Despite their promise of not competing with food production and having low carbon emissions, second-generation biofuels like bioethanol remain grossly underused. One notable reason is that the large-scale production of such biofuels requires a massive concentration of organic matter, such as lignocellulosic biomass. Moreover, due to difficulty accessing the polymer sugars in the biomass matrix, the production process is expensive and complex. As a result, there is little opportunity for small rural players to get in the game. But what if farmers could valorise the small biomass feedstock found locally and use it to produce biofuel? This is the challenge posed by the EU-funded BABET-REAL5 project. “BABET-REAL5 aims to develop the technical concepts and approaches needed to enable the small-scale production of biofuels,” says Gérard Vilarem, who serves as director of the Laboratory of Agro-Industrial Chemistry, president of the centre for technological resources, CRT, and BABET-REAL5 project coordinator. “Because this model is more favourable to regions that cannot provide high amounts of concentrated biomasses, it will support the development of rural economies.”
A compact, streamlined system
Most second-generation biofuel production processes involve several complex and expensive stages generating pollutants that need to be cleaned up. What BABET-REAL5 aims to do is streamline this entire process into a single, compact system. “Our main goal is to develop a compact system that can be easily installed in rural areas,” explains Vilarem. “We also want a process that ensures maximum performance and zero waste while consuming little energy – a real challenge when one considers the complex structure of lignocellulosic biomass.” Vilarem adds that the project also hopes to achieve techno-economic and environmental viability from processing just 30 000 tons of dry material annually, which is three to seven times less than the current business model. To do this, researchers created a prototype featuring a patented bioextrusion process that combines the various steps of the pretreatment phase into a single step. “The thermal, mechanical, chemical and biochemical reactions necessary to destruct the biomass and access the polymer sugar enzymes are now combined and performed at high throughput in one reactor,” explains Vilarem. Next, researchers combined this pretreatment phase with the saccharification and fermentation phases, which is where the sugars are separated from the biomass and transformed into ethanol. “We have implemented these two steps inside one single reactor,” notes Vilarem. “We also optimised them to demonstrate the feasibility of the entire continuous process, from pretreatment of the biomass to the production of ethanol at pilot scale.”
Technically, economically and environmentally viable
According to Vilarem, the project succeeded in accomplishing its main objectives: “The results demonstrate that most of the studied business cases are technically, economically and environmentally viable at small industrial scale.” Although the project has successfully advanced the new technical steps to pilot scale, they are still a long way from industrialisation. However, based on the encouraging results achieved during this project, the consortium is now considering developing a demonstration unit. During this stage, researchers hope to scale up the BABET-REAL5 technologies to industrial-scale production levels.
BABET-REAL5, biofuel, biomass, carbon emissions, second-generation biofuels, bioethanol, farmers, rural economies, ethanol