Palm Oil Mill: Just Replacing Boiler? Or Are You Also Looking for a Solution to Address the Problem of Empty Fruit Bunches and Generate Additional Profits?

As palm oil plantations in Indonesia continue to expand—currently covering approximately 17 million hectares—the demand for palm oil mills is also increasing. About 10 years ago, there were approximately 1,000 palm oil mills in Indonesia, but according to the latest data from the Ministry of Agriculture of the Republic of Indonesia, the number of active palm oil mills (POM) in the country is now estimated to be between 1,200 and 1,500. These palm oil mills are primarily located on Indonesia’s two largest islands: Sumatra (52.69%) and Kalimantan (42.71%), while the remainder are in Sulawesi, Papua, and several other islands, where their presence is relatively small (each accounting for less than 3%). In terms of ownership, the majority of palm oil mills in Indonesia are owned by large private companies (93%), with the remainder owned by state-owned enterprises (7%). A single large private company may own a dozen or even dozens of these palm oil mills. 

One of the main equipments for palm oil mill operations is the boiler. In fact, given the current palm oil mill production process, boilers are mandatory for palm oil mills; more details on the reasons can be found here. Boilers can also be considered the "heart" of a palm oil mill, converting water into high-pressure steam to run the production process and generate electricity for the mill and its employee housing. Like all production equipment, boilers have a lifespan. When a boiler's lifespan is exceeded, it becomes not only uneconomical due to high maintenance and operational costs, but also dangerous.

The average lifespan, which is the technical and economic life of a palm oil mill boiler, is 20 years. Once this lifespan is exceeded, investing in a new boiler becomes more profitable. The majority of palm oil mills in Indonesia use water tube boilers (e.g., Takuma or Vickers). This type of boiler circulates water through hundreds of externally heated pipes fueled by palm oil waste in the form of shells and fibers. Because these pipes interact directly with extreme heat and water scale, these internal components wear out most rapidly. The three main factors affecting the boiler's lifespan are boiler feedwater quality, fuel characteristics, and regular maintenance.

When the time comes to replace the boiler, and considering the mountains of unused empty fruit bunches (EFB), palm oil mills might consider using them as boiler fuel. But given their large size and high moisture content (>60%), how can they do that? This is certainly a reasonable and innovative idea, given the urgency of replacing the boiler and simultaneously facing the problem of biomass waste. Technically, as biomass waste, it can certainly be used, but is it economically feasible to treat or prepare the empty fruit bunches (EfB) until they are ready for use as fuel? This is the challenge.

Proven evidence will dispel any doubts or theoretical narratives. Likewise, a unit that can process empty fruit bunches (EFBs) and also serve as an additional energy source for boiler operations (cogeneration) at the palm oil mill. With this equipment, not only can the problem of empty fruit bunch (EFB) biomass waste be resolved, but the palm kernel shells (PKS), which have been used as boiler fuel along with the fiber, can be 100% sold directly, providing a source of income. Furthermore, the potassium-rich ash content of empty fruit bunches (up to 30%) also has the potential to be used as fertilizer, including for use on the palm oil plantation. For more details, please read here. Visiting and observing the unit in action can also serve as a means of proving the point, thereby increasing the confidence of palm oil mills interested in this solution.

Beyond technical factors, economic considerations will undoubtedly be a crucial consideration in implementing this equipment. By considering several factors, particularly those currently operating in the palm oil industry, a comprehensive and accurate economic analysis can be conducted to reach a decision on use of the equipment. In an era of renewable fuels, efficiency, zero waste, and increased profitability, this equipment, which serves as a supplemental energy source (cogeneration) for the palm oil mill's boiler, is worth considering for palm oil mills currently facing boiler replacement. 

