Production in a palm oil mill begins with the process of extracting oil from fresh fruit bunches (FFB). This process produces various types of waste, both liquid and solid, which require management to reduce negative impacts on the environment. One of the main liquid wastes produced is POME (Palm Oil Mill Effluent), which can be processed into biogas through a biogas processing system.

For example, a palm oil mill with a production capacity of 60 tons of FFB per hour can produce around 4,000-6,000 Nm³ of biogas per day. This is due to the high organic content in POME which makes it an effective source of biogas fuel. In addition, other waste produced by palm oil mills such as empty fruit bunches, shells, and fibers can also be further processed to produce biogas or used as other renewable energy sources. Therefore, the processing of this waste, including the conversion of POME into biogas, is an important step in utilizing liquid waste into high-potential fuel.

POME is a liquid waste produced from the palm oil processing process. In general, POME has a very high organic content, including fatty acids, oils, and suspended solids. This high organic content, especially significant COD and BOD values, makes POME very dangerous if not managed properly. Thus, high COD and BOD reflect the large amount of oxygen needed to decompose organic matter in water, which can cause a decrease in dissolved oxygen in water bodies if POME is discharged without treatment. This can result in the death of aquatic organisms and damage the aquatic ecosystem.

Therefore, POME is an ideal material for biogas plants for several main reasons:

• High Organic Content: POME has a COD (Chemical Oxygen Demand) value of around 50,000 – 80,000 mg/L and a BOD (Biochemical Oxygen Demand) of around 25,000 – 35,000 mg/L, making it very suitable for biogas treatment systems. The high organic content is the main ingredient used in making biogas through anaerobic processes in biogas reactors such as biogas digesters.
• Large and Consistent Volume: Every ton of fresh fruit bunches (FFB) processed can produce around 0.5-1.2 tons of POME. Because the abundant availability of POME supports biogas waste management on a large scale, it allows biogas plants to operate sustainably and efficiently.
• Efficiency in Reducing Environmental Impacts: Processing POME in biogas plants not only produces renewable energy but also reduces environmental impacts significantly. POME, if not processed, can pollute the environment.
• Favorable Composition for Anaerobic Processes: POME has a pH and temperature that are close to optimal for the biogas production process in biogas digesters. Its nutritional content supports the growth of microorganisms needed for biogas monitoring and biogas production.

Biogas Utilization from POME: Environmental and Economic Solution

Biogas is the most ideal solution for processing POME (Palm Oil Mill Effluent) because it not only offers energy efficiency by producing biogas that can be used as an alternative energy source, but also provides significant environmental benefits. In addition, from a commercial perspective, although the initial investment costs are quite high, biogas can be a profitable long-term income. Furthermore, the results of biogas and its residues, such as organic fertilizer and biochar, offer additional income opportunities and added value, making it a sustainable and profitable investment in the long term.

Organics Bali has the expertise and advanced technology in utilizing the potential of POME for biogas production. With high-reliability European technology standards, we ensure that our biogas plants operate efficiently and smoothly after the commissioning process. We have installed and operated four active biogas plants in Indonesia, including in Sumatra and Kalimantan. Click the following link to view our portfolio and find out how we can help you optimize the potential of POME into profitable biogas.

However, special testing is needed to determine the effectiveness and quality of the biochar produced. Organics Bali has a laboratory in Bandung equipped with special equipment to conduct this testing. Furthermore, we use reference standards from the World Biochar Certificate (WBC) and Carbon Standards International to ensure that the biochar quality parameters are met.

Biomass pyrolysis is a thermochemical process that breaks down organic matter at high temperatures without oxygen. One of the products of the pyrolysis process is biochar. Biochar has various benefits, one of which is its contribution to carbon sequestration or carbon absorption.

The results of the biomass pyrolysis process include:

• Biochar: A solid product rich in carbon, useful as a soil ameliorant, pollutant absorber, and fuel.
• Biogas: A mixture of gases, mainly methane (CH₄) and carbon dioxide (CO₂), that can be used as a renewable energy source.
• Pyrolysis Oil: A complex liquid consisting of various organic compounds, including phenols, organic acids, and ketones. This oil can be used as fuel or further processed into chemicals.
• Flying Gas: Other light gases such as hydrogen (H₂), carbon monoxide (CO), and methane (CH₄) that can also be used as fuel.

The results of pyrolysis vary depending on the type of biomass, pyrolysis temperature, and process conditions.

