In this insightful second episode, Roberta Cenni, the head of biofuels at the Maersk McKinney Mueller Center for Zero Carbon Shipping, delves into the potential of biofuels as a sustainable energy source for the shipping industry. With biodiesel currently being the only commercially available biofuel derived from fats, oils, and greases, she discusses its limitations due to supply constraints and explores the possibilities of other biofuels like biomethane and biomethanol, which could be produced from waste materials through processes such as gasification and pyrolysis. Cenni elaborates on the technical aspects of converting biomass into valuable fuels, highlighting methods like gasification that converts biomass into synthesis gas for methanol or synthetic diesel production, and pyrolysis, a less energy-intensive process for breaking down solid substances. She also touches on hydrocracking and hydro treating processes that use hydrogen to upgrade biocrude or clean feedstocks of impurities. Additionally, the conversation covers the potential of ammonia as an alternative fuel, despite its toxicity risks, emphasizing the importance of safety in its maritime use. The episode not only provides a deep dive into the science behind biofuel production but also stresses the significance of using waste biomass sustainably. Cenni's discussion underscores the need for responsible sourcing practices to prevent negative impacts on biodiversity and ensure the sustainability of biofuel production for the shipping industry. Through a comprehensive exploration of biofuels, from their current state to future potentials and challenges, this episode sheds light on the critical role of innovative energy solutions in achieving zero carbon shipping.