PAO and UCO Become Bio-Jet Fuel

Decarbonization has entered all lines including the air transportation sector. Aviation fuel must also gradually shift from fossil fuels to sustainable renewable fuels. However, decarbonization in this sector is still slow, namely currently only around 0.01% of the use of sustainable renewable fuels or SAF (Sustainable Aviation Fuel) globally for these aircraft. These barriers include technological maturity or technological readiness, certification for SAF conversion or production process routes, scale up and commercialization, price gaps with fossil fuels, and competition with biofuels in the land transportation sector. The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) has initiated a reduction in GHG emissions for global aviation. Using the 2019 baseline, it is estimated that around 2.5 billion tonnes of CO2 emissions need to be offset / reduced in the 2021-2035 period to achieve carbon neutral growth. CORSIA also plans its implementation in three phases, namely the pilot phase in 2021-2023, the first phase in 2024-2026 and the second phase in 2027-2035. Participation of member countries is voluntary in the first two phases (2021-2026) and mandatory in the 2027 phase and beyond, except for the least developed countries, small developing countries and landlocked countries.

Until now, HVO / HEFA - SPK (Hydro-processed Esters and Fatty Acids-Synthesized paraffinic kerosene) technology using vegetable oil including waste oil is the only technology that is most ready for the conversion or production of SAF. Currently, the technology readiness level (TRL) and feedstock readiness level (FRL) are at level 9, meaning that it is the most ready among other conversion technology routes. One of the advantages of HVO technology is the flexibility of using various feedstocks / raw materials so that waste oil such as PAO or mico from palm oil mill ponds and also used cooking oil or used cooking oil or UCO are also very potential to be converted into SAF with HVO technology. But in fact, even though HVO technology can directly produce SAF, most of the HVO technology is used for the production of diesel engine fuel for land transportation or commonly called green diesel or renewable diesel. Green diesel or renewable diesel is different from biodiesel or FAME-based biodiesel which is produced by the transesterification process. And green diesel or renewable diesel from HVO also has a number of advantages compared to FAME based biodiesel.

HVO production is also not a new technology. Globally, there are a number of large-capacity commercial HVO plants that use vegetable oil as raw material. The largest plants are Neste in Rotterdam and Singapore with a capacity of 1.28 billion liters per year and Diamond Green Diesel in Louisiana with a capacity of 1.04 billion liters per year. HVO production is closer to petroleum refining technology than conventional diesel production. This is why oil and gas companies may be more interested in developing it than palm oil companies or conventional biodiesel companies. Palm oil mills have raw materials / feedstock, while oil and gas companies may be more relevant to downstream development because of the readiness to adapt technology and develop end products.

HVO is produced by hydrogenation and hydrocracking of vegetable oils and animal fats using hydrogen and catalysts at high temperature and pressure. In this hydrotreating process, oxygen is released from the feedstock consisting of triglycerides and / or fatty acids. This will produce straight chain hydrocarbons (paraffins) with various properties and molecular sizes depending on the characteristics of the raw materials and the operating conditions of the process being carried out. This conversion usually goes through two stages, namely hydrotreatment followed by hydrocracking / isomerization. This hydrotreatment process is usually carried out at a temperature of 300 -390 C and for triglyceride treatment, propane is usually produced as a by-product. The final product of straight chain hydrocarbons can be adjusted according to certain fuel types such as bio jet fuel or SAF. Currently HVO is the third most common biofuel in the world after ethanol and FAME based biodiesel.

PAO is produced as waste or by-product of palm oil mills. PAO will always be produced because palm oil mills cannot have an efficiency level of 100% and the less efficient the palm oil mill, the more oil becomes waste or by-product in the form of PAO. It is estimated that there are currently 1 million tons of PAO in Indonesia and 0.5 million liters in Malaysia or a total of 1.5 million tons. As for UCO or used cooking oil with the use of cooking oil reaching 1.55 million tons/year assuming 10% can be recovered as used cooking oil or UCO, 155 thousand tons/year are produced. In addition to being part of the effort to overcome waste both in palm oil mills and households that pollute the environment, the production of SAF or bio-jet fuel has also contributed to the decarbonization of the air transportation sector. With HVO / HEFA technology that is able to process waste oil such as PAO and UCO, the more PAO and UCO that can be processed, the better.

