Biomass turned directly to fuel
To create energy from biomass, cellulose and lignin are usually extracted from plant-based materials and fermented to form biofuels. Scientists recently developed a new technology, called torrefaction, which allows biomass to be used directly as fuel in a way similar to coal. The EU-funded SECTOR (Production of solid sustainable energy carriers from biomass by means of torrefaction) initiative developed the technology further to pilot scale and beyond. Twenty-one partners from nine European countries worked towards introducing torrefaction-based bioenergy to the market within the next few years. As a result, the torrefaction technology has matured significantly to the point of market readiness and user requirements satisfaction. Torrefaction is a process whereby biomass is converted to a coal-like material by heating it in a low-oxygen environment to reduce moisture and mass. When compressed into pellets or briquettes, it becomes a high-energy carrier that is between three and five times denser than the original biomass. Researchers gathered data on woody and agricultural biomass from 21 feedstocks in laboratory, pilot and demonstration tests. They improved the torrefaction process to lower costs, and tested the resulting pellets for their potential to be stored long term and ultimately commercialised. Follow-up assessments on the pellets' safety, techno-economic value and sustainability revealed that torrefied fuels are superior to traditional biomass products like white wood pellets. While torrefied fuels are potentially cheaper than coal-based fuels, the study concluded that they would not be competitive in the current European market of co-firing within coal fired power plants. Market strategies should instead focus on small and medium applications (heating, combined heat and power) and on opportunities in African and Asian countries, which currently have no traditional biomass carrier routes. In Europe, a supportive emissions scheme would be needed to make first investments in large-scale green power generation from torrefied biomass possible and reassuring before further market deployment.
Keywords
Biomass, pellet, renewable energy, biofuels, energy carriers, torrefaction
