Empty fruit bunches (EFB) represent the largest proportion of biomass waste generated by palm oil mills, and their production continues as long as the mill remains in operation. Accounting for approximately one-quarter (25%) of the fresh fruit bunches (FFB) processed, a single palm oil mill can generate hundreds of tons of EFB waste daily. In reality, most of this EFB waste remains unprocessed, simply accumulating in and around the mill and posing a serious environmental hazard. With growing awareness regarding environmental issues, the zero waste concept, and sustainability, some palm oil mills have begun to process this biomass waste—which otherwise threatens to pollute the environment—into other products.

Traditional Methods for EFB Disposal

There are various ways to process empty fruit bunches, ranging from simple incineration—which often leads to environmental pollution through smoke—to their use as boiler fuel (following pressing and shredding), or their conversion into commercial products such as pellets, briquettes, or biochar. Burning EFB in incinerators remains the most common disposal method. However, because these incinerators are often rudimentary and lack emission control systems, the resulting smoke pollution is highly visible and noticeable.

If such incinerators were upgraded or equipped with emission control technology, this smoke pollution could be minimized—potentially even reduced to levels below the permitted emission thresholds. For palm oil mills that do not yet have an incineration unit but wish to process their EFB waste in this manner, it is essential to utilize an incinerator that has been upgraded or fitted with appropriate emission controls.

Mechanical Extraction of Palm Oil from EFB

In fact, there is an additional benefit to be gained from processing oil palm empty fruit bunches (EFB), regardless of the specific processing method chosen. This benefit comes in the form of palm oil recovered through mechanical extraction—specifically, by using a press on the empty fruit bunches. Beyond reducing moisture content, this mechanical extraction process yields palm oil.

Empty fruit bunches contain approximately 3% oil; this means that for every ton of EFB processed, 30 kg of palm oil can be recovered. Consequently, if an oil palm mill processes 200 tons of EFB per day, it would yield 6,000 kg (6 tons) of palm oil daily, amounting to 150 tons per month. Furthermore, this extraction process leaves the empty fruit bunches drier, which facilitates any subsequent processing steps. These empty fruit bunches are the output from the thresher machine; prior to this stage, they have undergone a sterilization process using pressurized steam for several hours, which increases their moisture content to approximately 70%.

The oil produced is of low quality due to its high free fatty acid (FFA) content. In large-scale palm oil mills, this oil might be blended with regular crude palm oil (CPO) produced by the mills themselves. Given that the volume of oil extracted from empty fruit bunches is small relative to the volume of regular CPO, such blending keeps the total FFA content below the required threshold, rendering it safe for use as edible oil. However, this may not be feasible for smaller palm oil mills. For palm oil with a high FFA content, the most suitable application is in the production of biofuels, such as biodiesel or even sustainable aviation fuel (SAF).

Selling palm oil with a high free fatty acid (FFA) content helps offset the production costs associated with processing empty fruit bunches (EFB). Furthermore, converting EFB into commercial products—such as potassium-rich ash (via incineration), pellets, briquettes, or biochar—can significantly increase profitability.

Specifically, in the production of EFB pellets, a leaching or washing process is often necessary to reduce the levels of potassium, sodium, and chlorine present in the ash. Lowering these elements makes the EFB pellets more “boiler-friendly,” bringing their quality closer to that of standard wood pellets. The chemical components in the ash that typically cause fouling in boiler tubes—due to their low melting points and corrosive nature—are reduced through this leaching or washing process. Additionally, pressing the EFB makes the leaching or washing process both more effective and more efficient.

Bottom Line

The processing of empty fruit bunches should yield both economic and environmental benefits. Producing palm oil from EFB generates additional profit, which has encouraged more widespread efforts to process them. The demand for crude palm oil (CPO) for use in biofuels—including in Indonesia, with its B-50 biodiesel program—is growing, as is the global demand for biofuels to support decarbonization. Consequently, palm oil extracted from EFBs should face no difficulty in finding a market. Given that Indonesia produces approximately 60 million tons of EFBs annually, there is a potential to produce 1.8 million tons of palm oil per year from this source.