9 April 2014

Living sustainability:Better greenhouse gas balance for renewable diesel by reducing methane emissions


The majority of the CO2 emissions generated by fossil fuels are released during end-use, while most emissions from renewable fuels are linked to producing the feedstocks used for refining them. In the case of waste-based inputs, farming and processing account for the most emissions. To further enhance the greenhouse gas emission reduction (40–90% compared to fossil diesel) offered by renewable diesel, Neste Oil is investigating a variety of opportunities for reducing CO2 emissions during the production of the renewable inputs it uses.

When producing palm oil, one of the inputs used in refining renewable diesel, greenhouse gases are generated in the open basins used when treating wastewater from pressing plants. Wastewater contains high levels of organic matter, which breaks down into methane and CO2 over time. Recovering these gases and using the recovered methane to generate electricity can reduce emissions. Recovery facilities call for major investments, however.

Separating out organic matter from wastewater as it leaves pressing plants would be one alternative solution, as it would prevent methane and CO2 from being formed. Organic matter can be recovered in a number of ways, by filtration for example. By removing organic matter, the remaining water and sludge can be treated more cost-effectively and the decomposition process that generates methane can be minimized. Organic residue can also be refined into fertilizer for plantation use and reduce the need for chemical fertilizers.

Methane is 20 times more potent in terms of promoting climate change than CO2, according to Neste Oil’s Sustainability Manager in Singapore, Adrian Suharto.

“Because of the major climate impact that it has, recovering methane or preventing it from being formed in the first place are highly effective ways to reduce the overall level of greenhouse gases generated by renewable fuel.”

Benefits for village communities as well as the environment

Reducing greenhouse gas emissions is far from being the only benefit to result from methane recovery, as methane can also be used to generate electricity, benefiting not only pressing plants but local communities as well.

“When pressing plants are able to generate their own electricity, they can make major savings in their fuel costs,” explains Adrian. “And if a plant is grid-connected, it can earn extra income by selling its surplus electricity to the grid.”

Given the high level of investments involved, only a fraction of palm oil pressing plants in Malaysia and Indonesia currently have methane recovery units in operation. Although Neste Oil does not own any palm oil pressing plants or oil palm plantations, its aim is to help palm oil producers acquire methane recovery systems or equipment to help prevent it being generated in the first place, and it is working on a number of research, funding, and collaborative-based alternatives.