POME Sludge Pellet

Processing palm oil mill effluent (POME) is one of the mandatory requirements for palm oil mills. This requirement becomes a criterion whether the palm oil mill in question has a good environmental concern, especially its waste processing sector. The liquid waste of oil palm mills is one of the large quantities of palm oil mill waste. Almost all palm oil mills always have wastewater treatment ponds. Every ton of FFB (Fresh Fruit Bunch) produces 700 liters (0.7 m3) of liquid waste so that if the plant has a capacity of 60 tons / hour FFB and operates 20 hours per day, the volume of liquid waste produced reaches 42,000 liters / hour (42 m3 / hour) or 800,000 liters / day (800 m3 / day). The method of processing wastewater can be like the diagram below.

Biosolid in the form of accumulated sludge can be processed further for biogas production, with by-products in the form of treated sludge, which is usually an organic fertilizer, can also be directly used as fuel. Instead of just being thrown away, the biosolid can be biomass densified into pellets. By becoming a pellet besides facilitating handling, storage, transportation and utilization. The pellet production process from POME sludge is also almost the same as the production of wood pellets. The production of POME sludge pellets is also a solution to overcome organic waste effectively and cheaper than processed further into biogas. Biogas production from POME with both the covered lagoon and CSTR (stirred tank continuous reactor) still requires expensive investment, so there are still very few oil mills in Indonesia that do it. And if the POME sludge is left alone in the waste pond so that there is aerobic fermentation it will produce methane gas which damages the ozone layer in the atmosphere.

If every month from a palm oil mill is produced 2,000 tons of POME sludge and an area such as Riau which has around 300 palm oil mills, then the potential of POME sludge reaches 600,000 tons and this is equivalent to 300,000 tons of POME sludge pellet. Whereas if calculated nationally with the number of oil mills reaching 1,000 units, the potential of POME sludge will reach 2,000,000 tons or equivalent to 1,000,000 tons of POME sludge pellet. Interestingly, POME sludge pellets also have a fairly high calorific value, which is about 4000 kcal / kg. This can happen because POME sludge still contains palm oil. With such a high calorie content, the POME sludge pellets are attractive. Besides being able to be used by various industries as fuel, the selling price of POME sludge should also be quite attractive because of its high energy content. The hope is POME sludge pellet will become a new and renewable energy amount that is very abundant in Indonesia. And if it is used as industrial fuel which means substituting fossil fuels, then it also reduces the use of fossil fuels, is environmentally friendly and carbon neutral.

Biomass : The Sexy Savior

In terms of environmental aspects biomass is a carbon neutral energy source, this is different from fossil fuels, especially coal, which is a carbon positive energy source. The more coal is consumed (burned) for energy sources, the higher the concentration of greenhouse gases, namely CO2 in the atmosphere. The higher concentration of CO2 gas in the atmosphere means increasing the temperature of the earth which causes the phenomenon of climate change and global warming. According to data from the Mauna Loa observatory in Hawaii, the concentration of CO2 in the atmosphere has reached more than 400 ppm and it is in a state of danger to the environment. As a global problem, of course, the global approach taken to solve the problem is like the annual climate conference, which in 2018 yesterday or the 25th was held in Katowice, Poland.

Indonesia as a tropical country is more suitable to develop biomass as its energy source than solar energy. Why is that? For more details, please read here. In addition, the position on the equator also has great potential as the largest producer of biomass, more details can be read here. Agricultural, livestock and forestry wastes are one of the sources of the biomass. Agricultural wastes such as rice husks, palm oil empty bunches, coconut fiber, corn cobs and so on are also very large in number. But it can also be cultivated specifically by making energy plantation. There are millions of hectares of land available that can be used for the energy plantations. Coal mine holes that reach 8 million hectares if reclaimed are also potential for the development of these energy plantation, for more details can be read here. With the development of energy plantations, besides getting energy, it can also be used as a means of water conservation and meat production by integrating with livestock such as sheep or cattle. Not only that honey production with bee farms that use flowers from energy plantation is also very potential. For more details can also be read here. The potential for biomass energy in Indonesia is also very large, according to ESDM when it is converted to electricity reaching approximately 50 GW but only 3% is used.

