Palm Kernel Shells

Palm Kernel Shell is generating very good traction as a renewable energy resource and biomass commodity in Japan. This is because PKS is the cheapest biomass fuel and is available in large quantities across Southeast Asia. PKS, a biomass waste generated by palm oil mills, can be found in plentiful quantities in Indonesia, Malaysia and Thailand.

PKS must meet the specifications before being exported to Japan. Some key specifications for PKS exports are: moisture content, calorific value and impurities or contaminants (foreign materials). All three variables must meet a certain level to achieve export quality. Japanese markets or their consumers generally require contaminants from 0.5 to 2%, while European consumers of PKS need 2% – 3%.

Japan usually buys with a volume of 10,000 tonnes per shipment, so PKS suppliers must prepare a sufficient stockpile of the PKS. The location of PKS stockpile that is closest to the seaport is the ideal condition to facilitate transportation of shipment.

Wood Pellets

Wood pellets are mostly produced in from wood waste such as sawdust, wood shaving, plywood waste, forestry residues, and related materials while using tools like track saws, table saws, circular saws, miter saws, etc. The development potential for quantity enlargement is also possible with energy plantations. Technically the properties of wood pellets are not much different from the PKS.

Wood pellet price is more expensive than PKS. Wood pellet production process is more complex than PKS, so wood pellet is categorized as finished product. The quality of wood pellet is generally viewed from its density, calorific value and ash content. Indonesia wood pellet export is not as big as PKS, it is also because of the limited producers of wood pellet itself.

Japan buys wood pellets from Indonesia mostly for testing on their biomass power plants. Shipping or export by container is still common in wood pellet sector because the volume is still small. Currently, the world’s leading producer of wood pellets come from North America and Scandinavia. Even for Indonesia itself wood pellet is a new thing, so its production capacity is also not big.

Future Perspectives

For a short-term solution, exporting PKS is a profitable business. Wood pellets with raw materials from energy plantations by planting the legume types such as calliandra are medium-term solutions to meet biomass fuel needs in Japan. Torrefaction followed by densification can be a long-term orientation. Torrified pellet is superior to wood pellet because it can save transportation and facilitate handling, are hydrophobic and has higher calorific value.

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With relatively low operating temperature of around 650 – 900 ^oC, the ash problem can be minimized. Certain biomass fuels have high ash levels and ash-forming materials that can potentially damage these generating units.

In addition, the fuel cleanliness factor is also important as certain impurities, such as metals, can block the air pores on the perforated plate of FBC unit. It is to be noted that air, especially oxygen, is essential for the biomass combustion process and for keeping the fuel bed in fluidized condition.

The requirements for clean fuel must be met by the provider or seller of the biomass fuel. Usually the purchasers require an acceptable amount of impurities (contaminants) of less than 1%. Cleaning of PKS is done by sifting (screening) which may either be manual or mechanical.

In addition to PKS, biomass pellets from agricultural wastes or agro-industrial wastes, such as EFB pellets which have a high ash content and low melting point, can also be used in CFB-based power plants. More specifically, CFBs are more efficient and emit less flue gas than BFBs.

The disadvantages of CFB power plant is the high concentration of the flue gas which demands high degree of efficiency of the dust precipitator and the boiler cleaning system. In addition, the bed material is lost alongwith ash and has to be replenished regularly.

The commonly used bed materials are silica sand and dolomite. To reduce operating costs, bed material is usually reused after separation of ash. The technique is that the ash mixture is separated from a large size material with fine particles and silica sand in a water classifier. Next the fine material is returned to the bed.

Currently power plants in Japan that have an efficiency of more than 41% are only based on ultra supercritical pulverized coal. Modification of power plants can also be done to improve the efficiency, which require more investments. The existing CFB power plants are driving up the need to use more and more PKS in Japan for biomass power generation without significant plant modifications.

The post Use of PKS in Circulating Fluidized Bed Power Plants first appeared on BioEnergy Consult.

Palm kernel shells (or PKS) are the shell fractions left after the nut has been removed after crushing in the palm oil mill. Palm kernel shells are a fibrous material and can be easily handled in bulk directly from the product line to the end use. Large and small shell fractions are mixed with dust-like fractions and small fibres.

Moisture content in kernel shells is low compared to other biomass residues with different sources suggesting values between 11% and 13%. Palm kernel shells contain residues of Palm Oil, which accounts for its slightly higher heating value than average lignocellulosic biomass. Compared to other residues from the industry, palm kernel shells are a good quality biomass fuel with uniform size distribution, easy handling, easy crushing, and limited biological activity due to low moisture content.