Maximizing Palm Oil Mill Profits with Cogeneration Utilization of EFB (Empty Fruit Bunch) and Export of PKS (Palm Kernel Shells)

As a profit-oriented company, maximizing profits is a natural and ongoing endeavor. Besides increasing efficiency, innovation can also be pursued, creating or developing new businesses. This is especially true if the innovations involved in creating new businesses also address environmental issues, such as utilizing palm oil mill biomass waste. In palm oil mills, empty fruit bunch (EFB) waste is generally underutilized, or if utilized, it is still suboptimal or inadequate, such as composting empty fruit bunches (EFB).

Empty fruit bunches (EFB) are a significant biomass waste product from palm oil mills, accounting for approximately 22% of the total production, but are generally underutilized and pollute the environment. Utilizing EFB through cogeneration will not only address the problem of EFB, but also generate heat or energy to replace the use of palm kernel shells (PKS) as boiler fuel, and also produce high-quality organic potassium ash fertilizer.

If the PKS used for boiler fuel reaches 50%, then using this technology means that 50% of the PKS can be recovered, or 100% of the PKS can be sold or exported. For example, a palm oil mill normally sells 3,000 tons of PKS per month. With this technology, the mill can sell 6,000 tons of PKS per month. This would certainly increase the supply of PKS significantly.

Even if applied on a larger/macro scale, namely in Indonesia with CPO production of around 50 million tons/year, the actual production of PKS is around 12.5 million tons/year. However, with the current practice of utilizing PKS as boiler fuel, say reaching 50% of PKS production, the actual amount of PKS that can be sold/exported by palm oil mills is 6.25 million tons/year. Now, with the use of this technology or the installation of equipment (EFB furnace cogeneration), the amount of PKS that can be sold/exported will be close to or equal to the PKS production in the mass balance or diagram above (not subtracting the amount burned in the palm oil mill boiler).

The demand for palm kernel shells (PKS) is increasing in line with the global decarbonization trend. In fact, PKS is a major competitor for wood pellets in the global biomass fuel market. Large PKS users come from Japan and Europe. PKS exports to Japan typically reach around 10,000 tons per shipment, while those to Europe typically reach a minimum of 30,000 tons per shipment due to the longer distances and the use of handymax or even panamax vessels. Cogeneration of empty fruit bunch (EFB) furnaces with palm oil mill boilers will increase the volume of PKS that can be sold or exported. Implementing this technological innovation, besides being the fastest and most practical, also offers multiple benefits, making it worthy of consideration. It could even become a trend and even a standard operating procedure in Indonesia's approximately 1,000 palm oil mills.

Why is There No Biochar Production for The Palm Oil Industry Yet?

Even though biomass waste is abundant in the palm oil industry, both in the plantation area and in the palm oil mill area, most of the biomass waste, especially empty fruit bunches or EFB, is still not utilized or is simply piled up or thrown away. In fact, if the palm oil industry has a strong vision about maximizing profits by minimizing the occurrence of waste, especially biomass, and maximizing environmental sustainability as well as being part of the climate solution, then biomass waste, especially empty fruit bunches or EFB, is a big opportunity.  Currently, special department in the palm oil industry that specifically deal with sustainability issues are starting to be created by palm oil companies. Waste management issues including the utilization of EFB, reducing soil and water pollution due to fertilizers and increasing fertilizer efficiency are the concerns of the sustainability department.

The empty fruit bunches or EFB can be used as fuel so that most or all of the palm kernel shells or PKS can be sold directly and even exported. Palm oil mill boiler fuel currently uses fuel in the form of palm fiber (mesocarp fiber) and some palm kernel shells / PKS, which can be replaced using empty fruit bunches (EFB) and palm fiber (mesocarp fiber) and without palm kernel shells / PKS. Palm kernel shells / PKS are a very popular biomass fuel in the global market that competes fiercely with wood pellets. By being able to sell all palm kernel shells / PKS and at the same time utilize empty fruit bunch / EFB waste, the palm oil industry will provide many economic benefits.

