The European Union aims to reduce greenhouse gas emissions by 80% to 95% below 1990 levels by 2050. For the Netherlands, a reduction of 80% implies that a limited amount of 30 Mton CO2 per annum may be emitted in 2050. Such a reduction could especially affect the Dutch refining industry as it is a large emitter of CO2 with a total of 11 Mton of CO2 in 2015. Assuming that the CO2 budget of the Dutch refining industry also decreases, investments are required that in alternatives that reduce CO2 emissions. However, due to increasing competition, decreasing European oil demand and thin refining margins these investments cannot be taken for granted. The main research goal of this master thesis is to “To explore the Dutch refining industry, determine the different factors that contribute to their CO2 emissions and assess which CO2 reducing alternatives are the most promising”. The Dutch refining industry contains 6 refineries of which 5 are located in the port of Rotterdam. Allocating CO2 emissions to individual processes shows that the atmospheric distillation unit is most cases the largest emitter of CO2. Other polluting processes are the FCC unit, hydrocracker and flexicoker. Besides the effect of the refining processes, the CO2 emissions of Dutch refineries are also influenced by their crude oil intake. CO2 emissions increase if crude oil has a lower API gravity (heavy) and a high sulphur content (sour). A wide variety of CO2 reducing options is identified within this master thesis which are assessed by an extended Technology Assessment that incorporates economical and institutional perspectives. In the end, a multi-criteria analysis, that includes the perspectives of multiple actors, is used to identify the most promising CO2 reducing alternatives. It can be concluded that heat exchange, optimisation of the distillation unit, processing lighter and sweeter types of crude oil and CCU are the most promising CO2 reducing alternatives.