Press fibre and kernel shell generated by the palm oil mills are traditionally used as solid fuels for steam boilers. The steam generated is used to run turbines for electricity production. These two solid fuels alone are able to generate more than enough energy to meet the energy demands of a palm oil mill.

Most palm oil mills in the region are self-sufficient in terms of energy by making use of kernel shells and mesocarp fibers in cogeneration. The demand for palm kernel shells has increased considerably in Malaysia, Indonesia and Thailand resulting in price close to that of coal. Nowadays, cement industries are using palm kernel shells to replace coal mainly because of CDM benefits.

PKS has also emerged as a hot biomass commodity in the Asia-Pacific region, especially in South Korea and Japan, where PKS is being used to power huge biomass power plants. PKS is also getting traction in Europe as an attractive alternative fuel.

The problems associated with the burning of these solid fuels are the emissions of dark smoke and the carry-over of partially carbonized fibrous particulates due to incomplete combustion of the fuels can be tackled by commercially-proven technologies in the form of high-pressure boilers.

Dual-fired boilers capable of burning either diesel oil or natural gas are the most suitable for burning palm Oil waste since they could also facilitate the use of POME-derived biogas as a supplementary fuel. However, there is a great scope for introduction of high-efficiency CHP systems in the industry which will result in substantial supply of excess power to the public grid.

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Major Applications

Nowadays, the primary use of palm kernel shells is as a boiler fuel supplementing the fibre which is used as primary fuel. In recent years kernel shells are extensively sold as alternative fuel around the world. Besides selling shells in bulk, there are companies that produce fuel briquettes from shells which may include partial carbonisation of the material to improve the combustion characteristics.

Palm kernel shells have a high dry matter content (>80% dry matter). Therefore the shells are generally considered a good fuel for the boilers as it generates low ash amounts and the low K and Cl content will lead to less ash agglomeration. These properties are also ideal for production of biomass for export.

As a raw material for fuel briquettes, palm shells are reported to have the same calorific characteristics as coconut shells. The relatively smaller size makes it easier to carbonise for mass production, and its resulting palm shell charcoal can be pressed into a heat efficient biomass briquette.

Although the literature on using oil palm shells (and fibres) is not as extensive as EFB, common research directions of using shells, besides energy, are to use it as raw material for light-weight concrete, fillers, activated carbon, and other materials. However, none of the applications are currently done on a large-scale. Since shells are dry and suitable for thermal conversion, technologies that further improve the combustion characteristics and increase the energy density, such as torrefaction, could be relevant for oil palm shells.

Torrefaction is a pretreatment process which serves to improve the properties of biomass in relation to the thermochemical conversion technologies for more efficient energy generation. High lignin content for shells affects torrefaction characteristics positively (as the material is not easily degraded compared to EFB and fibres).

Furthermore, palm oil shells are studied as feedstock for fast pyrolysis. To what extent shells are a source of fermentable sugars is still not known, however the high lignin content in palm kernel shells indicates that shells are less suitable as raw material for fermentation.

Future Outlook

The leading palm oil producers in the world should consider limiting the export of palm kernel shells (PKS) to ensure supplies of the biomass material for renewable energy projects, in order to decrease dependency on fossil fuels. For example, many developers in Indonesia have expressed an interest in building palm kernel shell-fired power plants.

However, they have their concerns over supplies, as many producers prefer to sell their shells overseas currently. Many existing plants are facing problems on account of inconsistent fuel quality and increasing competition from overseas PKS buyers. PKS market is well-established in provinces like Sumatra and export volumes to Europe and North Asia as a primary fuel for biomass power plants is steadily increasing.

The creation of a biomass supply chain in palm oil producing countries may be instrumental in discouraging palm mills to sell their PKS stocks to brokers for export to foreign countries. Establishment of a biomass exchange in leading countries, like Indonesia, Malaysia and Nigeria, will also be a deciding factor in tapping the unharnessed potential of palm kernel shells as biomass resource.

The post Trends in Utilization of Palm Kernel Shells first appeared on BioEnergy Consult.

In a typical palm oil mill, almost 70% of the fresh fruit bunches are turned into wastes in the form of empty fruit bunches, fibers and shells, as well as liquid effluent. These by-products can be converted to value-added products or energy to generate additional profit for the Palm Oil Industry.