Technically, biomass fuels also have many advantages, such as there is no problem with fly ash, the sulfur content is very small and the ash is not hazard / poisonous material but can even be used for fertilizer crops. Utilization of biomass as an energy source is also nothing new, even before coal is used massively, the biomass fuels is the main energy source, for more details can be read here and here. Not only that, even the European Union has implemented various policies to encourage the use of renewable energy massively such as the 20-20-20 target or RED (Renewable Energy Directive) I, namely increasing the efficiency of energy use by 20%, using renewable energy reaching 20% ​​and the target has been applied in 2020. Of the 20% of renewable energy 80% of them are biomass energy. And because the target is almost over, they are preparing a replacement for RED II with a portion of renewable energy increasing by almost 1/3 with a target time of 2030 and a portion of biomass energy still reaching around 80%. Another example is Japan, which since the accident occurred with the Fukhushima nuclear power plant in 2011, then biomass energy is one of the main energy sources in the country. Biomass energy does have an advantage in its utilization because it is not affected by weather as well as wind and water energy. And more importantly the development of biomass energy in line with the Qur'an for more details can be read here.

Production of Briquettes from Corn Cobs

Although corn cobs can be made pellet, briquette production can be more interesting. Why is that? This is related to the market segment and the technical specifications of the corn cob briquettes. The household segment, and SME may be the biggest user of corn cob briquettes. One of the obstacles in this segment is the unavailability of stoves and supply of corn cob briquettes. The second reason is that by making briquettes the density can be twice that of wood pellets. This will make cheap transportation costs as well as higher energy content.

A number of regions in Indonesia which are agricultural centers will produce abundant corn cobs. If this waste is utilized, it certainly reduces environmental pollution and simultaneously provides economic added value. Dependence on fossil fuels can also be reduced gradually. Aesthetically when made briquettes also make storage easier, cleaner, attractive and easy to use. Efforts towards the use of corn cobs should be a concern for corn production centers. With corn cob briquettes also energy costs or the price can be cheaper than LPG.

Why is coal briquette less attractive to the public? This is because coal briquettes damage the flavor of cooking, especially high sulfur content. Roasting food with coal briquettes makes food not tasty. This is different when using corn cobs as raw material for briquettes. With a very low sulfur content and the sweet aroma of corn making grilling food with corn cob briquettes makes the food taste more delicious. As sawdust briquette can be processed further sawdust charcoal briquette, corn cob briquette can also be processed further into corn cob charcoal briquette. With charcoal briquette made, fixed carbon increases, volatile matter decreases and automatic calorific value also increases, so that the quality increases, among others, not smoky and can be used to bake longer.

Energy Plantation for Coal Mine Reclamation

Indonesia as one of the largest coal producers in the world, turns out to leave environmental problems in its mining activities. It is estimated that around 8 million hectares or around 3/4 of Indonesia's palm oil plantation are former coal mine holes. The holes become a kind of lake that also often takes casualties. The regulations that apply are reclaiming the hole by returning the soil excavated after the coal deposit being extracted. In practice there are still very few who do this so that holes like lakes are still scattered everywhere. Of the very few, most of them only do it symbolically, meaning that reforestation of reclaimed land is only done in certain areas.

Energy plantations with fast rotation plants and leguminoceae groups such as calliandra and gliricidae are the right solutions to reduce these environmental impacts. After the reclaimed energy plantation can be made in the area of ​​the former coal pit. With an area of ​​thousands to millions of hectares, the woody biomass production from the energy plantation will also be large. The wood is then used as an energy source too. Coal companies are basically energy companies, so it will be in line if it also produces wood as an energy source as well. The difference is that wood from the energy plantation is renewable energy, is a carbon neutral fuel and sustainable. Reclamation with energy plantation also provides a positive image for the company. In order to provide high added value, the wood can be processed into wood chips or wood pellets.

Why are fast-rotating plants from the leguminoceae group such as calliandra or gliricidae chosen as energy plantation tree species? This is because a number of advantages of these plants include pioneer plants and are very easy to grow, easy to care for, can be harvested quickly and with roots that are symbiotic with azetobacter so that they can bind nitrogen from the atmosphere to increase soil fertility. The condition of infertile reclamation land can also be repaired with the energy plantation. Indonesia's position on the equator is also very supportive for the production and use of energy from biomass, especially energy plantations. There is a lot of cloudiness because the island nation makes solar energy use of solar panels less suitable to be applied in Indonesia, for more details can be read here.

