Revolutionising biomass processing
8 September 2023
Plant and animal matter, known as biomass, is a renewable resource that can be replenished. Biomass can produce biofuels and chemicals that can generate electricity and heat, and also be used for transportation. The importance of biomass in the energy sector lies in its ability to replace fossil fuels, such as coal, petroleum, and natural gas, which impact the environment. By converting biomass into energy, we can reduce our dependence on fossil fuels and reduce greenhouse gas emissions to tackle climate change. In 2017, the International Energy Agency (IEA) described bioenergy as the most important renewable energy source.
Dr Arshad Salema from the School of Engineering at Monash University Malaysia and his team are at the forefront of biomass research with their alternative microwave pyrolysis technology. By utilising this cutting-edge technique, the team is able to convert biomass into value-added products such as biochar, bio-oil and syngas.
Pyrolysis and gasification are processes that convert biomass at a high temperature to a variety of products depending on the process conditions applied. Traditionally, this is done by using an electrical heat source. This allows heat to transfer from the outside of the biomass to the core through conduction. However, this process is time-consuming and can lead to high heat losses.
Therefore, Dr Arshad's team is using microwave radiation to valorise the biomass. Microwave radiation is a highly selective, rapid, volumetric, and non-contact heating method. This means the biomass heats rapidly without direct contact with the heat source. If biomass is added with microwave susceptors, it would significantly save process time and improve product quality.
Dr Arshad's team specialises in converting biomass consisting of oil palm, wood-based, coconut shell, and rice husk to biochar, bio-oil and biogas using microwave pyrolysis and gasification. Their vision is to scale up the system at an industrial scale.
Although microwave technology is a promising biomass conversion method, it's still not used on a large scale. A few challenges must be addressed before microwave technology can be scaled up. These challenges include reactor design, temperature measurement, process conditions and the use of microwave absorbers or catalysts.
His team is working on solving some of these critical challenges, including temperature measurement during microwave heating through experiments and numerical simulation methods. Although some of the critical issues need to be addressed, he believes that microwave-assisted biomass pyrolysis is a promising method to be scaled up at a commercial stage in the future.
Dr Arshad and his team recently published a classical review article in a top 1% Journal, Renewable and Sustainable Energy Reviews, that discusses the technical challenges of scaling up microwave technology for biomass processing that has received excellent citations among the microwave processing community worldwide.
"As we delve into the potential of biomass and its transformative energy possibilities, our research endeavours are fueled by the vision of a cleaner, sustainable future. Microwave-assisted biomass pyrolysis stands at the forefront of innovation, and we are committed to overcoming technical challenges to scale up this game-changing technology. Our pursuit is driven by the hope of a net zero tomorrow, where renewable resources lead the way towards a healthier planet for generations to come," stated Dr Arshad.