Palm Kernel Shell (PKS) Exporter Company and Developing Wood Pellet Production Business

PKS loading for export

The decarbonization trend that continues to increase along with the increasing demand for biomass fuel has made a number of palm kernel shell (PKS) exporting companies plan to expand their business into wood pellet production. Established palm kernel shell exporters usually have sales contracts with overseas buyers, which can be short-term or long-term contracts. This palm kernel shell exporters only collect palm kernel shells from a number of palm oil mills/CPO factories, then cleans them and simply dries them before they are ready to be shipped. Indeed, there are also a number of overseas buyers of palm kernel shells which do not need cleaning and drying so the price is also cheaper. Cleaning palm kernel shells usually uses a sieve (screening) machine, either a vibrating screen or a rotary screen, for more details, you can read here. Meanwhile, for drying, it is usually only aired by occasionally turning over the pile of palm kernel shells with an excavator.

Palm kernel shells and wood pellets are two popular biomass fuels in the global biomass fuel market. Palm kernel shells are the main competitor of wood pellet products because they have almost the same properties such as calorific value, ash content, size and so on, but palm kernel shells are usually cheaper because they are a by-product or waste from palm oil mills and only require a simple process to produce then exported. Meanwhile, wood pellets, although the raw material can come from woodworking industry waste or sawmills, require a more complex production process and investment in the equipment required. 

Typical Circulating Fluidized Bed (CFB) power plant in Japan

Palm kernel shells and wood pellets are mostly used as fuel for power plants abroad such as Japan and Korea. Wood pellets can be used in almost all coal power plants by cofiring, while palm kernel shells are more limited. This is mainly because crushing palm kernel shells and mixing them with coal powder (cofiring) in pulverized combustion is more difficult. Palm kernel shells can be used 100% in power plants with fluidized bed or stoker technology. And currently quite a lot of power plants in Japan use fluidized bed technology.

And because they are in the same market, palm kernel shell exporters are also very likely to know the need for wood pellets. Buyers of palm kernel shells abroad are usually also buyers of wood pellets too. The practice of collecting palm kernel shells from palm oil mills is almost the same activity as collecting wood waste from wood processing industries and sawmills, so it should not be difficult for exporters of palm kernel shells. But creating energy plantations as raw material for wood pellet production is the ideal solution. Collecting wood waste or collaborating with the wood industry that produces this waste is an intermediate solution and energy plantations are the ideal solution. Thus, it is very reasonable for palm kernel shell exporters to expand into the wood pellet production business.

EFB Pellets with Low Potassium (K) and Chlorine (Cl) for Power Plants

Palm oil mills that have excess energy, especially electrical energy, will have more freedom to develop their business. The excess electrical energy could have come from the production of electricity from the use of biogas. Liquid waste (pome) from palm oil mills is the raw material for biogas production. A palm oil mill with a production capacity of 30 tons of FFB/hour will be able to generate 1 MW of electricity and so on. One of the products that can be processed from the utilization of palm oil solid waste as well as the development of this business by utilizing excess energy is EFB pellets production. With the high price of palm kernel shells or PKS and wood pellets, the driving force or need for EFB pellets is increasing. Global awareness regarding decarbonization or CO2 removal (CDR) or CO2 reduction is the main driving force.

Apart from that, the production of EFB pellets can also be carried out by a separate company by purchasing the raw materials for EFB from palm oil mills. With conditions in Indonesia where there are still very few palm oil mills that have biogas units so that they have electricity supply and can process EFB into EFB pellets, there is still a lot of EFB that has not been utilized and becomes waste that pollutes the environment. This makes EFB pellet producing companies not have to worry about the supply of EFB raw materials. In fact, because the amount or volume of EFB is very large, the EFB pellet plant will be overwhelmed by the abundance of this raw material.

However, due to the high content of EFB in potassium and chlorine (ash chemistry), the use of EFB pellets is limited or can only be used in certain types of power plants, especially stokers and fluidized beds. In fact, most power plants currently use pulverized combustion technology. This is so that the chemical content of ash in EFB must be made as friendly as possible to boilers, especially those with pulverized combustion technology. This can be done so that the chemical content of the ash in the form of potassium (K) and chlorine (Cl) is only less than 2000 ppm. Potassium (K) with a low melting point causes deposits or scale to form in the heat exchanger pipes in the boiler so that the efficiency of heat exchange decreases while chlorine (Cl) is corrosive which shortens the life of the equipment. The treatment was even successful in reducing K and Cl by up to 80% so that the problem of fouling thickness and corrosivity was also reduced by 80%. With the number of palm oil mills in Indonesia reaching around 1000 units, of course the amount of EFB that can be processed into EFB pellets is also very large.

