochar). Meanwhile, other thermal technology group are not so suitable for biochar production, for example fast pyrolysis, the main objective of which is to maximize its liquid product or biooil, gasification is the main objective of maximizing gas or syngas product as well as hydrothermal carbonization (HTC) or wet pyrolysis requiring high pressure operating conditions so that it is difficult to be applied. Modern slow pyrolysis technology will operate autothermal / self sustain fuel, safe, good process control and energy management, so that in this way in addition to energy being used for the pyrolysis process itself, excess energy can also be used for other needs such as electricity or heat production.

There are three main variables for this pyrolysis process, namely heating rate, duration / residence time and temperature. The quality and quantity of biochar are determined by these process variables. For example, biochar production with a temperature of less than 400 C will produce acidic biochar, while biochar production above this temperature will produce alkaline biochar. Currently, the pH of biochar produced ranges from 4 to 12. There are also those who make a category about the pyrolysis temperature for biochar production, namely, low with less than 250 C, medium (250 - 500 C), high with more than 500 C. According to some researches fixed carbon also increased from 56% to 93% at 300 and 800 C pyrolysis temperatures. The surface area also increased from 120 m2 / gram at 400 C to 460 m2 / gram at 900 C. 

And indeed, basically the quality and quantity of biochar is determined by the raw materials used and the conditions of the production process, especially the pyrolysis. In fact, to ensure the quality of biochar, all aspects need to be considered such as raw materials and production processes such as the pyrolysis operating temperature should not be more than 20%, interruptions when production are allowed as long as the conditions of subsequent production parameters are maintained the same as before the restart. The composition of the raw material should not fluctuate more than 15%. And for modern pyrolysis equipment, the excess energy must be utilized with an estimated 35-60% of the energy from the biomass raw material found in pyrolysis gas. A number of agricultural waste processings can use the pyrolysis optimally, including:

1. Palm Oil Industry
The use of pyrolysis technology for palm oil companies, especially in Indonesia, is currently ideal. This is because palm oil mills or CPO mills produce a lot of solid waste biomass namely, empty fruit bunches/EFB, fiber and palm kernel shell. And because palm kernel shell / PKS has a lot of demand both from within and outside the country for industrial fuel and power plants, this PKS should not be used as raw material for pyrolysis or biochar production, but can be directly used as a trading commodity.  The EFB and fiber are used as raw material for biochar and then the biochar is used to improve the soil quality of palm oil plantation so that fresh fruit bunch or FFB productivity increases. Excess energy from pyrolysis is then used as boiler fuel so that it can reduce or even replace all PKS as the the boiler fuel. And because the boiler fuel is replaced with the excess energy pyrolysis, so can be  all of the PKS can be sold. 

2. Integrated Coconut Industry

Products from coconut processing such as copra, dessicated coconut, and nata de coco require heat in the production process. Coconut shell charcoal is also a favorite charcoal with a large market demand. The charcoal will usually be further processed into briquettes for energy and activated carbon for various industries. For biochar production, coconut industrial wastes such as coir/fiber, bunch and midrib can be used. Excess energy of pyrolysis can be used for the production of the above products and other advanced products. The low productivity of Indonesian coconut production needs to be improved, one of which is by improving soil quality with biochar. In addition, there are so many coconut plantations in Indonesia that need to be replanted so that improving soil quality to achieve the desired production is increasingly important. 

3. Corn Plantation

Efforts to increase food products need to be taken seriously, this can be done in two ways, first by expanding the land or making new rice paddy fields for production and the second by improving the quality of existing land so that productivity will increase. Biochar is very effective and efficient for the second method above. Besides being used as a human food source, corn is also used for animal feed. With the projection of the human population continuing to increase, the need for food either directly by consuming corn or indirectly from livestock such as meat and eggs. Poultry or chicken feed production ranks first of other animal feed production, or in the world almost half of the animal feed produced is chicken feed. Corn cobs and husks are agricultural waste that can be used for biochar production. Excess energy from the pyrolysis process can be used for drying corn and other advanced processes.

4. Rice Paddy Farming 

Rice or paddy is the staple food of most of the Indonesian population. The area of irrigated rice fields is decreasing throughout the year. This encourages the use of non-irrigated rice fields or dry land for the production of this rice. Biochar is able to improve the quality of dry land soils, such as in corn farming. Rice husks are rice paddy agricultural waste that can be used for biochar production. Excess energy from rice husk pyrolysis can be used for drying the rice paddy itself so that it becomes dry grain ready to be milled, or for other purposes. With the improvement of soil quality, rice productivity can be increased and it is not impossible that food self-sufficiency, especially rice, can be achieved, as has been achieved by Indonesia some time ago.