The use of empty fruit bunches / EFB and mesocarp fiber as a heat source for the boiler is not burned as usual or as is done by all palm oil mills today but must be gasified or pyrolyzed so that another product is produced in the form of biochar. Although gasification can be used to produce biochar, pyrolysis is more recommended because the quality and quantity of biochar will be better. The biochar can later be used for the palm oil plantation itself. The use of biochar in palm oil plantations will significantly save on fertilizer use as well as reducing water and soil pollution due to inefficient use of fertilizer. The biggest cost in operating a palm oil plantation is fertilizer, so by using biochar these operational costs can automatically be reduced. Biochar will become a slow release agent so that fertilizer use will be more efficient or increase NUE (Nutrients Use Efficiency).

Empty fruit bunches / EFB and mesocarp fiber are solid waste from palm oil mills so the waste is located around the palm oil mill, while biochar is used for palm oil plantations. In palm oil companies, management is generally separated between the plantation and mill departments. The use of biochar in palm oil plantations while the raw material comes from palm oil mills requires special arrangements regarding this matter. This could be, for example, trucks transporting fresh fruit bunch / FFB from the plantation to the palm oil mill, then after the FFB is unloaded at the mill, they then go to the plantation again carrying biochar from the palm oil mill.

Currently, no one is utilizing empty fruit bunches / EFB and palm mesocarp fiber as a source of boiler heat and biochar production. The main factor causing this is the main orientation or vision of the palm oil company itself as described above. This is predicted to change soon as awareness of climate issues increases and reaches all levels, especially in sectors related to energy and sustainibility. Moreover, when biochar is applied to plantation land, it also gets carbon credit as carbon sequestration. The smoke coming out of the boiler furnace will also be cleaner as seen from its opacity. The use of gas and liquid fuels from pyrolysis by-products will produce better combustion quality as well as smoke from the chimney. And even the liquid products from pyrolysis can also be used as biopesticides and organic fertilizers. Boiler efficiency will also increase because it uses boiler feed water (BFW) in the form of hot water from the condenser output of the pyrolysis unit.

Apart from old palm oil mills which really want to upgrade their industrial energy systems and fertilizer efficiency in their plantations including sustaibility according to this vision, new palm oil mills whose status is in the development stage should be able to apply this concept more easily. New palm oil mills can immediately follow developments and demands of the times so that they become trend setters with this vision. Being a pioneer and trend setter is indeed more difficult and even risky than just being a follower, but this will raise the reputation and become a leader in the industry so it should also have a positive impact on the company's business performance. A worthy effort.

Upgrading the Palm Oil Industry in Indonesia

With Indonesia's palm oil plantation area reaching around 15 million hectares and palm oil mills reaching 1000 units, efforts to upgrade the palm oil industry are important and strategic. Indonesia's palm oil or CPO production per year is around 46 million tons (while Malaysia is in second place at around 19 million tons/year). Efforts to upgrade the palm oil industry will increase productivity/efficiency, sustainability and encourage the creation of new products/markets as well as added value for palm oil. Things that can be upgraded include a number of key areas including bioenergy, biomaterials and oleochemicals, food and feed, soil fertility (land, soil and cultivation), post-harvest and processing, waste processing and the environment as well as socio-economics, management and business.

One concrete thing that can be done is the production of biochar from palm oil mill waste, especially empty fruit bunches (EFB) and palm fiber (mesocarp fiber). Biochar production by pyrolysis will produce excess energy (syngas & biooil) which can be used as boiler fuel in palm oil mills. Furthermore, the application of biochar with fertilizer on palm oil plantations will become slow release fertilizer (SRF), thereby increasing nutrient use efficiency (NUE). The condition of many oil palm plantations on acidic soil will also increase in pH when biochar is applied.

In palm oil plantation operations, fertilizer is the highest cost component so that if you can increase fertilizer efficiency it will provide significant benefits. The use of biochar is the solution, namely SRF. SRF also minimizes environmental pollution due to the use of fertilizer. Meanwhile, in palm oil mill operations, energy is a vital component, and if this can maximize the use of waste that has no economic value, it will certainly be very economical apart from of course overcoming environmental problems caused by this waste. Currently, palm oil mills use palm fiber (mesocarp fiber) and some palm kernel shells (PKS/palm kernel shell) for boiler materials, while generally the empty fruit bunches (EFB) have not been used, even though these palm kernel shells (PKS) can be sold directly and sell well. This means that if the energy source only comes from palm fiber (mesocarp fiber) and empty fruit bunches (EFB), 100% of the palm kernel shells (PKS) can be sold. This can be done by pyrolysis.