The Importance of SRF (Slow Release Fertilizer) With Biochar in Palm Oil Plantations

Biochar is not a fertilizer so even the nutrient content in biochar can be ignored. Even though there are a number of biochars that contain certain nutrients, this is a special matter and really depends on the raw materials used. Biochar is a soil amendment that functions to improve soil properties such as soil structure including increasing soil porosity/soil friability so that roots can penetrate deeper, soil aeration, water availability, shortening the age of harvest, inhibiting the development of plant pests and retaining nutrients and reducing soil acidity. Compared to other soil amendments which have weaknesses, including the need for large and continuous amounts because they decompose quickly, have the potential to negatively affect the climate, and introduce disease-causing microbes/pests, biochar has many advantages, including the volume required is not large enough, not continuous and able to survive in the soil (helps conserve carbon in the soil) is not decomposed for hundreds or even thousands of years. The above makes biochar can function to improve soil fertility and climate solutions (carbon sequestration / carbon sink) or an action to increase organic matter on agricultural land or plantations and mitigate the effects of climate change. 

Even so, biochar can be used to make fertilizer, namely slow release fertilizer (SRF). SRF is a fertilizer whose release is regulated to provide maximum growth effect or SRF is designed or modified fertilizer for controlled fertilization according to plant needs so as to provide increased use efficiency and at the same time increase yield or harvest. This is motivated by the low efficiency of fertilization so that even more is wasted than is utilized or low NUE (nutrient use efficiency). The function of biochar in SRF is as a slow release agent in the fertilizer because it has a porous structure. In making SRF, several methods can be used, including increasing the size (granulation, pellets, etc.), smoothing the surface of the fertilizer, mixing it with other materials that are difficult to dissolve (slow-release agent) and covering the fertilizer with certain materials so that the release of the fertilizer becomes slow (coating). The use of SRF is becoming popular to save fertilizer consumption, increase yields and minimize environmental pollution. 

Soil fertility is a complex trait or condition that must be kept optimal, especially regarding this fertilization. The component of soil fertility itself includes a number of things, namely the depth of the soil solum, soil structure, nutrient content, storage capacity, humus content, number and activity of soil microorganisms, and the content of toxic elements. Productive soils with high soil fertility, both naturally and/or due to human actions, are mainly due to the following characteristics: nutrients in the soil are mobile and easy to obtain, the ability of the soil to convert fertilizer into easily available forms, the ability of the soil to store nutrients dissolved in groundwater from the leaching process, the ability of the soil to provide a natural balance of nutrient supplies for plants, the ability of the soil to store and provide water for plants, the ability to maintain good soil aeration to ensure the availability of oxygen for roots, and the ability of the soil to bind (fix) nutrients and convert them into forms available to plants. Soil fertility must guarantee high, consistent and sustainable production.  

An understanding of the nutrient composition of fertilizer and its release mechanism will help make strategic plans to slow down the release of the fertilizer at a certain level. Compared to conventional fertilizers slow release fertilizer (SRF) has a very slow release speed which can be tens of times slower so that fertilization efficiency increases significantly. It is estimated that more than 50% of fertilizer is wasted due to various reasons including evaporation, immobilization in the soil and leaching due to water, for example due to rain or irrigation. This inefficiency of fertilization is not only detrimental from an economic aspect as well as the environment, namely making the soil acidic, killing soil microbes, and water-soluble fertilizers that can poison water that may be consumed by humans and animals.

Currently, developing countries use more than 60 million tons of fertilizer per year, while according to the Food Agriculture Organization (FAO) world fertilizer consumption reached 190.4 million tons in 2015. With this low level of efficiency, can be imagined how much fertilizer is wasted useless and only pollute the environment. Regarding SRF, the dose of biochar use must also be measured properly because the use of biochar that exceeds the dose will be useless. This is due to the hydrophobic nature of biochar, so that the excess dose does not or only a little can release the fertilizer slowly.

A number of parameters to be observed for administering biochar as SRF are the amount of FFB (fresh fruit bunch) production and its quality (yield of CPO, and its FFA content), continuity of fruiting throughout the year, and the level of uniformity of fruit maturity in one bunch. And it turns out that the use of biochar gave significant positive results, namely FFB production increased by more than 20%, fruit maturity uniformity was almost 100%, CPO yield was more than 25%, and FFA was only 2-5%. With the high production of FFB and the yield of CPO, the intensification of palm oil plantations should have been carried out rather than the extensification that was suspected of being an attempt to convert forest functions or deforestation which tends to receive negative attention from various parties. For more details, read here. There are still many things that can be optimized so that the palm oil industry is efficient, environmentally friendly and sustainable.

