Microalgal biomass as a sustainable alternative to bitumen in road construction

点击翻译按钮获取中文摘要

Asphalt is one of the oldest road-building materials known to man. The great versatility of asphalt is due to its petroleum-based component, bitumen. Bitumen is considered non-sustainable given its reliance on fossil fuels and is used in surfacing over 95% of major roads and highways in the UK, USA and Europe. It is responsible for the biggest carbon emissions in the construction industry, besides steel and cement. Can we use bio-based bitumen at a large scale to make our roads greener anytime soon?In this project, we work together in a strong collaborative consortium involving CO2CO, the University of Sheffield, Imperial College London, and Nanolyse Technologies with strong links to the value chain, supported by leaders of the UK asphalt industry. This collaborative innovation project is focused on assessing the feasibility of establishing a sustainable alternative to bitumen by developing bio-based bitumen from microalgal biomass. This programme is driven by the need to mitigate the worst effects of climate change by reducing CO2 emissions in all road operations and adopting net-zero approaches to building new roads and road maintenance.Microalgae have rapid growth rates and are able to assimilate nutrients such as nitrogen and phosphorus, as well as other elements. The production of this algal biomass provides a cost-effective and environmentally friendly solution for carbon sequestration through photosynthesis. Bio-based bitumen (or bio-bitumen) is produced by the partial hydrothermal carbonisation of the starting algal biomass in an oxygen-limited environment. Bio-bitumen is a sticky material with viscoelastic properties that contains high lipid and nutrient content, which gives rise to some unique characteristics that make this material attractive for different industrial applications, including construction, waste management, wastewater treatment, catalysis, and agriculture.We will examine the feasibility of developing different grades of carbon-negative bio-bitumen from microalgal biomass. By replacing petroleum-based bitumen binders with renewable bio-bitumen, we help the UK road construction industry become greener and more sustainable. We will also investigate the technical, economic, and environmental aspects of the whole life-cycle of bio-bitumens.Following the successful early collaborative research working with algal biomass, macromolecules, and their thermal transformations, the project team will target the potentially massive UK and global market for asphalt binders where a sustainable, environment-friendly, constant, and cost-effective resource supply is required.