Biochar in the soil can last hundreds or even thousands of years. Biochar which comes from agricultural waste such as empty fruit bunches (EFB) and palm fiber (mesocarp fiber) will become a carbon sink through carbon sequestration, so that the concentration of CO2 in the atmosphere is reduced as long as the biochar is not decomposed. From a climate perspective, this is very beneficial and later you can get compensation in the form of carbon credits. A number of standards and verification methods to facilitate monetization are currently being developed.

Empty fruit bunches (EFB) and palm fiber (mesocarp fiber) are waste from palm oil mills, whereas biochar is applied in palm oil plantations. Management in the palm oil industry generally separates the mill division and the plantation division, so new management methods are needed if biochar production using pyrolysis is carried out. Apart from using biochar for core plantations (managed by palm oil company), it can also be used for plasma plantations (managed by farmer).

Biochar as a Solution to Deforestation in Indonesian Palm Oil Plantations

Palm oil trees are not native to Indonesia but come from West Africa and were brought by the Dutch colonialists in the mid 19th century. At first they brought 4 grains and planted them in the Bogor Botanical Garden which is now a palm oil monument. The first palm oil plantation were established in Indonesia in the early 1900's in North Sumatra. The development of the palm oil industry and its subsequent plantations is very rapid, especially in the last 10 years and it is currently estimated that the area of Indonesian palm oil plantations reaches 15 million hectares. As the largest vegetable oil-producing plant in the world and the area of palm oil plantations is also the largest in the world, of course, palm oil has a strategic value in the Indonesian economy. The average rate of growth for Indonesian palm oil plantations is 6.5% per year or the equivalent of about 500 thousands up to 1 million hectares per year for the last 5 years, while the increase in palm oil fruit production or FFB (fresh fruit bunches) is only 11% in average. In fact, the largest increase occurred in 2017 which increased by 2.8 million hectares. From 2015 to 2019, the total area of palm oil increased by 3.7 million hectares. Extensification or expansion of palm oil plantations turned out to be many "accused" and became the world's spotlight as from the conversion of forest land functions, so that there was a lot of deforestation to be converted into palm oil plantations.

Pressure from the European Union in particular, due to these conditions worsened the image of Indonesian palm oil which in turn affected the selling price of palm oil, both CPO (crude palm oil) and its derivative products. Improving the image is also not easy. One of the effective measures is to stop the extensification effort so that forest land remains as forest land and does not turn into palm oil plantations. Biochar can be an effective solution to this problem. By increasing the productivity of fresh fruit bunches (FFB) from the usage of biochar, new palm oil plantations do not need to be opened again. Assuming an average productivity increase of 20% occurs, CPO production will also increase by 20% or equivalent to 2 million tons. The increase would be equivalent to new land clearing of more than 2 million hectares. Certainly not a small land area. With the 20% increase in production, it is very likely that the national needs for CPO needs have been met and the same goes for the export market.

With the extensification of palm oil land of more than 1 million per hectare every year but the increase in palm oil fruit (FFB/fresh fruit bunch) production is only 11%, it is certainly less attractive and must be avoided, especially when the world's attention on deforestation is getting stronger. This also indicates the low productivity of the palm oil plantations. In fact, by improving soil quality, the productivity of palm oil fruit can be significantly increased and the clearing of new land for palm oil plantations can be avoided. Biomass wastes in palm oil plantations and in palm oil mills can be used for the production of biochar.

