MAB-Bitumen: Next-generation bio-bitumen for the roads of the future

Background

Bitumen is a viscous, sticky substance extracted from crude oil. It is an important material used as an asphalt binder for road construction and other paved areas. It is also used in other various civil engineering applications, such as adhesives, sealants, preservatives, and waterproofing agents. The estimated global annual production of bitumen is 130 million metric tonnes. According to Eurobitume, the EU produces around 15 million metric tonnes of bitumen every year. The UK produces about 727,000 metric tonnes and imports around 1.2 million metric tonnes (Statista, 2021). For road construction, sticky bitumen is mixed with aggregates such as crushed rock, sand and gravel to create asphalt, which binds it all together to build roads. The US National Asphalt Pavement Association (EAPA) in “Asphalt in Figures 2021” reports that an average of approximately 624 million tons of asphalt are produced every year, only between Europe, the US and South Africa.

Eurobitume asserts that bitumen is a sustainable construction material, has a minimal environmental impact during its use/service phase, and, as an asphalt binder, is entirely reusable. However, Eurobitume estimated 208 kg CO₂e/t bitumen, whereas ESU-services Ltd estimated 720 kg CO₂e/t bitumen in a separate study (Jungbluth et al 2019). Estimating that each ton of asphalt contains 4% of bitumen, and 25kg of CO₂ per tonne of asphalt (direct emission according to Hanson UK, 2022), the annual global production of asphalt is estimated to produce an equivalent of 15.6 million tons of CO₂ emission, with approximately 5 million tonnes (or around 17 million tons using ESU figures) from bitumen alone.

Apart from environmental concerns, the depletion of crude oil reserves is a serious issue for the construction and waterproofing industries. Therefore, the development of new sustainable alternatives for petroleum-based bitumen is urgently needed to help road industries cut carbon emissions and reach net-zero carbon targets by 2050 (see the National Highway’s Net Zero 2030/240/2050 plan).

The ‘MAB-Bitumen’ project is committed to finding innovative solutions to this problem by creating pioneering grades of bio-based bitumen for different industrial and engineering applications. Through our collaboration with leading industries and academia, we are determined to pilot, develop, and scale up our technology, paving the way for a more sustainable future.

What is MAB-Bitumen?

Microalgal-based biohybrid bitumen (MAB-Bitumen) is a novel bio-based bituminous material that is produced by using specific strains of microalgae either alone or blended with other bio-based materials. The resulting material offers numerous advantages over conventional bitumen, including superior mechanical properties, environmental sustainability, and cost-effectiveness.

Microalgae are tiny photosynthetic organisms that grow quickly and absorb high amounts of CO₂. They can also assimilate nutrients like nitrogen and store excess phosphate inside their cells, and they have a high capacity for producing lipids. Our MAB-bitumens are created by partially carbonising the initial algal biomass in an oxygen-limited environment to make carbon- and lipid-rich material. The high lipid and nutrient content in the MAB-bitumens makes them highly attractive due to their viscoelastic and adhesive properties, which are similar to those found in petroleum-based bitumen. This material has unique characteristics, and our ability to adjust its chemical and visco-elastic properties makes it suitable for various industrial applications, including road construction and waterproofing.

Fig1: Schematic illustrating the process of creating our MAB-Bitumen material and its industrial applications.

Consortium Team

Together with CO2CO, Nanolyse Technologies Ltd, Imperial College London, the University of Sheffield and UK asphalt industry leaders, we form a powerful collaborative consortium committed to driving innovation and creating a better, more sustainable future. The MAB-Bitumen executive team and partners are shown below.