As a society, Spain has embarked on a transition to become a climate-neutral economy by 2050. Transforming the industry will be paramount to achieve this ambitious goal. The petrochemicals sector is the industrial sector whose future represents a Gordian knot due to the use of oil and gas in most of its products. This Master's thesis aims to study the transition of this sector by developing a standalone energy systems model focused on the petrochemical industry in Spain, using methodologies akin to those employed in the IIT’s OpenMASTER model suite. The student will model the industrial processes that are the major emission and energy hotspots of the industry, so as to evaluate their technological evolution towards a net-zero emissions paradigm by 2050. If time permits, the model will be expanded to include additional relevant processes, ultimately aiming to assess the impact of climate and energy policies to achieve climate neutrality in the sector.