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

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

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

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

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

  

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

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

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

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

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

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