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. 

Liquid Smoke-Based Biostimulant (Foliar Fertilizer) for Application to Palm Oil Plantations Using Drones

In palm oil plantations, fertilizer is the highest cost component of their operations. Therefore, various efforts are made to optimize fertilization to ensure its maximum efficiency, including the use of slow-release fertilizers. For more details, read here. To maximize fertilization and maximize fresh fruit bunch (FFB) yields, the use of foliar fertilizers is also worth considering. Liquid smoke (pyroligneous acid) is one such foliar fertilizer, although a more accurate term is biostimulant (booster).

This is because liquid smoke does not provide nutrients such as nitrogen (N), phosphorus (P), and potassium (K). However, liquid smoke acts as a biostimulant, plant growth regulator (PGR), and natural protectant, promoting optimal leaf growth. Optimal leaf growth exponentially increases the growth of all plant organs, including stems, roots, flowers, fruit, and so on. Leaves are the primary "kitchen" of a plant, so leaf health determines the health of the entire plant system. Optimal leaf growth also increases the efficiency of fertilizer absorption (a "pump engine" effect) in the soil.

Furthermore, liquid smoke is not only used as "leaf fertilizer", it turns out that liquid smoke also functions as an organic pesticide (fungicide/insecticide). This repels pests (such as ticks and flies), and prevents leaf diseases. The phenol and acetic acid content is toxic to insects (aphids, thrips, caterpillars) and is effective in suppressing fungi that cause plant diseases. And the distinctive smell of smoke makes insects reluctant to approach and lay their eggs on the surface of the leaves. In addition, its binding properties make it difficult for pathogenic fungal spores to attach and develop on the surface of the leaves

Regarding this dual function, the use of liquid smoke for application to leaves (foliar) can be prioritized, whether it is more specifically used as a "foliar fertilizer" or as a biopesticide. This requires a number of adjustments such as dosage, additional formulations and application time. To maximize the function of liquid smoke as a leaf fertilizer, you must mix it with additional nutrients (such as liquid organic fertilizer / LOF) and apply it when the leaf stomata are fully open. Liquid smoke is able to reduce water molecules. When diluted or mixed with Liquid Organic Fertilizer (LOF), the nutritional content of the fertilizer becomes easier to enter and be absorbed through the stomata (leaf mouth). Meanwhile, to maximize its function as a biopesticide, liquid smoke needs to be combined with other vegetable pesticides. The frequency of spraying for prevention is once a week, while pest attacks are high, namely 2-3 times a week until the pest population is under control.

The use of drones for spraying pesticides and liquid fertilizer has been widely used on various agricultural crops such as rice, corn, sugar cane and palm oil. More specifically in palm oil plantations, drone applications are a modern solution for spraying fertilizers and pesticides. And in Indonesia more than 80% of drone applications are for the forestry and agricultural sectors. Efficiency factors (time, energy, operational costs, fertilizers, pesticides) and precision are the main driving forces for this drone application. This means that drone technology is expected to be an effective solution in controlling pests and diseases, fertilizing and cultivating palm oil plants. Drones are effective in increasing plantation efficiency, especially in areas that are difficult to reach. As a technology, various improvements have been made to improve its functions such as carrying capacity, spray speed, safety features and work efficiency. The use of drones supports precision agriculture and global food security with an environmentally friendly technological approach.

Spraying liquid fertilizer on the underside of leaves (underside spraying) using a drone requires special techniques. This is because drone propellers naturally produce strong downwash. This downwash effect is used to gently move and turn the leaves, so that the droplets can hit the bottom of the leaves. This is because on the bottom of the leaf, where the stomata are located the most are gathered around 80%. The spray texture is also made into mist mode (the finest dew) so that the liquid sticks evenly and doesn't drip onto the ground. Next, the drone's height, speed and nozzle angle need to be adjusted in such a way to achieve this goal. Environmental factors in the form of strong winds need to be avoided so it is necessary to adjust the right time and conditions.

As the use of biochar grows as a solution for health and soil fertility as well as a climate solution, this should also be the case with the application of liquid smoke. Liquid smoke as a by-product in the form of a liquid product from biochar production will increase along with increasing biochar production. Liquid smoke as a product produced from biomass raw materials through a pyrolysis process also encourages the use of natural materials based on renewable resources so that it is environmentally friendly and sustainable. 

Electricity Production from Pyrolysis, Using a Gas Engine or ORC Generator?

