The world is slowly moving away from the use of traditional fossil fuels for energy towards using more renewable sources in order to address climate change and global warming caused by excessive greenhouse gas emissions. In Indonesia the government has rolled out B30, a fuel blend of 30% biofuel and 70% conventional diesel as a fuel source to be used in nationwide commercial transportation. The biofuel used in B30 is made using fatty acid methyl esters (FAMEs). These FAMEs are categorized as first generation biofuels, meaning that they are considered to be unsustainable and result in massive deforestation as a result of industrial plantation expansion.
Indonesia is the world's largest producer of palm oil producing more than 35 million tonnes annually. The rapidly expanding industry is hugely wasteful with the oil extracted making up as little as 10% of the total biomass produced – meaning the remaining 90% of that biomass is classified as waste. The unsustainable production of palm oil is one of the biggest threats facing the forests and wildlife of Indonesia.
One method of reducing the amount of wasted biomass is to use the 90% ‘waste’ biomass to derive fuel from, meaning that less damage will have to be done to the rainforests in order to reach oil quotients.
The palm oil empty fruit bunches (POEFBs) are categorised as waste and can be used to create second-generation biofuels – biofuels which are made from abundant and non-competitive biomass waste. The POEFBs are rich in lignocellulose feedstock, the lignocellulose can be turned into bio-oil by pyrolysis and then into biofuel via the removal of oxygen by hydrodeoxygenation (HDO). A catalyst is needed to perform the HDO process and the search for a suitable sustainable catalyst remains a challenge. In order to overcome this it was suggested that biochar (BCR) could be used as an option. It is produced during the pyrolysis process and is an ideal candidate due to its oxygen-containing functionalities. Whilst it can be returned to farm fields as a fertiliser using BCR as a catalyst for the HDO stage would create a net-zero pyrolysis process.
Whilst BCR has already been successfully used to produce FAMEs its use in creating second generation biofuels has not yet been fully explored. In order to better understand the catalytic ability of BCR in this process, it was characterised by several techniques including inelastic neutron scattering at the ISIS Facility to help better understand the functional groups on the BCR surface that influence its catalytic ability for HDO.
The analyses revealed that further improvement of the catalytic activity might be achieved by using BCR as a catalyst support alongside the already widely studied catalysts currently in use. This was a positive result as it helps further reach the goal of carbon neutrality, and thus far less negative environmental impact, for this process.
The lead author of this paper, Dr Indri Badria Adilina, has previously won ISIS’ 2019 Economic Impact award for her work on reducing Indonesia’s reliance on fossil fuels. Her previous work was closely related; during her stay at ISIS in 2019, made possible by the Newton Fund, she used neutrons to help better understand the chemical compounds in biomass waste and their interaction with the catalyst, her results leading onto the design of a catalyst made from bentonite clay, a renewable and abundant resource in Indonesia.
“The physicochemical properties of BCR vary significantly based on the type of raw biomass materials and production techniques employed, hence, it is imperative to understand the surface characteristics of BCR, as tailoring its catalytic activity would be challenging without such knowledge. We were able to gain valuble insights regarding this matter using neutrons at the ISIS Facility.” - Dr Indri Badria Adilina, Lead Author