Crude palm oil is one of the more than ten renewable raw materials that Neste uses to produce a range of renewable products, including renewable diesel. Palm oil represents approximately 20 percent of the Helsinki, Finland-based company’s renewable raw material usage annually.

Neste, a major producer of renewable diesel refined from waste and residues, has recently focused on methane emissions at the palm oil mills. These facilities account for a significant share of life cycle emissions of palm oil products.

Belt press filtering of mill effluent reduced methane emissions at the pond by 50 percent. Source: Michael Giebels, Meo Carbon SolutionsThe effects of a newly applied effluent treatment method on such emissions were monitored for two years at palm oil mills in Indonesia and Malaysia. The treatment scheme involves the use of a belt filter press to separate solid organic matter from wastewater. The filter applies pressure to solids to squeeze out the water, and biosolids remaining between two tensioned porous belts are then compressed by a series of rollers.

To validate the emission savings from adopting the belt press method, the mill simply needs to weigh the belt press cake removed with the belt filter press and measure its carbon content. The amount of the belt press cake together with its carbon content provides the means to calculate removed organic carbon which, according to the study results, correlates with the reduction in measured methane emissions.

Removal of solid organic matter from wastewater was demonstrated to reduce greenhouse gas emissions by 50 percent from palm oil mill effluent ponds compared to conventional open-pond emissions.

Deployment of this method by all producers in Indonesia and Malaysia would result in a 4.5-million-tons-per-year reduction in greenhouse gas emissions. This is equivalent to removing 1.6 million passenger cars from the roads.

Additional environmental benefits can be realized with the belt filter press method, including reduced need for dredging the solid waste from the bottom of effluent ponds. The belt press cake is rich in nutrients and can be used at oil palm plantations as an organic soil enhancer, decreasing the need for store-purchased fossil fertilizers. Purified water from the press can be directed to an irrigation water system, reducing the need to derive irrigation water from other sources.