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. 

Not Only Reduce Steam Cost, but Also Reduce Water Treatment Cost for Boiler Feed Water and Even Also Increase Revenue with EFB Cogeneration

Even though biomass waste is abundant in palm oil mills, the use of efficient boilers is also needed. Efficient use of biomass waste according to the type/specifications will also provide additional benefits for palm oil mills. The longer the biomass waste, the more diverse its uses, ideally even zero waste. Apart from mesocarp fiber which is usually used 100% and added with a number of palm kernel shells (PKS) and sometimes also a few empty palm fruit bunches (EFB), an efficient boiler will optimize the type and amount of biomass. For example, PKS as a commodity that can be sold are used as little as possible for boiler fuel, so that more can be sold which increases the profits of the palm oil mill.

Photo taken from here

Is a utility business like buying steam from another company needed? Utility businesses like selling steam, heat, or electricity are indeed starting to emerge; for more details, read here. Certain companies are greatly helped and receive utility products according to their wishes. They do not want the hassle of operating a boiler, including sourcing its fuel. However, for palm oil mills that in their operations produce a lot of biomass waste that can be used as fuel, it is more practical and efficient to operate their own boiler. And this has been a common practice in palm oil mills for a long time. Therefore, cooperating with a utility company to obtain steam and electricity is not an effective solution. The effective solution is the use of an efficient boiler as explained above.

Apart from that, regarding boiler feed water to increase efficiency or reduce costs and be environmentally friendly, AOP (Advanced Oxidation Process) technology, namely an electrochemical device, is used. With this method, apart from not using chemicals so it is environmentally friendly, it will also increase the service life of the RO (reverse osmosis) membrane which is the heart of the water treatment unit. Not only will the RO membrane have a longer service life, but also the activated carbon filter and ion exchange resin, which are stages of water treatment. Apart from being environmentally friendly, this technology is also more in line with the sustainability mission.

And regarding boiler operations, even to increase the volume of PKS that can be sold, cogeneration of empty palm fruit bunches (EFB) can be carried out. In this way, the EFB, which have been waste biomass which pollutes the environment and which most palm oil mills have not yet processed, are then burned to produce heat and potassium ash. The potassium content above 30% in the ash will make quality fertilizer that can be sold or used in your own plantation. Meanwhile, the heat from burning EFB is used as additional energy for the boiler (cogeneration). In this way, 100% of PKS can be sold and even exported.

If the use of PKS for boiler fuel reaches 50% then using this technology means that 50% of the  PKS can be recovered or taken back or 100% of the PKS can be sold or even exported. For example, a palm oil mill under normal conditions can sell 2,000 tons of PKS/month, then by using this technology the palm oil mill can sell 4,000 tons of PKS/month. Of course the increase in PKS supply volume is very significant to increase income, for more details read here. 

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.

Processing of Empty Palm Fruit Bunches (EFB) for Ash Production as Potassium Fertilizer and Energy

Palm oil mills produce a large amount of biomass waste, and one of the largest in their daily operations is empty fruit bunches (EFB). Comprising approximately 22% of the fresh fruit bunches (FFB) processed by the mill, the volume becomes enormous and piles up daily if not managed properly. For example, a palm oil mill with a capacity of processing 60 tons of FFB per hour for 20 hours per day produces 264 tons of empty fruit bunch waste per day (approximately 6,600 tons per month and 79,200 tons per year). This enormous amount would resemble a hill if piled up in one place.

Incinerators have recently become popular, particularly in Indonesia, for processing empty fruit bunches due to their speed and practicality. Furthermore, the ash produced by burning them can be used as fertilizer due to their high potassium content. However, these incinerators produce exhaust emissions that pollute the environment, including black smoke and particulate matter. These emissions, which pollute the environment and exceed the threshold permitted by the Ministry of Environment (KLH), have led to the prohibition of incinerators. This ban has led to an increasing number of unmanaged empty fruit bunches. Using empty fruit bunches for mulch is also less effective, and composting, a biological process, takes a long time.

Video link for conventional EFB incinerator here

This problem demands an immediate and effective solution. The quickest practical solution is to upgrade the incinerator to make it environmentally friendly or to reduce emissions below the required threshold. This can be achieved by using adequate emission control devices to meet these environmental requirements. While many emission control devices are available, cost and target output are crucial considerations when selecting them. This approach not only addresses the problem of empty fruit bunches, but the resulting ash can also be used as a potassium fertilizer.

Furthermore, by upgrading the incinerator with emission controls (basic type), the equipment can be developed into several types, as follows: the second type is a cogeneration boiler for palm oil mills, allowing 100% palm kernel shell (PKS) to be sold, even for export. The third type is by adding a new boiler and steam turbine for electricity production, which is then sold to PLN (Indonesia State Owned Electricity Company) under a power purchase agreement (PPA). The fourth type is equipped with waste heat recovery equipment, allowing for more general use. This also means the combustion process in the upgraded incinerator can also be upgraded so that the combustion process can run optimally. Several combustion technologies, such as chain grates, step grates, or reciprocating grates, can be considered to achieve maximum performance, including the removal and handling of ash product.

Empty fruit bunches (EFB) processing can vary, although the primary focus is addressing environmental pollution caused by them. However, their large volumes certainly represent a potential raw material for processing units. Therefore, in addition to addressing this waste, the technology used must also provide financial benefits. Of the numerous EFB processing technology options, the cost-to-benefit ratio of a technology application will be a crucial consideration for EFB processing.