In palm oil mills, this biomass waste is easier to process in large quantities, especially empty fruit bunches (EFB). An average palm oil mill can produce 200 tons of waste per day of EFB. Meanwhile, in palm oil plantations, biomass waste, such as palm fronds, leaves and stems, is the raw material for the production of biochar. Palm oil trunks even have a lot of negative impacts when they are not treated adequately or are only left to rot in the plantation, giving rise to horn beetle pests, for more details read here. Optimizing the utilization of biomass waste has multiple benefits, not only preventing environmental pollution by the waste, and can be described as the scheme below.

In terms of technology, biochar production technology is also very varied, from simple technology (low tech, low cost) that is cheap to advanced high technology that is efficient, precise process control but at a higher price. In the palm oil mill, it will be effective to use high technology so that it can be integrated with the operations of the palm oil mill. The excess energy from the pyrolysis process will also replace boiler fuel which has been using fiber and palm kernel shells (PKS). There are indeed many advantages of palm oil mills when doing the production of biochar, for more details, please read here. Production of biochar with empty fruit bunches or EFB biochar is also more profitable than EFB pellets, a more detailed explanation can be read here. Meanwhile, for people who have palm oil plantations as part of society palm oil producers (Plasma) or independent plantations, they can use simple technology (low tech, low cost) for the production of biochar. Biochar production in a simple way can also take advantage of excess energy for various small business activities such as those carried out in Tanzania, Africa. In this way, the community in addition to producing biochar also gets a source of energy including reducing the use of firewood which can be obtained from cutting down trees in protected forests or reducing deforestation pressures.

Fertilizer is the highest cost component in the palm oil plantation operations. Besides being able to increase the productivity of palm oil fruit or FFB, Biochar can also reduce the need for the use of fertilizers. An increase in soil pH makes nutrients easily absorbed by palm oil trees and also increases soil microbial activity which increases fertility is one of the benefits of using biochar. And when the performance of the productivity level of palm oil plantations has been able to be achieved and maintained, a number of other improvements can also be made. From the industry point of view, raw materials are a vital factor in terms of availability, continuity of supply and quality, including palm oil mills. Moreover, the plantation aspect of CPO production holds a portion of 80% while the factory or the mill aspect is only 20%. This confirms that the plantation aspect plays a vital role in the supply of these raw materials, so that efforts to maximize productivity, including maintaining productivity level performance, are very important and a top priority. Meanwhile, the change in palm oil plantations from monoculture to polyculture (mixed plantation) is one of the further improvement that can be made. Extensive monoculture plantations have the potential to be susceptible to disease, so they need to be avoided. Technically, how much monoculture area is still effective, especially for palm oil plantations, there are no convincing findings.

Increasing Energy Efficiency in Palm Oil Mill Operations Using Pyrolysis

Energy utilization in the form of steam production which is then used for electricity production through steam turbines and generators, as well as the use of steam for steamming (sterilizing) fresh fruit bunches (FFB) are the main things in palm oil mill operations. This is because the need for electrical energy to power various mechanical equipment in the mill comes entirely from this electricity production. Electricity and steam for industrial processing are grouped under the utilities that support that industry. Meanwhile, in the sterilization process or the boiling of FFB, steam besides stopping the development of FFA (free fatty acid) and facilitating the threshing will also facilitate the CPO extraction process and processing the kernel (palm kernel). To produce steam and electricity, of course, energy is needed, namely heat. Steam is produced by the boiler in the form of superheated steam to drive steam turbines and generators to produce electricity and then steam from electricity production or low pressure steam is used for steamming (sterilization) of FFB.

