Why is this research needed?

In recent years, combustion of sustainable biomass has been identified as a suitable replacement for fossil fuels, resulting in net-zero carbon emissions. Biomass energy with Carbon Capture and Storage (known as BECCS) would therefore not only minimise carbon emissions in the power generation sector, but also it will effectively lead to negative carbon emissions – a technology vital to mitigate adverse climate change impacts.

Although BECCS has been recognised by the Intergovernmental Panel on Climate Change (IPCC) as an inseparable technology to effectively mitigate climate change, its large-scale deployment is currently challenging due to the high costs associated with the conventional carbon capture part of the process. Therefore, devising an effective yet economically-feasible process for in-situ carbon capture from biomass combustion power plants is a timely research gap to be filled urgently.

What is this research investigating?

This research aims to investigate the potential of raw and surface-modified UK-based biomass ash (BCA) as adsorbent in post-combustion CO₂ capture. In the first phase of the project, industrial BCA generated in the UK will be fully characterised and then modified to increase its adsorption capacity and kinetics for CO₂ capture. In phase 2 of the project, the actual adsorption/desorption process will be studied via thermogravimetric analysis and a fixed-bed column, designed and built at Brunel University London.

In this research, the Principal Investigator will use the industrial-grade BCA that has been supplied by a biomass-combustion power plant in the UK. The generation of BCA is expected to grow in the UK; for example, Drax, the largest power plant in the UK, has converted four out of its six boilers into biomass burning with plans to fully discard coal combustion in the near future. This creates a soaring volume of BCA in the UK within the forthcoming years. The physicochemical properties of BCA are different from that of coal ash; therefore, BCA must be handled differently. Owing to its chemical nature, modified BCA has a good potential to be used as an adsorbent for CO₂ capture. The utilisation of BCA as an effective yet economical adsorbent for in-situ CO₂ capture can therefore significantly reduce the associated capture cost using a co-generated waste during biomass combustion.

What does the research hope to achieve?

This research strives to pave the way for accelerated deployment of BECCS – a negative carbon emission technology – via a cost-effective yet efficient post-combustion carbon capture process, helping the UK meet its recently-announced target of zero greenhouse gas emissions by 2050, under the terms of a new government plan in mid-2019 to tackle climate change.