Victoria V. Beltran

This study presents a comprehensive life cycle assessment of the production of biofuels from microalgae by hydrothermal liquefaction, focusing on the valorization of CO₂ emitted by the cement industry, which represents about 8% of global anthropogenic emissions. The results demonstrate that hydrothermal liquefaction is a promising option for producing biofuels and highlight the importance of understanding its environmental impact in order to ensure its sustainability. OpenLCA 2.6 software was used to analyze the greenhouse gas (GHG) emissions associated with the process, and it was found that it can capture 3.91 kg of CO₂ per kg of biofuel produced compared to 0.286 kg of CO₂ per kg of fuel emitted by petrochemical diesel. This article also discusses the financial potential of the technology through the reduction in capital costs due to the elimination of taxes and tariffs under the current policies in Colombia, including the benefits of carbon credits, and finds that the classification of these processes as environmental facilitates their implementation at the industrial level. In conclusion, the capital investment can be reduced by about 15% with an estimated MUSD 165, and the project would be profitable, producing around 850 barrels/day of biofuel under a medium scenario with a carbon bond price of 5 USD/ton CO₂, capturing an estimated 20% of the CO₂ emitted at the Cementos Argos plant in Cartagena, Colombia.