As the world becomes increasingly concerned about climate change and the depletion of fossil fuels, the need for clean and sustainable energy has become more pressing. To address this challenge, the European Union funded the project CLARA (Chemical Looping gAsification foR sustainAble production of biofuels), which involved collaboration between 13 partners across Europe, including universities, research centers, and industrial partners.
The objective of the project, completed in 2022, was to enhance the development of chemical looping gasification (CLG), a technology that had only been studied on a laboratory scale with feedstock inputs up to 25 kWth.
The innovative CLG process uses an oxygen carrier that is cycled between a fuel and an air reactor to provide oxygen for partial conversion of the biomass feedstock. One of the benefits of CLG is that high quality syngas with low nitrogen content can be produced without an air separation unit. Avoiding air separation has high potential to improve the overall conversion efficiency and the economic feasibility of biomass gasification.
The project aimed to accomplish this by using a range of pilot plants up to a capacity of 1 MWth for large-scale production of second-generation liquid biofuels based on CLG of biogenic residues such as wheat straw, pine wood residues, and industrial wood pellets.
The CLARA project was designed to test and enhance the CLG process in an industrially relevant environment at a 1 MWth scale. The ultimate goal was to elevate the process to market maturity, enabling large-scale deployment. Additionally, the project sought to optimize innovative, cost-efficient technologies for biomass pre-treatment and syngas cleaning while supplementing these with established fuel synthesis technologies such as the Fischer-Tropsch process. By doing so, the project aimed to establish a sustainable source of biofuels and enable the full biomass-to-biofuel process chain.
The CLARA project achieved several key milestones, including successful testing of CLG at a 1 MWth scale with the three types of biomass feedstocks, development of a layout for a full-scale (200 MWth) biomass-to-liquid plant, and evaluation of technical, environmental, economic, and societal risks associated with the entire process chain. The project also defined the final pre-treatment chain for the utilization of wheat straw in CLG and filed a patent for a gas cleaning process using KMnO4 instead of H2O2. Techno-economic assessments made by the CLARA project also indicate that favorable syncrude prices are achievable, especially when considering CO2 credits. As a result of these accomplishments, the CLG technology was elevated from TRL 4 to TRL 5/6.
The forest-based sector has a significant role to play in the production of renewable energy. The CLARA project represents an important step forward in developing innovative and efficient technologies for the large-scale production of advanced biofuels, which could help to reduce greenhouse gas emissions from the transport sector and pave the way for a more sustainable future.