Palm Kernel Shells (PKS)

Palm kernel shells (or PKS) are the shell fractions left after the nut has been removed after crushing in the Palm Oil mill. Kernel shells are a fibrous material and can be easily handled in bulk directly from the product line to the end use. Large and small shell fractions are mixed with dust-like fractions and small fibres.

Moisture content in kernel shells is low compared to other biomass residues with different sources suggesting values between 11% and 13%. Palm kernel shells contain residues of Palm Oil, which accounts for its slightly higher heating value than average lignocellulosic biomass. Compared to other residues from the industry, it is a good quality biomass fuel with uniform size distribution, easy handling, easy crushing, and limited biological activity due to low moisture content.

Press fibre and shell generated by the Palm Oil mills are traditionally used as solid fuels for steam boilers. The steam generated is used to run turbines for electricity production. These two solid fuels alone are able to generate more than enough energy to meet the energy demands of a Palm Oil mill.

Empty Fruit Bunches (EFBs)

In a typical Palm Oil mill, empty fruit bunches are abundantly available as fibrous material of purely biological origin. EFB contains neither chemical nor mineral additives, and depending on proper handling operations at the mill, it is free from foreign elements such as gravel, nails, wood residues, waste etc. However, it is saturated with water due to the biological growth combined with the steam sterilization at the mill. Since the moisture content in EFB is around 67%, pre-processing is necessary before EFB can be considered as a good fuel.

In contrast to shells and fibers, empty fruit bunches are usually burnt causing air pollution or returned to the plantations as mulch. Empty fruit bunches can be conveniently collected and are available for exploitation in all Palm Oil mills. Since shells and fibres are easy-to-handle, high quality fuels compared to EFB, it will be advantageous to utilize EFB for on-site energy demand while making shells and fibres available for off-site utilization which may bring more revenues as compared to burning on-site.

Palm Oil Mill Effluent (POME)

Palm Oil processing also gives rise to highly polluting waste-water, known as Palm Oil Mill Effluent, which is often discarded in disposal ponds, resulting in the leaching of contaminants that pollute the groundwater and soil, and in the release of methane gas into the atmosphere. POME could be used for biogas production through anaerobic digestion. At many palm oil mills this process is already in place to meet water quality standards for industrial effluent. The gas, however, is flared off.

In a conventional Palm Oil mill, 600-700 kg of POME is generated for every ton of processed FFB. Anaerobic digestion is widely adopted in the industry as a primary treatment for POME. Liquid effluents from palm oil mills can be anaerobically converted into biogas which in turn can be used to generate power through gas turbines or gas-fired engines.

Conclusions

Most of the Biomass residues from Palm Oil Mills are either burnt in the open or disposed off in waste ponds. The Palm Oil industry, therefore, contributes significantly to global climate change by emitting carbon dioxide and methane. Like sugar mills, Palm Oil mills have traditionally been designed to cover their own energy needs (process heat and electricity) by utilizing low pressure boilers and back pressure turbo-generators. Efficient energy conversion technologies, especially thermal systems for crop residues, that can utilize all Palm Oil residues, including EFBs, are currently available.

In the Palm Oil value chain there is an overall surplus of by-products and their utilization rate is negligible, especially in the case of POME and EFBs. For other mill by-products the efficiency of the application can be increased. Presently, shells and fibers are used for in-house energy generation in mills but empty fruit bunches is either used for mulching or dumped recklessly. Palm Oil industry has the potential of generating large amounts of electricity for captive consumption as well as export of surplus power to the public grid.

The post Biomass Wastes from Palm Oil Mills first appeared on BioEnergy Consult.

Europe is the largest producer of wood pellets, which is currently estimated at 13.5 million tons per year while its consumption is 18.8 million tons per year. The biggest wood pellet producing countries in Europe are Germany and Sweden. Europe relies on America and Canada to meet its wood pellet requirements and there is an urgent need to explore alternative biomass resources. In recent years, palm kernel shells (popularly known as PKS) from Southeast Asia and Africa has emerged as an attractive biomass resources which can replace wood pellets in biomass power plants across Europe.

What are Palm Kernel Shells

Palm kernel shells are the shell fractions left after the nut has been removed after crushing in the Palm Oil Mill. Kernel shells are a fibrous material and can be easily handled in bulk directly from the product line to the end use. Large and small shell fractions are mixed with dust-like fractions and small fibres.

Moisture content in kernel shells is low compared to other biomass residues with different sources suggesting values between 11% and 13%. Palm kernel shells contain residues of Palm Oil, which accounts for its slightly higher heating value than average lignocellulosic biomass. Compared to other residues from the industry, it is a good quality biomass fuel with uniform size distribution, easy handling, easy crushing, and limited biological activity due to low moisture content.

