05 March 2015

Reducing methane formation makes palm oil more environmentally friendly

Article

The formation of methane during palm oil production can be reduced by filtering organic matter from the wastewater. Instead of emissions, this produces useful and more environmentally-friendly soil for palm oil mills.

Methane is an extremely strong greenhouse gas. It is generated when wastewater from an oil mill is treated during palm oil production. The amount of greenhouse gas emissions can be cut/ reduced by capturing methane or even by reducing the methane formation generated by the process. “A palm oil mill was able to reduce its annual emissions by an amount equal to around 10,000 tons of carbon dioxide,” says Annamari Enström, Researcher at Neste Oil.

This illustrates the significance of the issue. Produced by Neste Oil, NEXTBL renewable diesel can be used to reduce greenhouse gas emissions by 40–90% compared to fossil fuels. Methane capture and reduction are efficient ways to achieve even larger reductions in emissions.

What is this all about?

During palm oil production, greenhouse gas emissions are generated when wastewater is treated after oil pressing. The water discharged by the process has a high content of organic matter. When the water is treated in large ponds, the organic matter may begin to decompose. Larger molecules break down, generating methane and carbon dioxide. “Methane absorbs heat much more efficiently than carbon dioxide. According to calculations made by the EU, methane is 23 times stronger than carbon dioxide as a greenhouse gas,” says Enström. For this reason, reducing methane emissions is extremely important. There are at least two ways to do this.

Two ways to reduce emissions

The biogas generated by palm oil production can be captured. If wastewater is directed into ponds, they can be covered to allow capturing biogas for electricity production (and other reuses). Biogas can also be captured by directing wastewater directly into a bioreactor. The electricity produced can be used locally, and the surplus can be directed into the electricity grid.

According to Enström, this is a sensible way to reduce emissions, as methane can be used to replace fossil fuels in electricity production. When combusted, methane mainly emits vapor and carbon dioxide, which considerably reduces greenhouse gas emissions. In addition to benefiting the environment, this benefits the local community. Another way to reduce emissions is to reduce methane formation. Organic matter can be removed from water chemically or through filtering, for example.

“A combination of chemical precipitation and filtering can be used to remove more than 98% of the organic matter from water. The remaining substance can resemble a rich black soil,” says Enström. Plantations use this nutrient-rich substance to improve soil quality. The purified water can be directed into an irrigation system.

A win-win project

Methane capture or reducing the formation of methane is gaining ground in palm oil production. Neste Oil is promoting this change. The company is encouraging producers to use the new technology and helping oil mills introduce new operating methods. “These are projects where everybody wins,” Enström points out. Methane is captured, emissions decrease, the need for artificial fertilizers decreases and renewable products become more environmentally friendly. In addition, land is often freed up for better uses.