The water after being treated so that it becomes BFW (boiler feed water) is then used for the production of steam and electricity. Heat energy to produce steam can be reduced in such a way with the use of a pyrolysis process (which means that it is not ordinary combustion), so that the heat requirement for the boiler furnace is getting smaller. The pyrolysis condenser will produce hot water so that it becomes preheating for the boiler. In pyrolysis a condenser is used to separate bioil and syngas (uncondensable gas). Preheating from the condensation process of the pyrolysis unit will then go to stage 2 preheating in the economizer of the boiler unit. Thus the temperature of the water entering the upper drum on the boiler is high enough, and the heat requirement to become superheated steam will be reduced. The palm oil mill uses a water tube type boiler as is commonly used in large industries and not a fire tube which is in the form of a shell and tube type heat exchanger with the tube submerged in water so that it does not overheat. In a water tube type boiler, it consists of an upper and lower drum (mud drum) which is connected to a pipe. The lower drum and water tube are fully filled with water, while the upper drum is only partially filled. With this arrangement, steam will pass through the mechanical separator on the upper drum, flow to the superheater and exit the boiler. Efficiency is the key word in production, including the use of energy in the production process of CPO or palm oil mills. The rule of thumb is an increase of 10 C in BFW is equivalent to increasing 1% boiler efficiency.

Typical of water tube boiler

Excess energy from the pyrolysis process should be used for fuel or energy sources in the boiler furnace. The use of excess energy from pyrolysis will also produce environmentally friendly flue gas emissions because the combustion of liquid and gaseous fuels will be cleaner than solid fuels. In this way, the palm kernel shell, which has been used for boiler fuel, can no longer be used. All these palm kernel shells or PKS can be sold directly and even exported to Japan and Korea. Of course, be a separate source of additional income. Palm kernel shells or PKS are competitors for wood pellets in the global market because they have many similar properties, but because palm kernel shells come from waste or palm oil mill sideproducts, the price can be cheaper, more information can be read here. The use of slow pyrolysis for biochar production is the best option compared to similar technologies such as fast pyrolysis and gasification, more details can be read here. Palm oil mills or companies will get a lot of benefits from biochar production, for more details can be read here.

Benefits of Palm Oil Company When Produce Biochar

There are at least four things that become motivation for biochar production, namely as in the chart above. There are a number of slices that make the impact of biochar application multi-benefits, which is very much in line with today's world problems, namely climate change and global warming. Biochar has also been accepted as an instrument to reduce the concentration of CO2 in the atmosphere which causes the two big problems above, namely in 2018 biochar was included in the Intergovermental Panel on Climate Change (IPCC) as one of the negative emissions technologies (NETs). Biochar application is a carbon negative scenario because biochar can absorb CO2 from the atmosphere. This is slightly different from the use of biomass fuels such as wood pellets, wood briquette and palm kernel shell (PKS) in industrial boilers or power plants, which are carbon neutral scenarios. Indeed, basically there are 3 big scenarios to reduce the concentration of CO2 in the atmosphere, namely increasing the efficiency of equipment that uses fossil fuels, using carbon neutral fuels and carbon negative scenarios such as biochar.

Palm oil trees are known to require a lot of water and fertilizer to maintain the life sustainability and productivity of their fruit, so practical efforts in the form of increasing fertilizer nutrient efficiency and increasing fruit productivity are important. Besides that, palm oil mills produce a lot of biomass waste, especially empty fruit bunches (EFB ) and mesocarp fiber, which are very potential for biochar raw materials. The biochar is then applied in palm oil plantations which can be used with chemical fertilizers or with compost / organic fertilizers.

Pyrolysis and gasification technologies are commonly used for the production of the biochar. Apart from producing biochar by pyrolysis or gasification, energy is also produced which can be used for the business development of the palm oil industry or for electricity production. Production of PKO (Palm kernel oil) from kernel processing at KCP (kernel crushing plant) or production of torrefied PKS from PKS processing with torrefaction can be done by utilizing excess energy from the production of biochar. Most of the palm oil mills or CPO mills do not have kernel processing or KCP to produce PKO. And by making torrefied PKS, the caloric value of PKS will increase, it is easy to downsizing (increased grindability), for example in the use of cofiring and does not absorb water (hydrophobic property). In general, palm oil mills will have many advantages, both economically / financially and environmentally, with this biochar production.