The use of renewable energy is gradually starting to replace fossil energy. Renewable energy, especially biomass, is environmentally friendly and sustainable. The coal power plant can also gradually use biomass as its fuel by means of cofiring. Cofiring is the easiest and cheapest way for coal power plants to go to biomass power plants. In this way automatic waste of fly ash will also be reduced. Conversion of up to 100% biomass or full firing is the target for the coal power plant. In addition, power plants also do not have to be centralized with large capacity, for example, hundreds of MW or thousands of MW, but more scattered with small to medium capacity with biomass fuels, especially those that are intensively cultivated with energy plantations that can be made in various corners of the archipelago. Gasification and fluidized bed technology are a number of technologies that can be used for small and medium scale power plants and use wood biomass as fuel. It is not even impossible that the power plant is only the size of a refrigerator.

Sago Waste For Sawdust Charcoal Briquette

Sago forests are spread mainly in the regions of Indonesia, Malaysia and the Philippines with Indonesia, especially Papua as the owner of the largest sago forest with a forest area of ​​1.2 million hectares or almost 50% of the world's area. Although sago plantations have begun to be made, most of them are still in the form of forests. In areas that have made sago plantations, the processing of sago products produced is also better. Sago has a very important role in food security, especially in areas such as Maluku and Papua. People in these areas eat sago as their staple food. Food security according to Law No. 7 of 1996 and PP 68 of 2002 is a condition of fulfilling food for households which is reflected in the availability of sufficient food, both in quantity and quality, safe, equitable and affordable. In addition, sago trees also have environmental benefits such as erosion, water absorption and greening. Food conversion from sago to rice will encourage the conversion of sago forest to rice fields and that also eliminates the environmental benefits of sago forests. The loss of environmental benefits from sago forests also means inviting potential natural disasters. It should not be necessary to convert food from sago to rice for these areas but instead develop and preserve the potential of sago trees in these areas and is even possible as an export commodity. Based on a number of analyzes, the use of sago from local locations will be able to be self-sufficient in the area, for example in Maluku and Papua.

The use of sago is mainly for carbohydrate production as a staple food. Sago starch is taken from the extracted part of the sago stem so that the sago starch and residue are separated. In a number of areas the process of extracting sago starch is still very simple, namely the sago stem taken from the rich part of the sago, reduced in size for example by grated and mixed with water and then squeezed by hand and sago starch taken out then as the sediment. With the help of mechanical tools the extraction process can be easier and faster. The sago production process produces a number of biomass wastes that actually have economic potential. The waste of sago bark and sago residue is a potential raw material for the production of sawdust briquette charcoal. At present most of the waste is still untapped and only pollutes the environment.

The production of sawdust charcoal briquette from sago waste is almost the same as the production of sawdust charcoal briquette from raw materials of wood waste in general. The sago bark needs to be reduced in size (size reduction) to the size of sawdust while the residue is not necessary because the particle size is relatively small. The next stage is drying with a dryer and the most widely used today is the rotary (drum) dryer. After the material is dry enough, it is then temporarily stored and then fed to the screw extruder and produced like sawdust briquette. At this stage the production process stages are very similar to wood pellet production, the difference is for the production of sawdust briquette using a screw extruder, while for wood pellets with pelletizers. To become sawdust charcoal briquette, the sawdust briquette is then carbonised in a carbonization furnace which takes around 10 days.

Why not to wood pellet production? Reasonable question of it. Although the sago waste can be used for wood pellet production, the high chlorine content makes it less acceptable, especially for the export market where the end user is a (pulverized) power plant. If wood pellets from sago waste are intended for the domestic market for use in a number of SMEs it is also not a problem. While the absorption of the domestic market is still small, then some wood pellet producers are still a priority for the export market with the requirements of technical specifications quite stringent. Based on these conditions the production of sawdust charcoal briquette is more an option, and besides that sawdust charcoal briquette production equipment is almost 100% made locally.

Designing Energy Plantation for Wood Pellet Production: Don't Choose the White Calliandra!