Press fibre and shell generated by the palm oil mills are traditionally used as solid fuels for steam boilers. The steam generated is used to run turbines for electricity production. These two solid fuels alone are able to generate more than enough energy to meet the energy demands of a palm oil mill.

Advantages of Palm Kernel Shells

PKS has almost the same combustion characteristics as wood pellets, abundantly available are and are cheap. Indonesia and Malaysia are the two main producers of PKS. Indonesian oil palm plantations cover 12 million hectares in Indonesia and 5 million hectares in Malaysia, the number of PKS produced from both countries has exceeded 15 million tons per year. Infact, the quantity of PKS generated in both countries exceeds the production of wood pellets from the United States and Canada, or the two largest producers of wood pellets today.

Interestingly, United States and Canada cannot produce PKS, because they do not have oil palm plantations, but Indonesia and Malaysia can also produce wood pellets because they have large forests. The production of wood pellets in Indonesia and Malaysia is still small today, which is less than 1 million tons per year, but the production of PKS is much higher which can power biomass power plants across Europe and protect forests which are being cut down to produce wood pellets in North America and other parts of the world.

PKS as a Boiler Fuel

Although most power plants currently use pulverized coal boiler technology which reaches around 50% of the world’s electricity generation, the use of grate combustion boiler technology and fluidized bed boilers is also increasing. Pulverized coal boiler is mainly used for very large capacity plants (> 100 MW), while for ordinary medium capacity uses fluidized bed technology (between 20-100 MW) and for smaller capacity with combustor grate (<20 MW). The advantage of boiler combustion and fluidized bed technology is fuel flexibility including tolerance to particle size.

When the pulverized coal boiler requires a small particle size (1-2 cm) like sawdust so that it can be atomized on the pulverizer nozzle, the combustor grate and fluidized bed the particle size of gravel (max. 8 cm) can be accepted. Based on these conditions, palm kernel shells has a great opportunity to be used as a boiler fuel in large-scale power plants.

Use of PKS in pulverized coal boiler

There are several things that need to be considered for the use of PKS in pulverized coal boilers. The first thing that can be done is to reduce PKS particle size to a maximum of 2 cm so that it can be atomized in a pulverized system. The second thing to note is the percentage of PKS in coal, or the term cofiring. Unlike a grate and a fluidized bed combustion that can be flexible with various types of fuel, pulverized coal boilers use coal only. There are specific things that distinguish biomass and coal fuels, namely ash content and ash chemistry, both of which greatly influence the combustion characteristics in the pulverized system.

Coal ash content is generally greater than biomass, and coal ash chemistry is very different from biomass ash chemistry. Biomass ash has lower inorganic content than coal, but the alkali content in biomass can change the properties of coal ash, especially aluminosilicate ash.

Biomass cofiring with coal in small portions for example 3-5% does not require modification of the pulverized coal power plant. For example, Shinci in Japan with a capacity of 2 x 1,000 MW of supercritical pulverized fuel with 3% cofiring requires 16,000 tons per year of biomass and no modification. Similarly, Korea Southeast Power (KOSEP) 5,000 MW with 5% cofiring requires 600,000 tons per year of biomass without modification.

PKS cofiring in coal-based power plants

Pulverized coal-based power plants are the predominant method of large-scale electricity production worldwide including Europe. If pulverised fuel power plants make a switch to co-firing of biomass fuels, it will make a huge impact on reducing coal usage, reducing carbon emissions and making a transition to renewable energy. Additionally, the cheapest and most effective way for big coal-based power plants to enter renewable energy sector is biomass cofiring. Palm kernel shells can be pyrolyzed to produce charcoal while coal will produce coke if it is pyrolyzed. Charcoal can be used for fuel, briquette production and activated charcoal.

The post Palm Kernel Shells: An Attractive Biomass Fuel for Europe first appeared on BioEnergy Consult.

Canada and USA are the biggest suppliers of wood pellets to the Japanese biomass market while PKS mainly comes from Indonesia and Malaysia. With the size of the material almost the same as wood pellets, but at a cheaper price (almost half the wood pellets) and also available in abundance, PKS is the preferred biomass fuel for the Japanese market. PKS can be used 100% in power plants that use fluidized bed combustion technology, while wood pellets are used in pulverized combustion.

