Accelerating Bio Alcohol Upgrading Catalysis for a Prosperous Net Zero

Our proposal takes a promising technology for the production of sustainable biofuels, with the potential to make a significant contribution in the transition to a prosperous net zero, closer to commercial reality. The main current sustainable alternative to gasoline/petrol is bioethanol and this is now part of the standard fuel blend in the UK (E10 or E5). However, ethanol has drawbacks as a fuel; its energy density is relatively low (around 70% that of gasoline), it can easily retain water leading to separation problems in fuel tanks, and it has a proven tendency to corrode existing engine technology and fuel infrastructure. These factors limit blend ratios to those already achieved, i.e. around 10%. By contrast, butanol has emerged as a promising advanced fuel molecule with drop-in performance much closer to traditional fuels but is difficult to manufacture in a sustainable way at scale. In previous EPSRC-funded research, we have developed catalysts for the so-called Guerbet reaction that will upgrade readily-available small bioalcohols (methanol and ethanol) into butanols (n-butanol and isobutanol). This low-energy pathway using sustainable feedstocks to a fuel which is a potential drop-in replacement for gasoline has clear benefits. Using other related feedstocks (e.g. longer chain alcohols), this reaction can also be extended to other sustainable fuel types such as synthetic aviation fuels, expanding the benefit of this research even further. The performance of our catalysts in lab-scale batch experiments is promising but key technological questions remain, especially regarding the formation of unwanted solid by-products. These by-products are known to result from unwanted reactions with the water that is co-produced during the Guerbet reaction and there is good preliminary evidence that moving from a batch to a continuous process is the most viable route to remove this water and therefore supress by-product formation. The main aim of this project is to prove that a continuous process is viable and overcomes the current technological limitations. Specific objectives include identifying the reactor configuration, conditions and catalysts that will achieve this aim. Crucially, we will also transfer this knowledge to our industry partners by a series of actions including industry placements for key researchers. We will move this area to a higher technology readiness level and allow industry to make robust decisions in terms of the investment that is needed for the next stage of development. The potential benefits of this project are significant, in that it could unlock the potential of a technology which could be widely deployed across the manufacture of sustainable liquid fuels, accelerating the adoption and impact of this technology as a positive contribution to achieving net zero.