Sequential biochar systems in a circular economy

Despite the immense development of biochar technology during the last decade, we still await its widespread adoption in agriculture and beyond. Current obstacles for biochar are based on limited economic attractiveness arising from its dual nature as a renewable, multifunctional material in competition with fossil-based, single-use alternatives, and its parallel purpose as a carbon negative emission technology. While the combination of these properties makes biochar unique, monetising these double benefits presents difficulties. In this chapter, we evaluate the perception of biochar as a product and identify intrinsic problems of underlying concepts. Sequential biochar systems are introduced as a novel utilization strategy, based on the identification of biochar as a carrier for environmental services rather than a product. The proposed service-oriented concept enables changes in biochar’s pricing mechanism and increases its economic competitiveness without the need for further improvements in production or application. Recycling of biochar is used as a novel way to utilize biochar's multifunctional properties while connecting different industrial sectors and resource streams. We discuss the transformation and transfer of resources with biochar, the integration of sequential biochar systems into circular economy concepts, and arising synergies from this novel area of research. Two examples of sequential biochar systems, based in an industrial and an agrarian context, are proposed and explained in detail.