Why Biochar is an Ideal Solution for Biomass:

Biochar is an ideal solution for biomass for several key reasons:

• Effective Carbon Storage: Plant photosynthesis absorbs CO₂ from the atmosphere and stores it in biomass. When plants die or are cut down, this carbon is released back into the atmosphere as CO₂. Sustainable biomass management aims to prevent this carbon release.
• Pyrolysis as a Solution: Pyrolysis is an ancient technique that has been used for over three thousand years to address the problem of carbon release. Specifically, the process involves heating biomass in an oxygen-free environment, producing a stable product.
• Biochar Production: During pyrolysis, biomass is converted into biochar, a stable form of carbon that can be used as a soil ameliorant. Thus, biochar helps improve soil health and reduce greenhouse gas emissions.
• Carbon Sequestration Method: Biochar functions as a carbon sequestration method, storing carbon in a form that is not easily broken down and preventing it from returning to the atmosphere as CO₂.
• Carbon Credits: The use of biochar in agriculture can be categorized as an emission reduction project that has the potential to earn carbon credits, especially in voluntary carbon market schemes. For example, the potential of biochar as part of the climate solution in Indonesia is recognized and supported by the Indonesian government, as stated in the Regulation of the Minister of Environment and Forestry Number 7 of 2023 concerning Procedures for Carbon Trading in the Forestry Sector.

By using biochar, biomass is not only managed sustainably but also makes a positive contribution to the environment and economy through emission reduction and carbon credit trading.

Biogas feedtrain refers to the system or process used to manage and feed feedstock into an anaerobic digestion system for biogas production. It includes several important stages in the processing of the feedstock before it enters the anaerobic digestion reactor. The following are the main components of a biogas feedtrain:

1. Biogas Plant

The biogas plant is the initial component that includes the collection and digestion of organic matter to produce biogas. It consists of an Anaerobic Digester (AD), where anaerobic digestion occurs in the absence of oxygen, and a Continuous Stirred-Tank Reactor (CSTR).

• Anaerobic Digester (AD): The biogas reactor where the anaerobic fermentation process occurs to produce biogas. The biogas digester is an essential component that enables the production of biogas from organic waste.
• Continuous Stirred-Tank Reactor (CSTR): The ideal biogas digester component for POME treatment as it allows for uniform mixing and efficient gas separation.

Anaerobic Digester (AD) is the most ideal component for palm oil mills because it is able to handle large volumes of POME and produce biogas with high efficiency. In addition, the CSTR system allows for better process control, ensuring stable biogas production, but at a higher price.

2. Gas Engine

The Gas Engine function is to move and regulate the flow of biogas from the reactor to the purification or storage system. A blower is used to move the biogas gas through the system, while a gas pump helps move the biogas from one part of the system to another. Both of these machines are essential to ensure a stable and consistent gas flow.

3. Biogas Purification or Treatment

Biogas purification or treatment is the stage where the biogas is cleaned and treated to remove contaminants.

• Bioscrubber uses microorganisms to remove contaminants
• Chiller cools the biogas to reduce humidity and condensation.
• Filters remove solid particles and contaminants,
• Siloxanes that can damage equipment must be removed through the purification process.
• Flare serves as a safety system to burn gas that cannot be stored or used, reducing the risk of explosion or leakage.

4. Electric Generator

After the gas purification stage, the final stage is the conversion of biogas into electricity through the power house. The electric generator in the power house converts the purified biogas into electricity. The electricity produced can be used for various purposes, either for factory operational needs or sold to PLN. The sale of electricity must comply with applicable regulations, which will be discussed in the next section.

In addition to electricity, biogas can also be used as Co-Firing, and these benefits can be a source of long-term income. Click the following link to read related articles on what can be used from Biogas and its economic benefits.

6. Compressed BioMethane (CMB) 

Compressed BioMethane (CBM) is a biogas fuel that has been purified and compressed into pure methane, offering higher and cleaner combustion efficiency than fossil fuels. The purification process removes CO2 and impurity gases, resulting in CBM which is ideal as an alternative fuel.

In Malaysia, with many palm oil mills, CBM can be an efficient solution for fuel for transport trucks, from fruit to the final CPO product. In addition to the economic benefits of saving fuel costs, CBM also contributes to reducing carbon emissions and dependence on fossil fuels.

CBM can also be developed into BioLNG, with the added benefit of higher energy density. For more information, watch our webinar recording at the following link :