Apart from being used for business development like the diagram above, excess energy from pyrolysis or gasification can also be used as boiler fuel in the palm oil mill. In this way the energy to heat the boiler, which is usually with palm kernel shell and mesocarp fiber, can be replaced by energy from pyrolysis or gasification. After that, all of the palm kernel shells / PKS can be sold or exported, thus providing additional profits for the palm oil company. The need for biomass fuel, especially palm kernel shell / PKS, is predicted to increase, both in the domestic market and in the export market. Japan is currently the largest consumer or user of palm kernel shells and it is predicted that the demand will also increase. Japan will also impose stricter standards on imports of palm kernel shells to ensure environmental sustainability by applying the GGL (Green Gold Label) certification which will be effective starting April 2023. This is like the wood pellets with FSC certification. If anyone is interested in an economic analysis of the use of biochar in palm oil business, please contact us.

Biochar to Increase Biogas Production

Charcoal (biochar) is the raw material for the production of activated carbon. The production of activated charcoal itself goes through two main processes, namely carbonization (pyrolysis) and activation. The surface area of charcoal (biochar) is also smaller than that of activated carbon, but larger than the raw biomass. The carbonization process increases the surface area of the raw biomass. The ratio of surface area between raw biomass, charcoal and activated charcoal is approximately 25 m2 / gram, 200 m2 / gram, 2000 m2 / gram. The larger the surface area of the biomass material that is inserted into the biogas reactor, the greater the penetration of bacteria into the substrate so that the fermentation process that occurs is more perfect so that biogas production will increase. Biochar itself does not participate in fermentation because the main component is stable carbon, while hemicellulose, cellulose and lignin have been decomposed during the carbonization process.

Another example is the addition of biomass briquettes to the biogas reactor, briquetting processs with high pressure and heat also open pores or expand the surface of the biomass, so that biogas production also increases, for more details, read here. The addition of biomass briquettes to the biogas reactor will also increase the C / N ratio, even biochar and activated charcoal have high carbon (C) content.

Charcoal (biochar) has been widely used in the agricultural world to repair damaged soil / soil amendment and thus increase fertility. Good soil fertility will also increase agricultural production. The biochar becomes a home for soil microbes, so that organic materials or compost will break down more completely and be absorbed by plants more as plant nutrients. The charcoal (biochar) pores are the home for these microbes. The more pores, the more microbes will inhabit the biochar as their “house”. The same principle applies to the biogas unit. Another bonus of using biochar is that it absorbs CO2 from the atmosphere, thereby contributing to lowering the greenhouse gases that cause climate change and global warming.

Research in Germany shows that adding 5% biochar to a biogas reactor increases methane production by 5% - based on the dry matter of biochar to the substrate. But when the amount of biochar became 10%, it turned out that no more methane was added. This shows that the optimum condition for adding biochar is the amount of 5%. The microbes in the biochar increase the volume of microbes in the reactor so that the production of biogas or especially methane also increases up to 5%. Biochar itself is not decomposed in the fermentation process. 

Meanwhile, the addition of biomass briquettes per 1 tonne of briquettes will increase biogas production by 400 Nm3. This is because in the biomass briquettes, both cellulose, hemicellulose and lignin have not been decomposed, thus adding to the substrate in the biogas reactor. Whereas in biochar, both cellulose, hemicellulose and lignin have been decomposed during the thermal carbonization process, so there is practically no additional substrate, but only microbial addition occurs in the biochar pores.

The important thing about the addition of biochar is that the compost or digestate produced is of better quality with the addition of the biochar. Biochar will make the compost which is produced as a slow release organic fertilizer. This further encourages biochar production, especially for palm oil companies that care about environmental issues and even strive for zero waste conditions.

Palm oil mills have the potential to apply biogas and biochar units. Solid wastes such as empty bunches and mesocarp fiber can be used for biochar production. Palm oil mills can even replace the furnace in the boiler with a gasifier or pyrolyser. This becomes more profitable because in addition to heat energy being used for production of steam which is used for power generation and sterilization of fresh fruit, biochar will also be produced. The biochar produced is then used to increase biogas production and improve the quality of the compost, as well as a fertilizer mixture in palm oil plantations. And even the potential use of biochar to save fertilizer on large palm oil plantations, for more details can be read here.