In addition to combustion using conventional or this upgraded incinerator, thermal processing routes also include pyrolysis, with slow pyrolysis specifically for biochar production and fast pyrolysis for bio-oil production. Another pyrolysis variant is mild pyrolysis or torrefaction for the production of torrified biomass. Then there's gasification to maximize gas (syngas) production from biomass. Furthermore, empty fruit bunches of palm oil can be used as fuel or an energy source. To facilitate handling, storage, and reduce transportation costs, empty fruit bunches need to undergo biomass densification technology, with the final product being pellets or briquettes. 

Optimization of Palm Oil Mill Operations to Maximize Profits by Utilizing EFB Waste

As a profit-oriented company, palm oil companies will also do various things necessary to maximize their profits, both in the operations of their palm oil mills and on their plantations. The more efficient the operations of the palm oil mill, as well as on its plantations, the higher the profits obtained. Minimizing the environmental impact of waste produced, even zero waste, and becoming part of responsible and sustainable environmental management practices, including part of climate solutions, are important parts of this industry that cannot be abandoned. That is why palm oil mills must innovate to achieve optimal conditions. To achieve these conditions, it can be done by evaluating current practices and finding better solutions.

CPO (crude palm oil production) requires steam for the sterilization process. This is why palm oil mills definitely need boilers for their production process, for more details read here. Steam from the boiler is also used for power generation with steam turbines to drive generators. The operation of the boiler is generally carried out by burning fiber (mesocarp fiber) and some palm kernel shells / PKS, so that some palm kernel shells /PKS can still be sold or even exported. This common practice in palm oil mills has also been running for decades, but it turns out that there is still a lot of biomass waste from palm oil mills that has not been utilized, especially empty fruit bunches or EFB (empty fruit bunches) which account for around 23% of the fresh fruit bunches (FFB) processed. These EFBs are usually only piled up behind the palm oil mill and tend to pollute the environment.

The EFB can be processed into biochar. Biochar production with thermal processes, either pyrolysis or gasification, will produce energy as cogeneration in palm oil mills. Cogeneration is the right solution for biochar production while supplying energy needs for boiler operations. In this way, 100% of palm kernel shells / PKS can be sold or even exported, meaning that palm oil companies' profits are greater. But to maximize biochar production, pyrolysis is the right choice. This is because gasification technology is to maximize gas products while pyrolysis is to maximize solid products (biochar). By-products from pyrolysis are also beneficial for the palm oil industry.

Empty fruit bunches (EFB) are solid waste from palm oil or CPO production which is the largest in number. This is what makes many machine manufacturers make these EFB processing machines. Most of the machines made are equipments for cutting and pressing the EFB so that the water content decreases and the material size becomes smaller. However, both the water content and the size of the EFB as the output of the machine or equipment still do not meet the requirements to be further processed into biochar. The typical output is more than 4 inches and the water content is more than 45%. EFB must have a low water content of 10% and can be less than 1 inch for biochar production or as fuel in the boiler.

  

To obtain the EFB with a dryness level or water content of 10%, waste heat recovery from palm oil mills can be utilized for the drying process. Other biomass waste from the palm oil industry can be utilized as fuel or a source of heat energy for drying the EFB. By utilizing these biomass wastes, mill operations can be more efficient so that profits are maximized and environmentally friendly with zero waste. 

Cogeneration in Palm Oil Mills with Pyrolysis, Initial Steps in Biochar Production and Implementation

The analogy is like cofiring carried out in coal-fired power plants by mixing biomass fuels with a certain ratio as an effort to decarbonize the energy sector in power plants. While in palm oil mills, cogeneration with pyrolysis is an innovative initial step to enter the carbon negative era with the application of biochar, the main product of pyrolysis. And because all palm oil mills use biomass fuel for their mill operations, they are already based on carbon neutral fuel, unlike coal-fired power plants which are based on carbon positive fuels because they come from fossils.

Unlike cofiring which mixes coal and biomass fuels with a certain ratio and then burns them together in a furnace such as pulverized combustion, cogeneration is done by producing energy separately but the energy output is for the same use or especially the same boiler. This is done because the types of fuels may be different, such as solid fuels with liquid fuels or the technology for producing the energy is different. With this cogeneration, it means that not all energy is produced from one energy source or energy from cogeneration is a secondary energy source to meet total energy needs, and in the case of cogeneration in this palm oil mill, energy from combustion is still the primary energy.

Then why not just do full pyrolysis? It is easier, gradually for palm oil mills to adopt pyrolysis technology and its characteristics. Because (slow) pyrolysis aims to maximize solid / biochar, the by-products in the form of excess energy (syngas and biooil) as a source of boiler fuel, the calorific value is not as much as combustion which is indeed intended to maximize heat. Only about 1/3 of the excess energy contributes (cogeneration) as boiler fuel. In other words, if full pyrolysis is carried out directly, the amount of biomass as raw material for pyrolysis becomes 3 times greater or the pyrolysis unit becomes very large so that all palm oil mill biomass waste is used, and the mill cannot sell its palm kernel shells.

What are the benefits obtained by palm oil mills if they carry out cogeneration with pyrolysis for biochar production? Among the biochar products, it can save fertilizer use in oil palm plantations, overcome the problem of empty oil palm bunches (EFB) so that palm oil mills can achieve zero waste, palm kernel shells (PKS) that have been used for boiler fuel can be sold to increase income, the productivity of fresh fruit bunches (FFB) of palm oil increases, the application of biochar in palm oil plantations is also a climate solution (carbon sequestration / carbon sink) so that it can get carbon credit compensation and with good waste management, even zero waste and the application of biochar in palm oil plantations, palm oil companies will get a good image in terms of the environment and sustainability.