Although there is abundant PKS in CPO (crude palm oil) producing countries, but fluctuations in CPO production and increase in domestic demand has led to reduction in PKS exports in Southeast Asia. In palm oil plantations, it is known as the low crop season and peak crop season. When the low crop season usually occurs in the summer or dry season, the supply of fruit to the palm oil mills decreases so that the CPO production decreases and also the supply of PKS automatically reduces, and vice versa in the peak crop season. When demand is high or even stable but supply decreases, the price of PKS tends to rise.

In addition, a wide range of industries in Indonesia and Malaysia have also began to use PKS as an alternative fuel triggering increased domestic demand. In recent years, PKS is also being processed into solid biomass commodities such as torrified PKS, PKS charcoal and PKS activated carbon. Thus, there is very limited scope of increasing PKS supply from Southeast Asia to large-scale biomass consumers like Japan and South Korea.

Palm oil mills process palm oil fruit from palm oil plantations, so the more fruit is processed the greater the PKS produced and also more processors or mills are needed. At present it is estimated that there are more than 1500 palm oil mills in Indonesia and Malaysia. Palm kernel shells from Indonesia and Malaysia is either being exported or used domestically by various industries. On the other hand, in other parts of the world PKS is still considered a waste which tends to pollute the environment and has no economic value.

West African countries, such Nigeria, Ghana and Togo, are still struggling to find a sustainable business model for utilization of PKS. Keeping in view the tremendous PKS requirements in the Asia-Pacific region, major PKS producers in Africa have an attractive business opportunity to export this much-sought after biomass commodity to the Japan, South Korea and even Europe.

Simply speaking, PKS collected from palm oil mills is dried, cleaned and shipped to the destination country. PKS users have special specifications related to the quality of the biomass fuel used, so PKS needs to be processed before exporting.

PKS exports from Indonesia and Malaysia to Japan are usually  with volume 10 thousand tons / shipment by bulk ship. The greater the volume of the ship or the more cargo the PKS are exported, the transportation costs will generally be cheaper. African countries are located quite far from the Asia-Pacific region may use larger vessels such as the Panamax vessel to export their PKS.

The post PKS From Africa Can Fuel Biomass Power Plants in Japan first appeared on BioEnergy Consult.

Palm kernel shells contain residues of Palm Oil, which accounts for its slightly higher heating value than average lignocellulosic biomass. Compared to other residues from the industry, it is a good quality biomass fuel with uniform size distribution, easy handling, easy crushing, and limited biological activity due to low moisture content. PKS can be readily co-fired with coal in grate fired -and fluidized bed boilers as well as cement kilns in order to diversify the fuel mix.

The primary use of palm kernel shells is as a boiler fuel supplementing the fibre which is used as primary fuel. In recent years kernel shells are sold as alternative fuel around the world. Besides selling shells in bulk, there are companies that produce fuel briquettes from shells which may include partial carbonisation of the material to improve the combustion characteristics.

As a raw material for fuel briquettes, palm shells are reported to have the same calorific characteristics as coconut shells. The relatively smaller size makes it easier to carbonise for mass production, and its resulting palm shell charcoal can be pressed into a heat efficient biomass briquette.

Palm kernel shells have been traditionally used as solid fuels for steam boilers in palm oil mills across Southeast Asia. The steam generated is used to run turbines for electricity production. These two solid fuels alone are able to generate more than enough energy to meet the energy demands of a palm oil mill. Most palm oil mills in the region are self-sufficient in terms of energy by making use of kernel shells and mesocarp fibers in cogeneration.

In recent years, the demand for palm kernel shells has increased considerably in Europe, Asia-Pacific, China etc. resulting in price close to that of coal. Nowadays, cement industries and power producers are increasingly using palm kernel shells to replace coal. In grate-fired boiler systems, fluidized-bed boiler systems and cement kilns, palm kernel shells are an excellent fuel.

Cofiring of PKS yields added value for power plants and cement kilns, because the fuel significantly reduces carbon emissions – this added value can be expressed in the form of renewable energy certificates, carbon credits, etc. However, there is a great scope for introduction of high-efficiency cogeneration systems in the industry which will result in substantial supply of excess power to the public grid and supply of surplus PKS to other nations. Palm kernel shell is already extensively in demand domestically by local industries for meeting process heating requirements, thus creating supply shortages in the market.

Palm oil mills around the world may seize an opportunity to supply electricity for its surrounding plantation areas using palm kernel shells, empty fruit branches and palm oil mill effluent which have not been fully exploited yet. This new business will be beneficial for all parties, increase the profitability and sustainability for palm oil industry, reduce greenhouse gas emissions and increase the electrification ratio in surrounding plantation regions.

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