The more efficient the equipment, the greater the benefits or profits that can be obtained. This includes equipment for biochar production, namely pyrolysis. The more efficient the pyrolysis equipment, the cheaper it will be to produce biochar but also produce development products. An example is the use of byproducts from the pyrolysis process such as syngas, biooil, pyroligneous acid and excess heat. Harvesting or utilizing energy from waste heat sources that would normally be wasted is also part of efficiency as well. A number of products that can be used for energy production can be used for electricity production, namely syngas, biooil and excess heat. But there are a number of technologies for producing electricity, so which one do you choose?

A. Gas Engine

Gas engines such as the GE Jenbacher are commonly used to produce electricity from biogas. Biogas, which is a product of bioprocess, has a very dominant methane gas content, while syngas from pyrolysis, which is a thermal process, contains only a small amount of methane and more hydrogen (H2) and carbon monoxide (CO), this means that gas engines are not suitable for producing electricity from syngas pyrolysis. Apart from being suitable for biogas, gas engines such as the GE Jenbacher are also suitable for natural gas, which also contains methane gas.

B. ORC (Organic Rankine Cycle)

The main difference between the Organic Rankine Cycle (ORC) and the ordinary Rankine cycle lies in the working fluid and the temperature of the heat source used. ORC was specifically designed as a modification of the conventional Rankine cycle. The difference with the ordinary Rankine Cycle which uses steam from the boiler as the working fluid which is widely used in large capacity coal powerplants, the ORC uses a working fluid in the form of an organic fluid which has a low boiling point such as hydrocarbons or refrigerants. This low boiling point means that you can use a heat source whose temperature is not too high, such as waste heat or residual heat and so on.

And because there are many organic fluids available, selecting organic materials as suitable working fluids for ORC is no less important. In fact, the choice of working fluid for the ORC generator is very crucial because it affects thermodynamic efficiency, operational costs and safety aspects. The main factors considered are the thermophysical properties of the fluid, compatibility with the heat source, environmental impact, and commercial availability (economic aspects). So the selection of ORC fluid must balance energy efficiency, safety, environmental impact and cost.

Waste heat from pyrolysis can be recovered and used for electricity production with this ORC. Likewise, pyrolysis byproducts that can be used as energy sources are excess syngas and bio-oil. The excess syngas and bio-oil are used as fuel and the heat is used as an energy source for the ORC generator. Basically, the selection of an ORC power plant is based on electricity needs and available energy sources. 

For small electricity needs, namely in the range of 0.5 MW - 10 MW and low temperature energy sources, namely those whose temperature is below 350 C (low to medium temperature range (80 C - 350 C)), then the choice of ORC is suitable. As a comparison, steam turbines require temperatures well above 400 C and a power output of 10 MW to above 1,000 MW (as in coal-fired power plants or nuclear power plants). But why do almost all palm oil mills (CPO / crude palm oil mills), even though their electrical power production is small or an average of less than 5 MW, still use steam turbines? For an explanation, read here.

The application of an Organic Rankine Cycle (ORC) generator as waste heat to power (WHP) from the pyrolysis process is a very effective combination to increase the total energy efficiency of the system (co-generation). And modern pyrolysis units are widely used in continuous system biomass pyrolysis, namely for biochar production, which work autothermally or self-sustainably, so it is possible that the pyrolysis unit can also operate independently from the electricity generator from the ORC. This means it will reduce operational costs, because the electricity to run electric motors, pumps and so on comes from its own production. In other words, the pyrolysis unit operates independently without depending on the electricity network or PLN (Indonesia state owned company). From a climate perspective, these conditions are ideal, because the energy source comes from renewable sources (carbon neutral) and if biochar is used for carbon sequestration it means it is carbon negative. Optimizing the system so that it produces an optimal and profitable configuration is the task of engineers.

An American company, namely Quonset Soil Solutions, LLC in Rhode Island, has recently successfully installed an ORC unit to harvest waste heat from their pyrolysis unit with a capacity of 1.8 MW. Apart from that, several pyrolysis units in Europe are also reported to be using ORC with a smaller capacity. These successes will inspire and the installation of ORC units as part of biochar production with (slow) pyrolysis will continue to grow.

Conclusion:
-The ORC system is highly recommended for continuous scale pyrolysis plants (not small batch types) because it is able to convert heat pollution (waste heat) into valuable electrical energy assets constantly. ORC operations are environmentally friendly and support decarbonization targets.

-The ORC generator from waste heat pyrolysis is an efficient, safe and sustainable solution for generating electricity from waste heat energy (residual heat). This technology is also ideal for various industries that produce intermediate heat, so that energy is not wasted.

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.