Carbon Carriers Driving the Net-Zero Future: The Role of Torrefied Biomass Pellets in Power-To-X

Abstract

The latest Intergovernmental Panel on Climate Change Sixth Assessment Report urgently calls for sweeping action to mitigate the unprecedented impacts of climate change. The path to a carbon-neutral future is intricate, necessitating a multi-faceted approach that integrates decarbonization, defossilization, and energy/resource efficiency. Power-to-X (PtX) stands as a technological linchpin, converting renewable electricity into a range of sustainable products, from fuels to chemicals. However, its full potential is intrinsically tied to the availability of sustainable carbon sources. This paper evaluates the various avenues for carbon sourcing for PtX: direct air capture (DAC), biogenic carbon, and Long-cycle Industrial Carbon. DAC, although promising for the long term, has limitations in scalability and land requirements. Industrial long-cycle carbon capture technology is improving but requires a thorough Life Cycle Assessment for evaluating its sustainability. This study examines the environmental impacts, scalability, and logistical considerations of each carbon source. Biogenic carbon offers a near-term solution, and its various forms could simplify transportation logistics. An analysis of gasification processes, syngas cleaning, and hydrogen integration was conducted to assess the technical viability of these carbon sources in PtX applications. The results show that torrefied biomass pellets, after a thorough technical assessment, present a globally feasible and sustainable carbon carrier, setting the stage for industry standardization and easier global transportation. Syngas produced through the gasification of the pellets complemented by green hydrogen can be utilized in Fischer–Tropsch, methanol synthesis, and methanation, allowing PtX to synthesize practically any type of organic compounds in a hybrid Biomass–PtX (HBPtX) process. This study provides key insights for industries and policymakers by demonstrating the technical feasibility and sustainability of torrefied biomass as a carbon carrier, thereby supporting the development of comprehensive climate mitigation strategies.