Day by day more and more parties are interested in the production of wood pellets from the energy plantation. The calliandra energy plantation is the choice of most prospective producers of wood pellets. This is because plants can grow fast and coppice has many advantages, including high woody biomass productivity, does not need to be rejuvenated every year and easy maintenance. And it turns out that the interest in making the calliandra energy plantation has also begun to spread to various regions in Indonesia and even abroad. By making energy plantations, it does have many advantages, especially in the supply of raw material will be more guaranteed and large quantities of raw materials achieved. Some of the advantages of wood pellet production from the energy plantations also can be read here. Besides calliandra, gliricidae ranks second for choice of energy plantation plant species. Even Sri Lanka will soon produce wood pellets from gliricidae, for more details, please read here.

Designing energy plantations for wood pellet production in large capacity is not a simple job. For the global scheme, you can read here. One thing to note is the selection of calliandra seeds themselves. Erroneous selection of calliandra seeds will be fatal, especially for large plantations. It turns out that there are two types of calliandra, namely red calliandra and white calliandra. Red calliandra is suitable for energy plantation and wood pellet production. Why is that? This is because there are several advantages of the species of red calliandra compared to white calliandra, namely first, the ability of coppice for red calliandra can be up to 15-20 years then rejuvenated (replanting), while white calliandra is only about 5 years old for coppice every year and must be rejuvenated. Second, red calliandra wood has a calorific value of more than 4000 kcal / kg while white calliandra is lower than 4000 kcal / kg. So when making the calliandra energy plantation is not automatic any calliandra seed can be used, but it must be selected and the red calliandra selected.

There is one more thing that is usually missed by the parties who will produce wood pellets from the energy plantation, namely optimizing the energy plantation. Of course, to optimize the growth of energy crops fertilizer is needed and if integrated with sheep, goat and cattle farms, then besides meat production it will also produce fertilizer. Though also calliandra leaves are also very good for animal feed because of its high protein content, due to the roots of the calliandra plant which is able to bind nitrogen from the atmosphere. Even if the farms developed are also large, the biogas can also be made of the manure. In addition honey bee farms can also be added, and even calliandra honey, including high-quality honey. For more details about large plantations and large farms, please read here.

Wood Waste of Replanting For Sawdust Charcoal Briquette Production

Palm Oil Trunk

Rubber Wood

At a certain age the trees on large plantations are no longer productive so they need to be replanted to maintain the sustainability of the plantation business. Two large plantation groups in Indonesia, which cover millions of hectares, are palm oil plantations and rubber plantations. Wood waste from the trunks of these trees can reach thousands or even millions of tons, and is generally not utilized. Indeed, there are uses of replanting wood waste for furniture, buildings and household appliances industries, but the portion is still very small so it cannot absorb the huge volume of wood. For example rubber wood can also be used for industrial furniture, wood and building wood, as well as palm oil logs. Even rubber wood is also used for making particle boards such as MDF (Medium Density Fibreboard) or HDF (High Density Fibreboard).

Sawdust Charcoal Briquette

Sawdust Briquette Charcoal in Carton Box

The utilization or processing of replanting wood waste for the production of wood charcoal briquette (sawdust charcoal briquette) is the right solution for this problem. Large market potential factors and product specification requirements that are not too difficult make this business attractive. In contrast to wood pellet products which are usually for power plants that require large volumes of supply and very strict specifications, so sawdust charcoal briquette products in addition to the volume of supply also do not have to be large and the specifications are more loose. This is because the use of sawdust charcoal briquette is for barbecue or more specifically mostly for roasting lamb meat in Saudi Arabia, the Middle East and Turkey. In wood pellets for electricity generation specifications are often difficult to fulfill, especially in the chemical aspects of ash such as chlorine, potassium and even sulfur, to be more clearly read here. Whereas in the production of sawdust charcoal briquette for chemical ash, the level of which is only ppm is not a problem at all.