Tens of millions of tons of empty fruit bunches (EFB) at the palm oil mills are potential raw material for biochar production as well as tens of millions of hectares of oil palm plantations that can be used for biochar applications. In addition to overcoming the problem of biomass waste, biochar production also produces energy that can be used for the palm oil mill itself, in more detail, please read here. Compared to the production of fuel pellets from empty fruit bunches (EFB pellets) and the production of electricity from empty fruit bunches, the production of biochar has many advantages and advantages both economically and environmentally. In the end, modifying the fertilizer according to the use of the biochar will significantly increase the nutrient use efficiency (NUE) in the fertilizer, ensuring the effective circulation of nutrients and mitigating climate change with carbon sequestration.
 

Palm Oil Mill Redesign for IVO Production: Using Pyrolysis, Gasification or Biogas?

The production of biodiesel / green diesel using raw material of RBD PO is too good (overspec) and too expensive, so it needs to be replaced with a cheaper raw material, namely IVO (industrial vegetable oil). For this purpose, it is necessary to redesign the palm oil mill so that a number of FFB extraction production into CPO carried out at the palm oil mill need to modify the process flow. The sterilization process can be eliminated so that there is no need for water for steam production as well as boilers and steam turbines for electricity production. Water treatment units may also be no longer needed or may still be needed but for different processes.

Another important thing is the supply of energy, especially electricity, for this new type of palm oil mill. This is because most of the equipments used in the palm oil mill are mechanical equipments that work by consuming electricity. As the mill that has a lot of biomass waste, it's certainly not a difficult thing to do, even so far, palm oil mills produce their own electricity by burning palm mesocarp fiber and palm kernel shell in the boiler. But in a new type of palm oil mill with a different configuration, the boiler may not be needed or it is still needed but there are differences from before. Basically, of course, how to achieve the highest level of efficiency with the new process.

Another factor is how the new production process also provides greater benefits for the palm oil industry, for example biochar products are also produced. The biochar product will later be used in palm oil plantations to improve soil fertility and also as a carbon sink and absorb N2O gas, which is a greenhouse gas. Carbon credits from the application of biochar as a carbon sink will also provide additional income for the palm oil industry, which is also not a small amount. Currently, many palm oil plantations are located on acid soils or with low pH, which results in low productivity of palm oil yield, so it needs to be increased. Also, in the operation of palm oil plantations, the cost of fertilizer is the highest cost component, and for this reason, biochar is the solution to this problem. With the high productivity of FFB with this treatment, the clearing of palm oil land is no longer needed, so that the focus on palm oil plantations which causes deforestation is also reduced, more info read here.

For electricity production, apart from burning palm nesocarp fiber and palm kernel shell in the boiler, then the resulting steam drives a steam turbine, another way is pyrolysis and gasification of biomass. With pyrolysis (slow pyrolysis) more biochar production or as the main product. Whereas with gasification the product of biochar is less with more main gas product. Biogas from liquid waste (POME) is another energy source that can be used. Basically it depends on the goals and needs, how much electricity is needed, how much biochar is needed and so on. But with the area of palm oil plantations reaching tens of thousands of hectares, the need for biochar will be very large, so pyrolysis will be more suitable to be applied. And if the demand for electricity is large enough, then electricity from biogas can also be used as an addition to electricity from pyrolysis. 

Even with this pyrolysis, other useful products for palm oil plantations will also be produced, such as liquid smoke. This liquid smoke can be used as a biopesticide whose application can use agricultural drones at speeds of 16 hectares/hour or more. Biooil products from pyrolysis can also be used for direct fuel using a burner or further refined to become vehicle fuel. Burning gas or liquid fuels will give cleaner emissions to palm oil mills compared to burning solid fuel that has been done so far.

Digestate from biogas can be used together with biochar so that it can provide maximum results in palm oil plantations. With a porous biochar structure, digestate plus biochar will become a slow release organic fertilizer so that fertilizer use will be more efficient. Apart from that, with the large amount of potential for biomass waste in the palm oil industry, it also allows for a number of business developments, especially if there is an adequate supply of energy. An example is the production of activated carbon from palm kernel shells (PKS) or the processing of kernels into kernel oil (crude palm kernel oil). By optimizing all the potential, especially biomass waste so that it can provide economic and environmental benefits, the palm oil industry will be even more attractive.