Charcoal Briquette Production Route

Many people think that the production of sawdust briquette charcoal requires additional adhesives such as starch (tapioca), this is understandable because many people still do not know about the production process of the sawdust charcoal briquette. To produce charcoal briquettes in general, using charcoal raw material is then crushed into powder and added adhesive (such as starch) and then briquetted. The briquette product is then dried and packaged to be marketed. The production process of charcoal briquettes in this way is less good and less acceptable to the market. While the production process by means of the wood is crushed about the size of sawdust and then dried and then briquetted. The briquetting does not require adhesive because in wood there is always a lignin compound, which is useful as the adhesive. Furthermore, the briquettes are carbonized to increase fixed carbon and reduce volatile matter. Charcoal briquette products in this way, commonly called sawdust charcoal briquette, have better quality and are in demand by the market. The above scheme is enough to explain 2 routes of the production process of two types of charcoal briquettes.

Wood waste of replanting in time will also run out and be replaced by new plants. How can the sawdust charcoal briquette production business continue? A production unit certainly requires a supply of raw materials. To be able to continue to supply raw materials for production, one alternative is to make energy plantations. The energy plantations can be with fast rotation plants such as calliandra or gliricidae. To optimize woody biomass productivity and business, the energy plantation should be integrated with sheep, cattle and honey bee farms. And for more details can be read here.

Biogas, a Big Potential That is Still Not Much Glimpsed

The main purpose of processing liquid waste that is rich in organic materials is to get clean water both used again (re-use) and disposed of. Biogas products are produced mainly for processing large-capacity liquid waste. The processing stage consists of two stages namely primary and secondary processing. In primary processing, primary sludge will be produced from clarifier or settling tank. The liquid waste is passed to the clarifier or settling tank and the sludge deposit is produced. While in secondary processing, liquid waste is aerated to stimulate microbial growth. These microbes form a floc and settle into secondary sludge. The sludge or sediment must be treated at that location or transported to another place to be processed or disposed of.

The sludge processing unit usually consists of two or four stages. In sludge processing units, small capacity usually consists of only two stages, while large capacity can consist of a total of four stages. The stages of the process are: thickening, digestion (fermentation), dewatering (drying) and sterilization. In the processing unit, small capacity usually only consists of thickening and dewatering, then sludge is further processed elsewhere. Sterilization is only done when there are rules or orders to do it, so it is not done much. In large capacity processing units, the concentrated sludge is then anaerobically fermented to break down complex compounds with the help of microbes, reduce solid volatile and pathogens in the sludge, and simultaneously reduce the occurrence of foul odors.

The sludge fermentation produces biogas. Biogas production depends on sludge composition, residence time in fermentation equipment / digester, temperature and speed of microbial metabolism, which is carefully controlled. If the amount of biogas produced is only small, it is usually only flared or heated in the digester. Whereas if the amount of biogas produced is quite large, it can be used for cogeneration fuel sources. Electricity can also be produced and can be used for internal and external needs. Heat from electricity production can also be used to maintain the digester temperature so that the fermentation process can be optimal. Other options are used to produce renewable natural gas (RNG). RNG can then be used for a variety of purposes both for industry and households.

Tractor with Biogas Fuel

Potential liquid waste for biogas production is from palm oil mill effluent. As the largest CPO producer in the world, Indonesia as first rank and Malaysia second rank, both of which are estimated to have more than 1500 palm oil mills, so the potential for biogas production is also very large. The processing of wastewater from oil palm mills includes large capacity, because the average palm oil mill has a capacity of 60 tons / hour FFB and produces 700 liters of liquid waste for every ton of FFB processed. The use of biogas can be used for energy sources in the palm oil mill. There are two ways that can be done on this matter, namely biogas is used to fuel the palm oil mill with existing equipment with only a few modifications, especially on the biogas burner. In this way palm kernel shells (PKS) and mesocarp fiber commonly used in energy sources can be reduced or even utilized for others.

Whereas the second method, namely biogas output is purified so that generator fuel (gas engine generator) can be used and electricity is used for the operation of the palm oil mill, while the steam needs for sterilization of palm oil mills can remain with the palm fiber and shell or biogas that is. In addition, if the biogas can be packaged in a tube (such as a 3 kg or 12 kg LPG tube) or tank, the use can be wider. Vehicles used to support the palm oil business can use biogas as fuel. Remote communities around oil palm mills who also often find electricity supply because it is very remote can use the biogas to fuel electricity generators. Various business and industrial activities can be done with the availability of electricity. This means also encouraging economic growth of the community surrounding the palm oil mill. Of course not only economic problems are stretching and developing, but also education, religion, health, and social affairs can also develop together well.